Car question
Has anyone ever tried getting those tiny little scratches from years of windshield wiper use buffed out? Our car is getting old, but it's running great. Only complaint I have with it is that the windshield is a little hard to see through when the sun is low. There are no deep scratches, just the hazy looking fine scratches from washing a dirty windshield with the wiper blades.
How much does buffing it out cost? Does it work? Is it something you can do yourself?
1) Be sure you have full glass coverage on your insurance policy.
2) Call your insurance company and say you need a new windshield because you can no longer see out of the old one.
Depending on your company, they will have no problem with this. If they do, hit the window with a ball pein hammer and tell them a rock flew off a truck tire w/o mudflaps.
Imagining glatt as Gary Cooper in The Fountainhead: "NOW it's broken and needs to be replaced." ha ha ha
I am noticing the glare formt he scratches on the Focus windshield at the moment, i think it's the low sun when I drive.
back in the UK we had an old car and once it got a chip and the repair guy said a repair is free, a whole new windhshileld is 50 quid deductable.
I went with a whole new screen and thought it was well worth it.
I just had a chip repaired on the Focus so asked about it, apparently the deductible for a replacemnt is $250 :(, my agent said if it needed it they could recommend local shops that would probably do it cheaper and not go through the insurance. :eek:
You should check your company and see if they offer full glass coverage. There should be no deductible. Full glass coverage is usually only about $50/yr but may only be available if you carry comprehensive coverage.
I'm pretty sure this car is so old we got rid of the insurance except for liability.
I see
kits for buffing windows with an abrasive compound for like $50. Anyone ever use one? Unfortunately, I don't have a compressor set-up, so air tools don't do anything for me. I can't use one.
I buffed out headlight lenses with a corded drill and attachment that was $20. I used fiberglass rubbing compound. I know its a different surface material, but was just sharing that experience.
The "kit" we bought to do the headlights didn't work at all.
A pro may be able to do it properly, but the people I've seen people try the abrasive compounds, all ended up with distortions.
I've found it easier to just run into Philly, and have them pop in a new one for $160.
Another tack might be to fill the scratches with something that has a similar refractive index. Canada Balsam is used to cement lens elements together, so as long as you only use your car in nice weather...
What about rainx?
Depending on your company, they will have no problem with this. If they do, hit the window with a ball pein hammer and tell them a rock flew off a truck tire w/o mudflaps.
I heard that! :mad:
I got my oil changed, and they reccommend I replace my tires. They're 2 years/20000 miles old. It seems soon; the car manual says there should be annual checks after five years.
But maybe the tires were low quality when new, or the snow last winter took a toll, or my driving style uses them up. I have noticed they squeal on one sharp turn on my commute even if I'm driving 15mph.
sounds like you need to put air in them. Thats very common with the weather change after a long hot summer.
I've been doing that... a lot. The tire pressure light goes on with every temperature change and more, and I had one pressure sensor replaced when it had a slow leak itself (according to the garage, who couldn't find any other leaks). The dealer says they "reset" the sensor, so maybe it was the computer instead of the tires.
But I have been keeping them full.
Are you checking them with one of these?
ok then what computer and/or sensor are you talking about?
The dealer says they "reset" the sensor, so maybe it was the computer instead of the tires.
I'm not certain what exactly was reset in the pressure sensor system; the sensor(s) in the tire(s) and/or the computer.
I've had bad luck with the pencil style tire pressure gauges. The dial kind seem a lot better to me.
I'm guessing there is some onboard computer that tells you when your tires are low. Is that it?
@ glatt - yeh me too, but for ease of recognition I posted the other. I think they are more common.
Yeah. There's a dashboard indicator light, so it's a good assumption there's software for it in the computer.
gotcha. Thats where the confusion was.
Oh, right. The indicator goes on, but it doesn't tell me much, so I then check each tire with a gauge.
I hate to be greedy when most cars don't have a dashboard light at all, but it would be very nice if the indicator could show which tire(s) were low. The computer must know; it probably even knows the PSI, but all it shows is the flat tire symbol.
Yeh all that seems a bit much to me. What kind of car is it anyway?
Civic Hybrid with the beta pressure gauge?
I heard that! :mad:
O hai Brian. :blush:
I always thought you were just supposed to do the penny test on the tread...? Or is the mechanic the one telling you it's a hypothetical slow leak that's causing the need for replacement, not the tread?
I suspect the style of driving, mostly urban, with a high ratio of turning to miles driven, is taking it's toll. 20K is a lot of miles under those conditions. Stick to tire pressure posted on the door jamb sticker. If it's a range, use the high end.
It's easy enough to tell if the tires are worn out, as the
wear bar will show across the tread.
They reccommended replacement due to the tread. I haven't checked it myself, but if 20000 is a reasonable replacement time for urban driving, I expect they're right.
The slow leak issue was a different garage; a tire was low less than two weeks after I had filled them, so I asked them to look at it. Their verdict was replacing the pressure sensor due to a slow leak around it.
They recommended replacement due to the tread. I haven't checked it myself, but if 20000 is a reasonable replacement time for urban driving, I expect they're right.
20,000 miles was why almost all American tire companies were sold to foreigners. Radials in the early days did at least 40,000 miles. 10K and 20K were what were obsolete technology bias belt tires did before 1975. Yes, 10K and 20K is that much unacceptable.
How did the tire wear? Equally across the tread?
My first Honda Accord did 107,000 miles on the first set of tires. My second Accord only did 98,000.
All tires work just fine even at 20 PSI. But because Firestone was intentionally making tires that killed people, then hyped 'low pressure', well many are still brainwashed by that myth.
You maintain higher pressure so that tires last longer. But no radial tire must wear out in 20,000 miles. Again, because so many will ignore the question - How did the tire wear? Describe it.
Tire sensor: none are calibrated. You inflate the tire. Then tell the computer when the sensor's number is perfect pressure. The computer says low pressure when that number changes too much. But if not told what is normal pressure, then a computer may define normal pressure as low pressure. The whole thing is really unnecessary - a legacy of Firestone (now called Bridgestone) that was intentionally killing people. Then blaming a car owner for myths such as low tire pressure.
The car maker picks the oem tire for the attributes the want, and calculates the proper pressure from the cars weight so the tire will keep its tread flat on the road. Too high, or low, pressure will cause the tire to wear out the center or edges of the tread prematurely.
Also, it seems Civics for '06, '07, and part of '08, have a control arm problem, that causes vibration and tire wear.Ive worked in used cars for a dealership for 10 years, buffing will make the glass "look" better but wont change the integrity. Glass pros can fill chips and stop cracks from spreading but no miracles when it come to wiper wear.Time for a new windshield
Welcome to the Cellar, dschuyler. :D
I think you're right, time to find an affordable new one.
I got about 10,000 miles on the last set of tires on my motorcycle, but they were pretty worn out by the time I replaced them. In fact, they were so thin along the center that you could see the air inside.
Bikes are a whole other case, because you're using sections of the tread at different times, unlike cars that try to keep the tread flat as much as possible.
A squealing tire on a car, at 15 mph, indicates low tire pressure (likely) or faulty suspension weight distribution (far less likely), like lifting an unladen wheel.
Ive worked in used cars for a dealership for 10 years, buffing will make the glass "look" better but wont change the integrity. Glass pros can fill chips and stop cracks from spreading but no miracles when it come to wiper wear.Time for a new windshield
Thanks!
Only complaint I have with it is that the windshield is a little hard to see through when the sun is low.
Those scratches can make windshield wipers operate less efficiently. So I would car wax the windshield. Those tiny scratches are filled with wax making the wipers operate without streaks recreated by those scratches.
But I have never had a windshield so damaged as to so seriously refract sunlight. The wax might fill those scratches - obstructing light that would otherwise be refracted by the imperfection. But there is no alternative to glass replacement if the glass is that scratched.
I worked for a guy once who killed a pedestrian. Low sun hitting his glass meant he did not see the pedestrian; ran him over with the truck. Too many scratches creating sun obstructed vision should not be ignored.
That happens to me at least once a week.
Let's not even count the number of hobos you kill per week
I scratch little lines on the front fender.
I scratch little lines on the front fender.
How many Census workers did you unemploy now that they have less people to go look for and count?
If they're unemployed, does that make them hobos?
If they're unemployed, does that make them hobos?
According to Limaugh, they were paid so much more by Obama that they no longer have to work. According to Limbaugh, that was stimulus money.
According to Limbaugh, it will be harder for you to become an Ace. I believe you will need ten hobos to become a double Ace.
Hobo stimulus. :lol2:
tw, you are too funny!
Driving While under Stimulus
Oh Hobo. Let me play my oboe
Let me drive like I was blind.
If I am distracted. A charge redacted
Then I have achieved murder without a crime.
Oh walker. I am a talker.
Let me drive my mobile cell.
If I hit right. And can take flight.
Then more notches and compacted swine.
I have a car issue.
When I start the engine, a fair amount of water suddenly drips out from underneath (say, 1/4 cup or so.) Almost underneath the driver's seat, but a little more towards the middle. It is definitely not dripping before the engine starts, and it is definitely water and not some other fluid. Over the next 30 seconds to a minute, it gradually stops. This happens every time I start the car, and only started maybe a week ago.
What's going on? And please tell me it is not an expensive thing to fix.
sounds to me like the condensation from the A/C is building up and pushed out when the engine starts. Is the A/C or fan ON when you start the car?
There is a little drain "hose" under the dash somewhere that is probably leaking because it came off or dryrotted or or or. I had it happen in my Nissan on the passenger side. It must have been accidentally kicked off at one point and cost a total of $0 to fix.
Yes, the A/C is always left on because it's a thousand degrees here. :) I knew condensation could drip, but I didn't realize it could build up in some reservoir. Is it something that really matters? Could I (make Mr. Clod) get under there and reattach an obvious hose, or is it a more internal thing?
It is probably (if this is what it is) very easy to fix and Mr. Clod should be able to do it no problem. If the male end where the hose connects is broken it could be another matter.
If the hose just got knocked off, its nothing more than slipping it back on.
I have a feeling one of my kids, when they were younger like yours, accidentally knocked it loose. Have him take a look and see where its dripping from when you start the car.
Oh and I won't do the need additional data, facts, info post yet. ;)
The cartalk guys also talk about that hose getting clogged and the reservoir overflowing.
So it's just water, right? If it leaks in the wrong place, will it even cause rust or mildew in a car in drought stricken arid Texas? You would think it would just evaporate quickly. Why fix it at all?
Keep a bottle to collect the water. You might need it later.
I've got a car question.
Rough idle.
The car is old. After it warms up from driving around, when I stop at a light and push in the clutch, or shift out of gear, it goes into an idle where it's pretty rough. The CDs in the door pocket start to rattle against each other. The hard roof liner starts to vibrate against the roof. If I apply a little pressure to the accelerator and ever so slightly rev the engine, the vibrations and roughness go away. It does not have a rough idle when cold. (I understand the computer sends different signals to the engine when it is still cold than when it has warmed up and the fuel mixture is different then.) It is not rough when driving. This has been going on for a couple months.
How to improve? We had new spark plugs and wires (and presumably distributor cap?) replaced about 30K miles ago as part of a tune up done then, so they should still be good.
It has 115K miles now. We did that first (only) tune up at about 85K.
I could just go replacing stuff, but would like to know where a good place to start is. I was thinking fuel injectors. We've never done anything with those. Are clogged fuel injectors likely to cause symptoms only during idle?
Oh, this is a 1996 Geo Prizm LSI with the 1.6 liter engine and manual transmission. 115K miles. Starts fine. Drives fine. But idle is rough. Never stalls.
OH! OH! Is the check engine light on?
I've got a car question.
Rough idle. ... After it warms up from driving around ... it goes into an idle where it's pretty rough. ... If I apply a little pressure to the accelerator and ever so slightly rev the engine, the vibrations and roughness go away. It does not have a rough idle when cold. ... It is not rough when driving. This has been going on for a couple months.
That's an unusual combination of symptoms; but, I've experienced something like it. In my case, I noticed that it initially occurred during periods of high humidity and was exacerbated by cold-wet weather. It was a minor distraction that I put off having checked out for a few months until the condition began rapidly deteriorating to nearly disabling the vehicle. It turned out to be a faulty oxygen sensor which I had replaced under warranty.
I've got a car question.
Rough idle.
The car is old. After it warms up from driving around, when I stop at a light and push in the clutch, or shift out of gear, it goes into an idle where it's pretty rough. The CDs in the door pocket start to rattle against each other. The hard roof liner starts to vibrate against the roof. If I apply a little pressure to the accelerator and ever so slightly rev the engine, the vibrations and roughness go away. It does not have a rough idle when cold. (I understand the computer sends different signals to the engine when it is still cold than when it has warmed up and the fuel mixture is different then.) It is not rough when driving. This has been going on for a couple months.
How to improve? We had new spark plugs and wires (and presumably distributor cap?) replaced about 30K miles ago as part of a tune up done then, so they should still be good.
It has 115K miles now. We did that first (only) tune up at about 85K.
I could just go replacing stuff, but would like to know where a good place to start is. I was thinking fuel injectors. We've never done anything with those. Are clogged fuel injectors likely to cause symptoms only during idle?
Oh, this is a 1996 Geo Prizm LSI with the 1.6 liter engine and manual transmission. 115K miles. Starts fine. Drives fine. But idle is rough. Never stalls.
Glatt, good news! That is a super easy fix.
Look to the right of the steering wheel for one of these. Twist the knob on the Left CLOCKWISE until the sound of the rough idling disappears. If you turn it all the way clockwise and you still hear the rough idle you may need to get a new one.
that's the check engine light override knob, isn't it?
Yep. And the better ones go all the way up to 11...
Wise guys. :D
So I checked the factory manual. I hadn't been able to find the right section before. But I found it. They list 26 separate things to check for a rough idle like mine. The O2 sensor is one of them. This could take a while.
By the way, is that engine fuel-injected, or carbureted? If the latter, maybe it's a jetting issue.
Glatt, good news! That is a super easy fix.
Look to the right of the steering wheel for one of these. Twist the knob on the Left CLOCKWISE until the sound of the rough idling disappears. If you turn it all the way clockwise and you still hear the rough idle you may need to get a new one.
When we were on our last day of driving to Yellowstone, we were about 20 miles out in farmland when a loud hiss arose form the front of the car, Oh Crap!, is it overheating? gauge says not, just the AC wheezing ? then it dies away, weird we drive on.
About ten minutes later it starts again getting louder and softer, sounds right at the front, like it's coming out of the heating vents. After moving my hands around covering things up to see what changes the sound I notice the radio is on, but there are no stations out there it's just the static coming and going
:blush:
It is fuel injected.
So in addition to hooking it up to a code reader, the shop manual says to:
- check oxygen sensor
- check throttle position sensor
- check engine coolant temperature sensor
- check MAP sensor
- check if problem occurs when engine is running Rich or Lean (I think it's lean when it's hot, which it is)
- check evaporative emission (EVAP) control system
- check fuel injectors
- check fuel pressure
- check ignition voltage output
- check spark plugs
- check spark plug cables
- check ignition timing
- check for vacuum leaks
- check the ECM/PCM grounds
- check ECM/PCM for A/C signal
- check EGR
- check battery cables
- check A/C refrigerant pressure
- check PCV valve
- check for broken engine mounts
- check valve timing
- check low compression
- check bent push rods
- check worn rocker arms
- check valve springs
- check camshaft lobes
Holy crap. I can rule out about half this stuff, because it doesn't make the metal clanking sound of worn valves or bent push rods or anything like that. And it has nothing to do with the A/C being turned on. And we just replaced the PCV valve. The spark plugs and distributor cap are not as new as I thought they were (they are about 30K miles old,) but the cables look good and clean on the outside.
It is fuel injected.
So in addition to hooking it up to a code reader, the shop manual says to: ...
Many of those items need not be checked either because they should never fail in the life of the car, or would be obvious from sound and observation.
Never need replacement include spark plugs and wires, rotor and cap, and PCV valve.
Would be obvious for other reasons include: fuel pressure, fuel injectors, battery cables, broken engine mount, and valve timing and those other related entries including camshaft lobes.
These entries should result in a check engine code: oxygen sensor, throttle position, coolant temperature sensor, MAP, most injector problems and low fuel pump pressure, EVAP problem (that will even detect a missing gas cap), ignition timing, and EGR.
I have no idea why refrigerant pressure is on the list unless they are discussing a mechanic who over pressurized the system.
That should seriously shorten a list of top suspects. Having said that, I don't know how 'good' your car's diagnostic software is. But being 1996 or later means a diagnosis is much easier due to that computer diagnostic port.
Have you ever read "Shop class as Soul craft" tw? You might benefit from it. It's about an ivy league college graduate (probably an mba to boot) who's taken up motorcycle repair. He finds a sublime pleasure in diagnosing the trouble in a poorly running machine, kind of like glatt's situation.
I ask if you've read it because there's a thought expressed in the book I think you'd appreciate. The author says that there's an absoluteness to the machine. That despite the theoretical, the documented, the machine doesn't really care. That it is up to the mechanic to observe, to listen to what the machine is telling him, and then respond accordingly, even if it is contrary to "the book".
When you say things like "spark plugs and wires and caps and rotors never need replacement" I just roll my eyes. I don't know anybody who has any actual wrench time that would say such a thing. No one who has spent time actually working on cars would ever entertain such a ridiculous notion in a situation like this. Maybe, maybe in a theoretical discussion of what a perfect world would be like, etc. But come on. That's not what glatt's dealing with. His car's running roughly in some conditions and it is completely reasonable to think that a misfiring cylinder because of a bad spark plug could cause this, as an example.
If you're just ranting, rant on brother. But you're not giving much practical help here with proclamations like that.
My main point is when you say "should never fail" I have to edit it to read "probably isn't the cause of your problem, but ...". It irritates me.
My wife reports that it's not doing the rough idle today. A couple days ago she filled the tank with the super premium gas because she had an 80cents off code from the grocery store. Hmm. Don't know if those two facts are related. I need to continue the observations.
The author says that there's an absoluteness to the machine. That despite the theoretical, the documented, the machine doesn't really care. That it is up to the mechanic to observe, to listen to what the machine is telling him, and then respond accordingly, even if it is contrary to "the book".
So stop reading so much theory. Learn from those who were edcuatd by reality. So many cars (even in the 1960s) were fixed by learning this stuff the hard way. In the 1960s (due to bad designs), spark plugs and wires had to be replaced constantly. When one who mocks your theoretically trained author, instead, designed an installed an electronic ignition in a 1960s car, then spark plugs never needed changing. How many engine systems did your guru design? How often did he also trace failures back to the source by learning from the hardware?
So many religiously trained mechanics preach, "But the car has a heart". Many are recommending tune ups and wheel alignment only because it increases their income. All cars (even GM) no longer have nor need tune ups. But then I a stating this because I not only know this stuff by doing it. But also designed parts or traced failures to defective designs.
Any car that needs spark plugs, wires, or cap in 200,000 miles was probably something designed by a bean counter in GM. Even GMs parts can not longer fail as frequently as they once did only due to Federal laws.
Listed where the more likely suspects. Only those being scammed by a mechanic need replace spark plugs, wires, or cap even in 100,000 miles. What was once required every 5000 miles or three months was obsoleted decades ago when EPA rules made current technology required in all cars.
TW, I think you need to read Big V's post again.
It may well be that spark plugs should never need replacing, that's the theory. Each car is it's own independent reality, and we've got to allow for the fact that quality control was pared back by MBA managers to save money, and that the car was built and serviced by humans. You know, those frail, irrational bags of mostly water?
It's like with the paperless office discussion. You're not allowing sufficiently for human fallibility.
It may well be that spark plugs should never need replacing, that's the theory. Each car is it's own independent reality,
Last time I looked, Limbaugh was being sponsored by spark plug companies. Sandusky recently said to take a defensive position. Replug annually to avoid infant mortality.
The scheduled maintenance for this car makes no mention of changing the spark plugs, but for cars that routinely tow, it says you should change the plugs every 30k miles.
I had read several years ago that plugs today are really good, and that you could go 100k miles on them (or more) but they get to be very difficult to remove if you wait that long to switch them out, so consider switching them out sooner than that.
TW, I think you need to read Big V's post again.
It may well be that spark plugs should never need replacing, that's the theory. Each car is it's own independent reality, and we've got to allow for the fact that quality control was pared back by MBA managers to save money, and that the car was built and serviced by humans. You know, those frail, irrational bags of mostly water?
It's like with the paperless office discussion. You're not allowing sufficiently for human fallibility.
Did the outside temp change? My money is on the O2 sensor.
We should all bet on it, and whoever is right gets to pay for the repairs.
But you said your money was on the O2 sensor.
Oh, maybe I should have rephrased that. :)
We should all bet on it, and whoever is right gets to pay for the repairs.
:idea:
Loose wire.
:)
I took it to Track Auto or Autozone or one of those places. And they hooked it up to the code reader, and there were no codes found.
I guess that means the oxygen sensor is OK?
I guess that means the oxygen sensor is OK?
Most likely, yes. But again, described was how to make some code reported. Some codes will not be reported unless a defect is seen in multiple and consecutive restarts.
Most O2 sensor failures I have seen get reported by diagnostics long before it causes engine roughness or lower gasoline mileage. And again, gasoline mileage is an important parameter in locating these intermittent type problems. Some defects will cause mileage reduction. Others will not.
I took it to Track Auto or Autozone or one of those places. And they hooked it up to the code reader, and there were no codes found.
I guess that means the oxygen sensor is OK?
Was it exhibiting the symptoms at the time the test was taken?
Yes and no. It had been rough idling moments before, but it was turned off for the code reading. Key was only turned part way and engine was not running.
Ok, well then I guess the O2 sensor is not indicating an error.
NO readings means that the problem is coming from some source(s) in the system that don't report back to the computer. Things like ZenGum's "loose wire".
glatt, how much do you know about a 4 cylinder internal combustion engine like the one you've got? I don't want to talk down to you, I'll just think out loud.
When it's running right, two cylinders fire at the same time, like 1 and 4, then two strokes later cylinders 2 and 3 fire (a common firing sequence). Since everything is balanced mass wise and thrust wise, it feels smooth. As soon as something in that little set of sequences doesn't happen (and there's a missing piece, not an extra piece. No phantom fifth cylinder appears to unbalance the weight or the firing. No. Something's NOT happening, like one cylinder not firing unbalancing the engine, manifesting as rough idle). So, what could cause a cylinder to periodically not fire/misfire?
The holy trinity of internal combustion is fuel + air + fire. If you're missing one or more of those you're screwed. And they have to be delivered in precise amounts and precise proportions and at precise times. What could cause an interruption to any of these?
Let's subtract unlikely candidates and see what's left. It's unlikely that you're not getting air to a cylinder. A dirty air filter would restrict airflow to all the cylinders, not just to some, so... I can't think of another likely cause for "missing air" that wouldn't also have some other much more dramatic symptoms. I think your engine's getting the right amount of air.
And, that air is being delivered continuously and at pretty constant pressure and temperature, so it can be treated as a constant, putting the responsibility for fuel/air mixture proportions on the fuel side. You said the engine is fuel injected. Ok, what controls the injection? If it is mechanical injection, it's a masterful clockwork designed to figure out how much fuel to squirt, but your car almost certainly has electronic fuel injection. What electronic fuel injection is about is a system of sensors like throttle position, speed, gear, emissions, etc etc that help the computer decide how much fuel is needed to meet these conditions.
I had an old Buick LeSabre that would sometimes give me grief. It turned out there was a (gah, I hesitate to tell) design weakness that involved the air mass sensor (the MAP sensor in your car). Sometimes the car ran like shit, or wouldn't start at all. I learned to open the hood, and give the plastic intake snorkel a sharp whack, close the hood and carry on, problem solved. It turns out that the sensor was used to determine how much actual air was moving through the engine by putting two different magical detectors very close together, kind of like the rubber hoses you saw in gas stations years ago that rang the bell ding ding when you drove over them? Well the modern version in traffic surveys has a pair of these hoses across the roadway and it can calculate the speed of the cars by measuring the length of time between the tire touches on the two lines. Well this sensor worked like that but the wires were so close together that when a tiny piece of crud was sucked into the airstream, if it caught on the sensor part of the wires (strung directly through the airstream, just like the traffic sensor) it could cause erroneous readings. A smack on the housing usually dislodged the minute particle of junk, the sensor was then able to read the amount of air, and reported back to the main computer and the rest of the calculations would result in the right amount of fuel to be injected; life was good.
Back to your car, something could be interfering with a perfectly good sensor, like some crud on the sensor, and causing it to report bad values, with the downstream effect of a roughness because the cylinder's not getting the right amount of fuel. But which sensor when the computer check says none is ... really tough and expensive.
Maybe you have a tiny piece of dirt in one of the injectors. I have an old house and a very low flow showerhead (2.5 gal / min). Sometimes some rust/crap from the inside of the pipes flakes off and makes it's way to the showerhead. This clogs it and the flow is reduced even further. Not good. I take the showerhead off, clean out the crud, reassemble and carry on. Now, the tub faucet is on the same damn pipes, but I never have this trouble there. The flow/current/pressure (whatever) is just so high that if it even happens, I never notice it. Back to your car. Maybe you have a little piece of dirt in one of the injectors and at idle, low speed, low pressure the dirt can interfere with the squirt of gas, causing a misfire. At road speed, you don't notice because you're pushing a lot more fuel through (like my tub faucet), so problem isn't noticed. To me, this is plausible. Fixing something like this can be pretty hard. The injectors aren't really.... repairable. They're replaceable, but could be bux. The orifice is super tiny, imagine the size of hole that produces a vapor or fine mist, like a perfume mister or spray can. Psssshhhhht. or more like psht psht psht psht psht 800/2 times per minute. You could try commercial injector cleaners that you pour in the gas tank.
What else could cause irregular fuel delivery. It is also plausible that the whole engine is being a little starved for fuel under low pressure situations like this, as might happen if the main fuel filter was moderately dirty. Have you checked your fuel filter? This can be an easy and cheap fix with little downside. Once more, at road speed, this would be less obvious at the higher pressures.
Fuel...fuel... a physical restriction, or bad instructions to cause it to erroneously deliver the wrong amount of fuel... those are all the situations I can think of at this time for fuel. Air, check. Fuel, check. Now fire.
--to be continued--
--continued--
For fire, you need the spark plug to go zap at precisely the right time. Also you need a big fat spark. Unlike fuel and air, this one is not "quantity" dependent so much, it's really hard to have too big of a spark. You can have too weak of a spark, and no spark is also bad, but there isn't a proportion "rule" unlike fuel and air. But it is definitely timing sensitive. So we're looking for possible faults that could cause a weak spark or a mistimed spark. Ok.
Weak spark could be caused by some deteriorating connection or component working your way backward from the electrodes on the plug to the connector at the top of the plug, to the plug boot, plug wire, other end of the plug wire, to the coil (or whatever is generating the giant pulse of electricity) to the ? and at this point it varies a lot depending on what kind of ignition system you have. This is the same question as what kind of fuel injection, mechanical or electronic. If it is electronic, you only have the ECM (electronic control module(s)) to rely on upstream of the plug wires. There's nothing you can do in there except replace and only on the "instructions" of the code reader (for us shade tree mechanics). You're not getting a code there, so I don't have anything to point to the electronic ignition system, sorry. If you have a mechanical ignition system with a distributor cap (the cap that "distributes" the electrical pulses by rapidly changing which cylinder has a complete electrical circuit) that could be a point of intermittent failure. It also comes with a rotor, same possible fault. There could be other pieces there that are weak at low speed (like points or a condenser). But I don't know if you have a mechanical ignition system. I have a 1996 car (VW Golf) and it has electronic fuel injection and a mechanical ignition system. I have had trouble with the ignition system before.
Trouble's not really fair, it simply needed some regular maintenance which meant replacing some of the components, like the cap and rotor. This was the best $25 I put into the car that whole freakin year. Your car? I can't say. Do you know if you have mechanical or electronic ignition?
Other causes of weak spark could be degraded or damaged plug wires. You could have a bad plug. They operate in severely harsh environments--think Mount Doom--and need to keep performing a very difficult electrical stunt, ionizing air to make a conductive path (fancy ass way of saying spark) a kabillion times. In shitty atmosphere. Sometimes that crud accumulates on the plug and interferes with the spark. Yeah, really. This is an easy thing to check, assuming you can actually get to the plugs and you have a ratchet and an extension and a plug socket. footfootfoot's car doesn't qualify here, since he can't get to all the plugs. He/you certainly could check the ones you can reach though, and if you see one that's bad, replace it. Check them all if you can. There are pics online somewhere I'm sure that show you in living color what the electrode end of a plug in good condition looks like AND what a plug in poor condition looks like. There will be lots of different "bad plug" pictures, since there are lots of reasons why a plug could go bad and be the source of bad symptoms. You can look them up. If you can't find them, report back, we'll find some for you.
So that's weak spark. What about absent spark? That's all the same, just weak to the level of zero. Fine. Oh, just thought that the coil could be weak, that's the part that generates the high voltage needed for a spark. It's like a transformer in your system.
What about mistimed spark? This is less likely, though not exotically rare. You could have a situation where the electricity that would have been your spark is leaking out before it gets to the plug. Like if a plug wire has a fault in the insulation and the spark is grounding out to the engine before it reaches the cylinder. One way to check for this would be to open the hood and look at the engine when it's displaying the symptom of roughness, but do it in a very dark environment. The idea is to have the fugitive spark reveal itself in the darkness. Doable.
Timing... thinking... A car that is mistimed could have a rough idle. What do you know about the car's timing? Have you checked it? Have you changed it? This isn't something likely to change on its own (possible, but pretty unlikely). If *you* have mucked with it or some other mechanic, it is possible that it's been changed from "best" to something less than best. I don't know how else your engine would miss a spark or mistime a spark.
Having thought out loud, it seems the most likely piece is a fuel delivery problem, junk in injector or fuel filter. Next and close behind would be an ignition fault. If it was my car, I'd do these things in this order until I found a likely problem.
1 -- visually check all the ignition wires. disconnect and reseat all these connections. this is free.
2 -- pull the plugs, check them. fouled? cracked? worn? beautiful?
3 -- replace fuel filter.
4 -- run a bottle or three of injector cleaner super duper turbo in a jug or whatever that crap is called through the car a full tank of gas at a time.
5 -- run the car on the TOP HALF of the fuel tank for a while. this probably should be item 1.5 or even item zero.
Tha's a good start. I'm interested to see what happens here glatt. Keep us posted please.
Wow, that's a lot of thought you put in there.
We had the timing belt replaced at the urging of a mechanic a few years ago, and after that happened, I was sure to pay attention to the performance of the engine. I don't remember any changes in performance overnight, so I think they did it right. These problems have been gradual, and I've just noticed it recently because it's reached a certain threshold of being annoying.
We also replaced the fuel filter a couple years ago too at the recommendation of a mechanic. Certainly long enough ago that it could be messed up in the meantime.
I'm leaning towards this engine just being old and dirty as being the most likely culprit, but I'm going to follow your ideas. When I get some time and daylight.
I learned to open the hood, and give the plastic intake snorkel a sharp whack, close the hood and carry on, problem solved.
I love it when you can fix a machine by thumping it. Very primal. RAWR! Og mad! Og Smash! [thwack ... vroom!!] Bwahahaha!
Oh, and as well as the above ... you
are using the recommended grade of gas, aren't you?
I love it when you can fix a machine by thumping it. Very primal. RAWR! Og mad! Og Smash! [thwack ... vroom!!] Bwahahaha!
the technical term is "percussive maintenance". It is very satisfying no matter how effective it is.
Oh, and as well as the above ... you are using the recommended grade of gas, aren't you?
gas grade is a measure of the octane in the fuel. Octane's role is to change the point at which the fuel / air mixture spontaneously combusts due to the heat from compression. You experience this as "knocking". It is most common when the engine is under a heavy load such as hard acceleration or towing or driving hard uphill. The mixture detonates before the piston reaches top dead center and/or the spark ignites an already lit combustion chamber and the result is a hard knocking sound. I've never heard of octane having much if anything to do with idle loads.
Good points, but I was thinking in terms of it not burning cleanly and being the source of gunk that could cause the problems you mention.
I've learned to check the very basics first. I've got part way through helping a friend remove the door skin from the back door before asking why he was doing this. The inside door handle wasn't working. Oh, does it have a child safety lock? A what? One of [click] these. :smack:
Then there was the friend who's car had broken down. After ten or fifteen minutes of experimenting, then calling the mechanic service, I noticed the fuel guage on E. :smack: Done this twice, about ten years apart. Same friend. :facepalm:
The car doesn't require high octane fuel.
Our regular corner gas station used to be a Texaco. But then Texaco pulled out of Virginia for some reason. So all the Texaco stations became "Liberty" stations. It's more of a discount gas station, but not significantly cheaper. I assumed it was just as good as Texaco. Around the same time, our grocery store began offering significant discounts on gas at Shell stations when you buy lots of groceries. We have a family of 4 and buy a lot of groceries. So most of our gas has been bought at a Shell, but in the last year or two, we have been buying some of our gas from this Liberty gas station on the corner. Maybe Liberty sells crap gas? I don't know. The dates roughly match the symptom dates.
My Beetle is supposed to use regular gas. I guess they've perfected engineering enough that we don't have to fall for the more expensive gas being better. I love that about my car. Not "we recommend the highest grade gas possible" but "USE REGULAR gas, or else."
It's written right inside the door to the gas hole.
So most of our gas has been bought at a Shell, but in the last year or two, we have been buying some of our gas from this Liberty gas station on the corner. Maybe Liberty sells crap gas? I don't know.
Read the many previous posts about this. Add maybe 26 cents per gallon to the price Liberty posts. Discount gasolines are the most expensive as explained previously.
To know more and to fix a rough idle, do gas mileage for every tank. Also posted previously. My experience says it takes two to four tanks of the good stuff to undo damage caused by discount gas.
And again, discount gasolines increase the nation's imports of foreign oil by 8% to 14% (numbers based upon my calculation; increased imports made obvious by your MPG numbers).
Major gasoline manufacturers are selling less gas because so many Americans even believed Saddam had WMDs - by ignoring facts and numbers. How many still do not learn from history? Notice how a majority are so easily decieved even by discount gasoline.
snip--
To know more and to fix a rough idle, do gas mileage for every tank. Also posted previously. My experience says it takes two to four tanks of the good stuff to undo damage caused by discount gas.
--snip
tw, how does recording the mileage the car gets per tank fix a rough idle?
It won't. He is trying to associate the two issues. Additional data points... Also, he is trying to see if the "good stuff " is working - maybe.
tw, how does recording the mileage the car gets per tank fix a rough idle?
A solution only exists when the problem is first defined. Some of those suggestions cause significant mileage decreases. Others (ie oxygen sensor) do not. Just one of many reasons why mileage numbers are important for solutions. Better help means first providing better information. Only relevant fact is roughness in idle. Nothing else identifies meat necessary for a solution.
Random fact:
My subaru *can* run on 91 octane, but the owner's book says to put in a bottle of fuel system cleaner every 6,250 kms (half of a service interval).
I couldn't find any in shops so I rang the Subi dealer. They said "yeah we stock it, but we don't recommend it, just run your car on 95 octane, it will keep it cleaner".
These guys could make money selling me this stuff, so for once I believe them.
So I was wondering if using El Cheapo gas might be dirtying up the system and causing these symptoms. Just checking the basics.
Wait - there is fuel in it, isn't there? ;)
Generic green beans are the same as the brand green beans, generic Wheaties are just as good as real Wheaties, I hear them cry. BS, I say.
Yet there is 'cheap' gas? Gas is gas is gas.
You're all eating a pile of hooky.
I think you need to check your tire pressure. When my tire pressure gets low it decreases my gas mileage. In fact, when my gas mileage is lower than I expect I always check my tire pressure.
Tire pressure is causing a rough idle now?
It's always a good idea to check tire pressure. The car was pulling slightly to one side a while ago, and I inflated the tires to the proper pressure. It fixed that. I go in spurts when it comes to car maintenance. It's probably been a couple of months since I checked the tire pressure. Couldn't hurt to do it again. I suggest all of you go check your tire pressure this week.
Car maintenance - it's complicated!
It's not so complicated, but it's a pain in the ass.
tw[COLOR="White"]
Read? I only know how to write.
Join Date: Jan 2001
Posts: 7,948
Quote:
Originally Posted by BigV View Post
tw, how does recording the mileage the car gets per tank fix a rough idle?
A solution only exists when the problem is first defined. Some of those suggestions cause significant mileage decreases. Others (ie oxygen sensor) do not. Just one of many reasons why mileage numbers are important for solutions. Better help means first providing better information. Only relevant fact is roughness in idle. Nothing else identifies meat necessary for a solution.
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Unread 11-15-2011, 10:51 PM #96
ZenGum
Doctor Wtf
Join Date: Oct 2007
Location: Badelaide, Baustralia
Posts: 8,932
[/COLOR]
Random fact
Ah. Now I get it. I had to stop reading between the lines.
tw
Read? I only know how to write.
yeh, after that ... (shrug)
Quote:
tw
Read? I only know how to write.
Join Date: Jan 2001
Posts: 7,948
Quote:
Originally Posted by BigV View Post
tw, how does recording the mileage the car gets per tank fix a rough idle?
A solution only exists when the problem is first defined. Some of those suggestions cause significant mileage decreases. Others (ie oxygen sensor) do not. Just one of many reasons why mileage numbers are important for solutions. Better help means first providing better information. Only relevant fact is roughness in idle. Nothing else identifies meat necessary for a solution.
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Unread 11-15-2011, 10:51 PM #96
ZenGum
Doctor Wtf
Join Date: Oct 2007
Location: Badelaide, Baustralia
Posts: 8,932
Random fact
Ah. Now I get it. I had to stop reading between the lines.
Find a different target, fellas.
tw tries to participate, and had been making some great funnies lately, but it always seems acceptable to be shitty to him. Why is that?
Anyway, the highlighted text makes no sense. tw doesn't live in Badelaide Baustralia.
I'm not being shitty to him. As for the joke, it went like this: tw (lots of lines of text followed by the words) random fact. I "got it" when I "read" "tw random fact", and not the stuff between those lines. It's a reference to his earlier post where he said to fix a rough idle, measure your gas mileage. That's nonsense.
I am really not being shitty to him, I'd love to solve this rough idling problem glatt's car has. I don't know everything there is about cars, and I love to learn new stuff. But unless tw has some magic trick he's still hiding, I don't see how his explanations achieve the desired result. If they do, that's freakin awesome because 1 -- problem solved and 2 -- I learn a new trick. If they don't, well, ok, fine, I already have a bunch of tricks that don't work.
I want him to explain his idea and show how it works. That's the beauty of working on machines (as I tried to explain several posts before) that machines don't need or are even susceptible to persuasion. I don't want to be persuaded that measuring the gas mileage will fix a rough idle, I want to be *shown how*. Maybe I can understand it, maybe not. But I haven't seen any explanation yet.
I was poking fun at tw's answers because they're freakin random.
I guess I'm overly sensitive on tw's behalf.
Sorry, and carry on.
I am really not being shitty to him, I'd love to solve this rough idling problem glatt's car has. I don't know everything there is about cars, and I love to learn new stuff. But unless tw has some magic trick he's still hiding, I don't see how his explanations achieve the desired result.
That is the point. You do not understand the relevance. Do not understand how that information results in solutions.
Solve problems in two steps. First collect facts. Much later solve the problem. Some of that stuff posted fix a problem without first determining what is wrong is called shotgunning. Could even exponentially complicate his problem. Those was some of the most random and irrelevant wild speculation I have read in a long time. Any mechanic that did that would have been quickly unemployed. You should have been mocked for those consecutive and irrelevant recommendations. But then making all those mistakes is how we eventually learn. I just ignored them suspecting that glatt also would probably be doing same.
Embarrassing was a claim that two cylinders fire simultaneously. And a few other bogus claims. Each cylinder fires separately. You should have known that since it was taught even in primary school science. No reason to mention that until now that you decided to entertain your ego. I was not going to say anything then. But now you need to learn some humility. Big time.
We have a list of suspects from the shop manual. And a few others not on that list. Facts such as diagnostic codes, information collected by a portable computer from the dealer, and gasoline mileage all provide relevant information. Facts to significantly reduce a list of suspects to but a few. Even the fact that roughness did not correspond to an engine code was useful information.
Also important are conditions that cause or co-exist when roughness does and does not exist. Whereas tire pressure likely is not relevant, it is still a change that should known. Never short the help of a change only because you consider it random or irrelevant.
Use the oxygen sensor as an example. Some assumed an oxygen sensor could cause rough idle. Why? An oxygen sensor is mostly about operation at high speed; not at idle. An oxygen sensor (in most designs) has no influence on how idle works. Why then did someone suspect an oxygen sensor? An example of implementing a solution long before a defect was even defined.
Gasoline mileage goes a long way to exonerating many suspects. But not everyone would understand that for a same reason why some might automatically suspect an oxygen sensor.
Another example was recommended. Full to the floorboard acceleration repeated after each engine restart. So that diagnostic codes might report some other defects. It should have been done especially when one has no idea what that will discover. What was to you random was actually targeting specific suspects.
You have no idea why gasoline mileage numbers were important. Numbers more useful had those numbers been taken when the car was running better. Numbers that would have even said more if taken for a tank of Liberty and another tank of Shell.
Moving on. Another explained what high octane gas is. It is not cleaner or better. High octane does not burn out crud. It is only different. Some brands include additives that make other differences.
For example, Mobil once contained high detergent additives. Therefore gas was cleaner? No deposits? Nope. High detergent levels in Mobil caused increased carbon deposits on valve stems.
Same applies to high octane. High octane can increase engine wear and failure on some parts. The word high does not mean better (except at the end of the day in a room with a towel covering that hole underneath the door).
I push in the trip odometer every time I fill the tank, and it's usually around 280 miles if I've been driving around town and 310 miles or so if I've been on the highway for the entire tank. I haven't noticed a huge change in those numbers. How big would the change in mpg have to be to be significant? I haven't noticed a change, so I figure the mileage hasn't changed by more than 5%, if it has changed at all. I think it has stayed the same.
How big would the change in mpg have to be to be significant? I haven't noticed a change, so I figure the mileage hasn't changed by more than 5%, if it has changed at all. I think it has stayed the same.
The difference between crap Liberty gas and Shell gas would (for example) result in maybe an 8% difference without any noticeable change in idle smoothness. If your numbers are as reported, then Liberty gas should have caused a noticeable mileage difference. The fact that you saw no difference is troubling.
In another event, a tank of Mobil destroyed my fuel injectors. I knew something was wrong due to a slight roughness in idle. But the resulting mileage change was from 32 MPG to about 27 MPG in that tank. And 24 MPG in the next tank. (Honda replaced those injectors for free). In that case, diagnostics never reported a problem.
In another case, a problem with an EGR valve kept causing a check engine light. No mileage change. Symptoms that helped me trace the problem to a hard and not easily diagnosed problem. (BTW, EGR valve is not connected to the idle system; so did not affect idle. And that failure was unique so as to not affect gas mileage.)
Examples of different failures that do and do not result in mileage changes. And that isolated the problem quickly to a shorter list of suspects.
Assuming that 5% coincided with road conditions (heavy traffic, summer open road driving, etc), then is we can assume you have a problem traceable to the idle system and that does not affect the other 'normal operation' system.
BTW, remember Cloud's problem. That was also traceable to the idle system and that would not cause mileage changes. That mechanic had one clear advantage. The Civic's diagnostic system pointed exactly to the defect - which that mechanic refused to address. An example of why some people just refuse to learn good diagnostic procedure.
Now, with Shell, what is happening? What are the latest symptoms?
Well, the roughness seems to be not so bad the last week or so, but I'm not sure. The roof used to buzz from the vibration and that's not happening recently, but there is still some roughness in the idle after it warms up. You can feel it in the steering wheel and the cds in the door pocket rattle. It still goes away when you give it some gas.
I have old records of the mileage from when this car was new and I was better at tracking that stuff, and I can compare that to the mileage the next time I fill the tank, but keep in mind that gas didn't have ethanol in it back then, so it would be comparing apples to oranges.
Is it worth it to buy a bottle of fuel injector cleaner and dumping that in the tank? Would that harm anything other than a few wasted dollars?
Also keep in mind that we don't drive much. I take the subway to work, so it might be a couple weeks before we fill the tank again.
The roof used to buzz from the vibration and that's not happening recently, but there is still some roughness in the idle after it warms up. You can feel it in the steering wheel and the cds in the door pocket rattle. It still goes away when you give it some gas. ...
Is it worth it to buy a bottle of fuel injector cleaner and dumping that in the tank? Would that harm anything other than a few wasted dollars?
Is that a new symptom? Roughness was when warm; not when cold? Or is roughness same when engine is warm or cold at 1000 or 1200 RPM - the cold idle speed?
I would avoid even trying to fix anything. First establish some trends. You still have some Liberty gas in there. And you really do not have MPG numbers. Only mileage for some approximate gallons of gas.
Stated earlier: first get facts. Dumping that miracle fluid in only adds another variable; can create confusion. One step at a time. You describe something that is not serious. You can live with it for a few months until the problem makes itself obvious.
Or you can take a nuclear option. Spend more. Take it to the dealer. My preference is to learn from an anomaly that is minor - will not leave you stuck. Not just learn how a car works. But how to better diagnose any problem. A memorable moment in life is that "Aha-Ha" moment. When that solution is sudden, obvious, and appears to materialize from nowhere.
I would avoid that additive until current trends stabilize - ie enough tanks to accurately identify gas mileage or to see roughness stabilize – become predictable. Currently roughness is different at different engine temperatures? Or just at different idle RPMs?
That is the point. You do not understand the relevance. Do not understand how that information results in solutions.
right, RIGHT. Exactly. Now, at last, you understand my question. Of what possible relevance is gas mileage measurement fixing a rough idle?
Solve problems in two steps. First collect facts. Much later solve the problem.
You have some facts. You don't have all the facts. You'll never have all the facts until the problem's solved.
Some of that stuff posted fix a problem without first determining what is wrong is called shotgunning. Could even exponentially complicate his problem. Those was some of the most random and irrelevant wild speculation I have read in a long time.
No, it's not called shotgunning. It's called an iterative process, a process of elimination.
Any mechanic that did that would have been quickly unemployed. You should have been mocked for those consecutive and irrelevant recommendations.
Well, he's not taking it to a mechanic, he's asking us, asking me. I think a mechanic that did the things I suggested would be employed far longer than a mechanic that did the things you suggested. Just curious, what part of my recommendations do you consider irrelevant?
But then making all those mistakes is how we eventually learn. I just ignored them suspecting that glatt also would probably be doing same.
Embarrassing was a claim that two cylinders fire simultaneously.
Cite. An even firing sequence is pretty common, anything else is unusual for an inline four.
And a few other bogus claims.
Cite.
Each cylinder fires separately.
Cite.
You should have known that since it was taught even in primary school science. No reason to mention that until now that you decided to entertain your ego. I was not going to say anything then. But now you need to learn some humility. Big time.
Buddy, I've been sayin that from the beginning. If you have something to teach me, bring it on. To this point you have not been forthcoming. I've asked you and asked you for your explanations, only to be be met with silence and bloviation in equal measure. You have some mechanical explanations for what's happening here, I'm interested in learning them, humbly. I'm still waiting...
We have a list of suspects from the shop manual. And a few others not on that list. Facts such as diagnostic codes, information collected by a portable computer from the dealer, and gasoline mileage all provide relevant information. Facts to significantly reduce a list of suspects to but a few. Even the fact that roughness did not correspond to an engine code was useful information.
Sure. We have some facts, ok, I agree. Now what do you suggest to do with the facts you have?
Also important are conditions that cause or co-exist when roughness does and does not exist. Whereas tire pressure likely is not relevant, it is still a change that should known. Never short the help of a change only because you consider it random or irrelevant.
I short the help of a change (???) when it a distracting obfuscation. Like gas mileage. You do know that the gas mileage of his car when idling is zero, right?
Use the oxygen sensor as an example. Some assumed an oxygen sensor could cause rough idle. Why? An oxygen sensor is mostly about operation at high speed; not at idle. An oxygen sensor (in most designs) has no influence on how idle works. Why then did someone suspect an oxygen sensor? An example of implementing a solution long before a defect was even defined.
Gasoline mileage goes a long way to exonerating many suspects.
Really?? For a rough idle? HOW? How? That is my question, how does knowing the mileage fix the rough idle? It doesn't man. You might have posed a better question by asking how the mileage has changed. But even then you would have gotten a small range of answers, same, better, worse, LOTS better, LOTS worse, all over the place, stuff like that. But even knowing which of those answers was the "fact" leaves you with no suggestion as to what to *DO*.
But not everyone would understand that for a same reason why some might automatically suspect an oxygen sensor.
Another example was recommended. Full to the floorboard acceleration repeated after each engine restart. So that diagnostic codes might report some other defects. It should have been done especially when one has no idea what that will discover. What was to you random was actually targeting specific suspects.
You have no idea why gasoline mileage numbers were important.
If you do, please tell me.
Numbers more useful had those numbers been taken when the car was running better. Numbers that would have even said more if taken for a tank of Liberty and another tank of Shell.
Moving on. Another explained what high octane gas is. It is not cleaner or better. High octane does not burn out crud. It is only different. Some brands include additives that make other differences.
For example, Mobil once contained high detergent additives. Therefore gas was cleaner? No deposits? Nope. High detergent levels in Mobil caused increased carbon deposits on valve stems.
Same applies to high octane. High octane can increase engine wear and failure on some parts. The word high does not mean better (except at the end of the day in a room with a towel covering that hole underneath the door).
So, based on what facts we all know, what do you think could be the reason for the rough idle and what do you suggest to resolve that symptom?
No, it's not called shotgunning. It's called an iterative process, a process of elimination.
What was posted was classic shotgunning. As I said before, a major reason for fixing things is to learn. Eventually you may learn that those long posts were classic examples of shotgunning. You were even trying to fix things that were not relevant to his symptoms. Trying to fix things base upon "it might be this so do that". That is shotgunning.
Some of your suggestions would fix things not even relevant to the symptoms. Understandable because even some basic concepts, essential to auto repair, were unknown. A firing order for a four cylinder engine is typically 1, 3, 2, 4. Two cylinders do not fire simultaneously. That would cause imbalances. Explains many suggested actions that were irrelevant. Shotgunning often happens when underlying concepts are not first learned. Again, cylinders do not fire simultaneously.
what do you think could be the reason for the rough idle and what do you suggest to resolve that symptom?
Exactly the point. Once never cures symptoms. Symptoms are part of the process of identifying a defect. Fix defects; not symptoms. First identify the problem. Fixing comes much later. Shotgunning is suspecting and then fixing things when one has not a clue.
In an example, you asked how gas mileage fixes rough idle. Again, fixig comes later. Gas mileage is the process of first identifying the defect. Using gas mileage to fix roughness is an example of 'shotgunning'.
Based upon facts, a defect is not yet identified. A long list of suspects exist. Many might be eliminated with better knowledge, labor, or equipment. Ie. remove a suspect to test it on the bench. But that would take time, more posts, and sometimes creates new problems. Instead, use better knowledge, for example, to know an O2 sensor is an unlikely suspect (based upon symptoms provided).
No rush. The car still works. Plenty of time to identify the problem.
Facts provided a reduced suspect list - posted earlier. Still too many. Listed was how to obtain more facts since even mileage numbers could reduce that list. Mileage numbers are still too subjective.
However if you know more, then define what will identify or exonerate each suspect. The list is there. If you know more, then detail how to identify the defect from that suspect list.
Other relevant questions were asked such as behavior at various RPMs and temperatures, changes after Liberty gas has been fully displaced by regular Shell, operation so that engine diagnostics can see some problems, and using an onboard computer to monitor engine parameters when roughness does and does not happen.
In thinking back, I don't remember. Another of many still unanswered questions. Were spark plugs and wires changed a few thousand miles before this roughness started?
So, based on what facts we all know, what do you think could be the reason for the rough idle and what do you suggest to resolve that symptom?
Trying to get a straight answer from TW is like trying to nail jelly to a tree, innit?
Someone drove the car until the gas was very low, and/or
the gas cap was not put on tightly so the check engine light came on.
Full tank of fresh gas + tight cap + running engine 30+ minutes => light goes out = problem solved. :rolleyes:
.
I'm tired of arguing with you tw.
I misspoke about two cylinders firing at the same time. What I was trying to communicate is that two cylinders are UP and two cylinders are DOWN at the same time. One of the UP cylinders is on the compression/power stroke and the other UP cylinder is on the exhaust/intake stroke. My point is still valid and that is if there's something that causes one of the cylinders to misfire, that will cause the engine to be unbalanced. This in turn is felt as a vibration, a roughness.
As for the rest... we just disagree on a couple of things. What you call shotgunning, I call eliminating possible problems. What you call gathering information, I call sitting on your thumbs. What you call no rush, I call no clue. That's fine. You seem to want more and more information until you know what to do, and then you want to spend one bullet only to kill the problem. That is definitely one way to fix problems. It's not the only way, and in my opinion it is not a very effective way. But it's your way and that's cool.
The rest of your crap, whatever dude.
I'm tired of arguing with you tw.
Why are your arguing? Did you always argue with your algebra teacher when concepts were too hard?
What you call eliminating problems is classic shotgunning. No way around reality. Since you never learned good diagnostic procedure means it must be wrong?
Many never learn this stuff. Assume it is too complex; therefore must be wrong. Get angry and become argumentative rather than learn. No argument exist. Just facts. Fatigue is you fighting to avoid learning. Only you can choose to learn or remain argumentative. Well proven reality, for some reason, distresses you. As if learning this stuff would somehow hurt you.
OK, so how an engine works was completely contrary to what you accidentally posted. Fine. And still irrelevant to the topic - rough idle.
glatt has options (and outstanding questions) to find an actual defect. Or to whittle that list down to but a few suspects. Apparently you want him to keep replacing parts as a mechanic did to Cloud - four times and how many $hundreds? A new mechanic who did not shotgun meant Cloud's defect was eliminated the first time. He followed the evidence. A concept also defined in Japan as “work smarter; not harder”.
Good diagnostic procedure finds a defect before wildly replacing good parts on speculation. Follow the evidence. They even made TV shows based on the concept.
Cloud's defect was eliminated the first time.
Actually the fifth. The first mechanic had already tried four things.
A concept also defined in Japan as “work smarter; not harder”.
Um, isn't that actually the min-max rule?
jus sayin.
Actually the fifth. The first mechanic had already tried four things.
A second mechanic was forced to testify before the grand jury?
no, that was the gas station attendant that noticed the wipers malfunctioning.
I have changed my mind. I'll argue some more.
About cars, it's clear I have more experience and skill than you have when it comes to working on them. About language, it's clear I have more skill at getting my ideas across, I am more articulate and I can better answer direct questions.
But when it comes to just talking nonsense, you surpass me. There is no argument there. Your use of language is somewhat stilted. You make the wildest assertions and assumptions. You put words in people's mouths. Your failure or refusal to answer direct, civil questions makes you impossible to work with. I don't know why you do that, but it's not really important. You either don't know, or you do know, but you don't say. Your bluster and evasion, while entertaining, is unhelpful at solving the question at hand. You post bullshit, get called on the bullshit, and ignore it. I would too, had I posted the crap you posted.
I'll give you another chance. What you do with it will be interesting. Will you demonstrate your knowledge and civility and answer the question? Or will you dodge it again, demonstrating your ignorance and hostility? Either way, I'm looking forward to your next post.
tw: Will you please explain how measuring gas mileage will fix a rough idle, as
you asserted in post #92?
TW, what outstanding questions? You mentioned hooking it up to a computer and revving it. I don't have the tools to do that. Was there something else?
I drove it a short distance this morning, and it never had a chance to warm up. The idle was fine. But since it's only a problem when it's warmed up, it behaved as expected.
I think the problem is caused by the flint on one of the spark plugs needing replacing.
No, no, no...the flint stones didn't use fuel or spark plugs or oil drums. They just ran along with their feet hanging out of the hole in the bottom of the car.
Also important are conditions that cause or co-exist when roughness does and does not exist.
Many examples were requested. Other patterns may exist but would only be apparent to you.
I haven't noticed a change, so I figure the mileage hasn't changed by more than 5%, if it has changed at all. I think it has stayed the same.
Number must be provided. That was only what you feel. How many gallons (to at least a tenth of a gallon) per how many miles? And what were those MPG numbers back in better days?
Now, with Shell, what is happening? What are the latest symptoms?
I would avoid that additive until current trends stabilize - ie enough tanks to accurately identify gas mileage or to see roughness stabilize – become predictable. Currently roughness is different at different engine temperatures? Or just at different idle RPMs?
So what does it do when at 800 RPM? 1200 RPM?. When cold. When half warm. When hot at all those RPMs? Cold unfortunately means 800 RPM symptoms are not possible. Apparently it is still doing it hot. But at what temperature on the gauge does it start getting rough? Or does it only get rough when the high idle finally drops to 800 RPM.
Not yet stated is if you even have a tachometer on the dash - an example of information I was waiting for or had to assume was not relevant.
What other techniques were used or tried unsuccessfully to aggravate and diminish roughness? What parameter change when it becomes better or worse?
Previously discussed were the two separate systems. Idle and normal operation. How do symptoms change or exist in both modes?
Other relevant questions were asked such as behavior at various RPMs and temperatures, changes after Liberty gas has been fully displaced by regular Shell, operation so that engine diagnostics can see some problems, and using an onboard computer to monitor engine parameters when roughness does and does not happen.
The dealer connects an onboard computer. Or buy one for something like $150. However you must then learn the technology - which a dealer provides with his better computer for a fee. That onboard computer is how dealers find intermittents - should you need it fixed now. It is an option reserved for the future. But the option is how these type problems can be located.
Have you been flooring it after each restart as requested?
Another of many still unanswered questions. Were spark plugs and wires changed a few thousand miles before this roughness started?
More suggestions. While idling, put your ear near the exhaust. Listen. Does it run smooth? Is there a pattern or sound? How does this also change with the next tank of Shell? How does it change with cold and warm? Examples of details that might quickly identify a problem without hiring an expensive dealer mechanic.
So what else was changed in the few thousand miles before this happened. Change of gas. Change of spark plugs. Anything else. All are example of what was noted early:
Whereas tire pressure likely is not relevant, it is still a change that should known. Never short the help of a change only because you consider it random or irrelevant.
I am assuming this problem still exists. Because nothing said so definitively. Is it still as bad? Or has it diminished as implied in a later post or with another tank of Shell?
If the idle is rough, just sand it down until it's smooth.
Hey! I'm trying not to be abrasive here.
Fuck. Check engine light is on. Got the codes read at AutoZone, they say:
P0421 - Warm up catalyst system (RH) efficiency below threshold
P0431 - Warm up catalyst system (LH) efficiency below threshold
P0174 - Lean Air/Fuel ratio bank 2
I know it will not pass inspection with this issue. But I just passed in November, so I'm safe there for 11 more months. My question is, is this a dangerous thing to be driving around with, or can it hang out for a few months with no real problems other than continuing to degrade a catalytic converter that is probably going to need replacement either way? I have to drive this thing for about 10 hours of holiday travel in just a couple weeks, and fixing it right now is going to be very painful.
Fuck. Check engine light is on. Got the codes read at AutoZone, they say:
P0421 - Warm up catalyst system (RH) efficiency below threshold
P0431 - Warm up catalyst system (LH) efficiency below threshold
P0174 - Lean Air/Fuel ratio bank 2
I'm replying based on experience, not on knowledge.
Before panic, try filling the tank with "good" gas... not higher octane, but from a trusted gas station.
Be sure the cap in on tightly, as it should be
Try driving thru this first and maybe second tank of gas to see if the light goes out, and or the codes disappear.
This experience did happen with my grandson's Subaru, and the new gas did the job.
Best of luck...
You're fine.
This thread is instructive I believe (I'm guessing about your rig, other symptoms, etc). But the description seems on target. Short description: your catalytic converters are failing, gradually. This is determined by examining the exhaust flow downstream of the converters, and comparing it to some threshold. Yours seems to have crossed some threshold. It should drive fine.
and by fixing it being painful, you mean that you don't have $2000 for two new converters in your wallet, yeah?
and by fixing it being painful, you mean that you don't have $2000 for two new converters in your wallet, yeah?
Yeah.
Before panic, try filling the tank with "good" gas... not higher octane, but from a trusted gas station.
Be sure the cap in on tightly, as it should be
Try driving thru this first and maybe second tank of gas to see if the light goes out, and or the codes disappear.
This was what I was initially hoping. However, I have one of those cars where the light does not go off by itself, it must be manually turned off once triggered. And since this has to do with emissions, no shop that does state inspections is allowed to shut it off without a thorough investigation of the problem. One guy did turn it off for me on the sly, and it came back on again a couple days later, right after another refill of the gas tank. I don't think he'd do it again.
Anyone know how to turn off a check engine light?
Grr. Someone clipped the front driver's side corner of our car today. It was parked on the street near the elementary school and they were pulling in front of it to park. It looks like we'll need a small dent hammered out of the fender, a new light housing, and a new front bumper.
Fortuneately, they left a note on the windshield. It's even someone we know.
And the really good news is that we need to get it inspected this month, and Mrs. Glatt had just inspected it a couple hours earlier. So there won't be a rush to get it fixed AND inspected before the end of the month.
Resetting the check engine light will not allow the MPV to sneak through state inspections that require emissions testing; even if not illuminated on the dash. The inspection and maintenance monitors (IM monitors) will not be reset and most all onboard computers hooked to the DLC will be able to detect that the powertrain control module is not "ready." As a result, the vehicle will fail emissions testing until the powertrain control module is in its "ready" mode, and, once it is, if the repair hasn't been made, it will retrigger the DLC and the vehicle will still fail.
Fuckin Christ
Yeah, assuming that it really truly is a failing emissions level triggering the light, and not a poor gas mixture like Lamplighter suggested. If it's a gas mixture problem, turning off the light may allow it to stay off, or it may come back on again and then I'll know for sure.
Mr. Clod and I were calculating, how many "expired inspection" tickets I would have to be pulled over for before it became worth the cost of a new catalytic converter... it's a lot of tickets.
Fuck. Check engine light is on. Got the codes read at AutoZone, they say:
P0421 - Warm up catalyst system (RH) efficiency below threshold
P0431 - Warm up catalyst system (LH) efficiency below threshold
P0174 - Lean Air/Fuel ratio bank 2
I know it will not pass inspection with this issue. But I just passed in November, so I'm safe there for 11 more months. My question is, is this a dangerous thing to be driving around with, or can it hang out for a few months with no real problems other than continuing to degrade a catalytic converter that is probably going to need replacement either way? I have to drive this thing for about 10 hours of holiday travel in just a couple weeks, and fixing it right now is going to be very painful.
Yeah, assuming that it really truly is a failing emissions level triggering the light, and not a poor gas mixture like Lamplighter suggested. If it's a gas mixture problem, turning off the light may allow it to stay off, or it may come back on again and then I'll know for sure.
Just pulling stuff out of my ear here but ...
The fact that both LH and RH (left hand and right hand?) catalysts are showing errors at the same time suggests either:
a. These catalysts are shitty and have a poor lifespan built in or
b. The catalysts are fine and the problem is caused by some factor shared between them, most likely the gas you are using.
B. Let it be b.
ETA: or c. the catalysts
were fine but have been irreversibly cocked up by using shitty gas. Hope not.
You've got the cats, and some sensors (usually oxygen sensors) to report back to the computers how the cats are performing. A bad report could be a failure of either.
Only after you're sure of what the problem actually is, then explore your options
Here's a couple out of a list of 76.
Yeah, assuming that it really truly is a failing emissions level triggering the light, and not a poor gas mixture like Lamplighter suggested.
The combination of codes imply a least expensive suspect. To say more requires information you cannot obtain.
Appreciate what you have and what is relevant. Oxygen sensors do nothing until the engine heats them to maybe 600 degrees. During a warm up period, the engine dumps larger amounts of gasoline into the engine. Much unburned gas is then burned by the catalytic converter when it gets hot.
Once the oxygen sensors get warm, then the engine computer changes a fuel input. Leans out the mixture based, in part, on data from an oxygen sensor.
Apparently you have two sensors. If one is proving bad data, then the engine will dump improper amounts of fuel into the engine. This can result either in a too lean mixture (causing exhaust valve failure) or too rich (causing catalytic converter failure).
A most likely suspect is a bad oxygen sensor. Fix it now to avert damage that may cost $thousands.
Bad gasoline causing this problem would be noted by mileage changes approaching maybe ten percent. Of the maybe 100 other possible errors associate with the converter, gasoline might only explain less than ten.
This failure could be something as simple as an oxygen sensor with a failed heater. Then the engine computer, after a delay, would be expecting data that was incorrect. Or it could be a thermal junction failure inside that sensor. Either way, a $100+ sensor is a least expensive solution. I believe you have two. Don't know if the shop will want to replace both or just one.
Again, your reply is only as useful as facts first provided. You (typically) cannot obtain numbers necessary for a better answer. The shop can.
But in that case, wouldn't the presence of both (LH) and (RH) codes mean that both oxygen sensors had to fail at almost exactly the same time?
Your cats are covered by a 8 yr /128,000 km waranty, has that expired?
Yeah, it was eight years old this past January, and has almost twice that mileage. But I've decided I can afford the diagnostic, and if they tell me I need new catalytic converters, I'll just tell them no and start figuring out how to wreck the thing for an insurance payout. ;)
i talked with a friend of mine about this. we came to the same conclusion. if the "good" gas doesn't solve your problem, replace both of the o2 sensors at the cat first. then if you still get the codes, you have a bad cat.
... and if they tell me I need new catalytic converters, I'll just tell them no and start figuring out how to wreck the thing for an insurance payout.
If you need new converters, then an engine defect caused premature converter failure.
I mentioned two oxygen sensors. One before the converter and one after. Many cars do not use a sensor after the converter. But all must have the sensor before. Why would an engine problem cause its computer to detect those errors? A first sensor is giving bad numbers. Engine responds with a bad fuel to air ratio. Then a sensor after the converter reads bad numbers.
You don't know what to replace. This is just one likely suggestion. A likely suspect is one oxygen sensor causing bad numbers or improper engine operation. I see no reason to jump to a bad catalytic converter conclusion. Follow the evidence before fixing anything. The above scenario describes one possible reason for those codes.
Follow the evidence before fixing anything.
Is the evidence a trail of money? Because I could follow that, and then fix anything.
Is the evidence a trail of money? Because I could follow that, and then fix anything.
In string theory, we believe reality has 11 dimensions (not to be confused with the twelve taught in AA meetings). Money is a low level domain where the most corrupt cut throats to collect cash. Higher level diagnostics and equipment reside in a dimension where Dollars never appear in diagnostic error codes.
Raise yourself from a dimension dominated by business school graduates and other primitive species. All praise the gods of math and science. All chant verses of logic.
If you need new converters, then an engine defect caused premature converter failure.
Several forums mention this as one of that model's weak points... a common occurrence.
In string theory, we believe reality has 11 dimensions (not to be confused with the twelve taught in AA meetings). Money is a low level domain where the most corrupt cut throats to collect cash. Higher level diagnostics and equipment reside in a dimension where Dollars never appear in diagnostic error codes.
Raise yourself from a dimension dominated by business school graduates and other primitive species. All praise the gods of math and science. All chant verses of logic.
Are we talking about a car here? Cause if we are, you have just blown my teensy brain for the day. I should have had another cup of coffee before I read that. DAMN YOU TW!!!!! :p:
Yeah, it was eight years old this past January, and has almost twice that mileage. But I've decided I can afford the diagnostic, and if they tell me I need new catalytic converters, I'll just tell them no and start figuring out how to wreck the thing for an insurance payout. ;)
this is a good plan.
Wellll... looks like it might have to be my plan after all.
It definitely is the catalytic converters failing. Both failed at the exact same time? Yes, because apparently what happened is the one failed, and then the added strain on the other was too much for it to bear so it failed very shortly after.
So! I have new questions to be answered by knowledgeable people who aren't automatically inclined to get me to pay them.
1.) He says that while replacing both catalytic converters would be about $2000 all told, he can replace them with "universal" (i.e., off-brand) parts for a total of about $600. BUT, there is no guarantee it will work for any set period of time, or even at all. He hinted that this would really only be the option to pursue if we wanted it to work just long enough to sell it. But there is a chance that they could put them on, they would be completely nonfunctional with our vehicle, and we would be back where we started but $600 poorer. What are the chances these "universal parts" will indeed work with a 2003 Mazda MPV, for whatever length of time?
2.) He says that while we can continue to drive with it the way it is for some length of time, it won't be a steady decline into failure. The exhaust will get thicker, and the mileage will get worse, but then at some point in the possibly near future the house of cards will fall apart and I will suddenly only be able to go about 10-15 miles per hour. This doesn't sound to me to be the way a failing engine would work, but I know jack shit about it. Is this correct? Because I can deal with gradual, I can't deal with the engine giving out on me in the boonies halfway between here and Houston.
I had a friend years ago who had a similar problem. This was in a state with no emission testing at the time. Her cat also failed to the point that the engine wouldn't run properly. The cat was basically plugged and wouldn't let the exhaust through. So a mechanic told her he could poke holes with a screw driver through the guts of the converter to allow the exhausts a pathway through. This was illegal and allowed the exhausts to completely pass through the converter without being treated. Bad for the environment, but she got a few more years out of that car.
I doubt you could find a mechanic willing to do that for you, and it would only buy you enough time to make it to your next emissions test, where they might prosecute you when they see what you've done, but it's probably not all that hard to do yourself. Understand that I'm not recommending this, just relaying a story.
hm.
I'll tell you what I know about catalytic converters, Clodfobble. See if there's something there for you...
The catalytic converter is aptly named, it uses a catalyst, notably platinum, to convert substances in the exhaust stream to less toxic substances. The platinum, and other magical chemical stuffs, aren't consumed by this process, just used like eeensy weeensy chemical tools to rearrange the compounds flowing past. Mechanically, a catalytic converter works like this: take a double handful of drink stirrers, the hollow kind, and wrap your fingers and thumbs around a large bundle. Now, pick up the bundle and look through it. Weird, huh? It's like a straw of ten thousand tubes. Your catalytic converter is like this, but with tinier holes, and lots more of them. The surface of the straws are coated with this catalytic compound. The whole thing looks like a brick, except along the axis of the "straws", through which the exhaust flows. This "brick-thing" is contained in a kind of can with the exhaust pipe running in one end, through the cat, and out the other end.
When the exhaust gasses heat up the cat to the normal running temp, the chemistry does its magic, making the exhaust less toxic. That's when things are running right. But, naturally, things can go wrong. There are a couple MAIN ways a catalytic converter can fail.
It can be ruined chemically. One easy (well, used to be easy, now it's harder, but you get the idea) way is to run a tank of leaded fuel through the car. The car will probably be ok, but it will poison the catalytic converter. It's a goner. The lead ruins the surface so the chemistry doesn't happen. The car will run fine, but the emissions will be bad. There are other ways to degrade the cat too, if your car is burning a lot of oil, that can crap it up too. So, you can foul up the cat chemically (pun intended).
You can also ruin a catalytic converter mechanically. That "bundle of straws" I was telling you about? In the cat, they're made of ceramic, like your.. well, I don't know what it's like. but the upshot is the thing is FRAGILE. And it is impervious to heat, that is, you can't melt it, and "send it down the tailpipe". If it gets broken anywhere, even a little, it will crumble, maybe slowly, maybe all at once, and you will have a MECHANICAL obstruction to your exhaust flow. This, as you may well imagine, is bad. This is (probably) the "plugged up" scenario you heard. I can hear a failing catalytic converter, they have a distinctive tinkling sound at low speeds. That is from the ceramic element rattling around in the metal box that contains it. When they're new, they are neatly, and tightly fitted inside the box (it could be many different shapes, box, cylinder, tube, lozenge, etc, whatever). As the car is driven, and it gets shaken around, it's possilble that this ceramic honeycomb gets rattled around and maybe knocked loose a little. Imagine it's still in there, but knocked around some, so that the corners are rounded a little. Now it just sits in the can, which is fine, but it's a ceramic "brick" sitting in a sheet metal "can" attached to the exhaust plumbing. It's gonna rattle. That's what I can hear, you could hear it too.
Anyhow, the cat that comes with the car is designed specifically for that car in lots of ways. Like, where it connects, how hot it will get when the engine is running normally, how much flow it can accomodate, how much catalyzing surface area is available to the exhaust, etc etc etc. Your "universal" one isn't designed with these specific parameters in mind. It likely has the same chemistry setup, but will it be hot enough? too hot? too restrictive? too "loose"? etc etc etc. These are the kinds of unknowns that give the mechanic pause regarding the efficacy of the universal parts. I think the chance that the universal units would NOT WORK AT ALL is low. Unless they're like, mock ups or some other nonsense. I think you could just BYPASS the flippin converters all together and the car would still run, but you'd be passing untreated emissions. But the car would run.
Does this help?
V: Once that catalyst is destroyed, doesn't the exhaust develop a really stinky smell.
I've been behind cars that had such a stinky exhaust,
and I humored myself by thinking it was a bad converter.
Could be. ??
Stink is often sulfur, and I associate sulfur with diesel, not gasoline, but certainly, if you're not treating the exhaust as designed, there could be such a side effect.
It definitely is the catalytic converters failing. Both failed at the exact same time? Yes, because apparently what happened is the one failed, and then the added strain on the other was too much for it to bear so it failed very shortly after.
That type of failure means one converter failed months earlier. And the oxygen sensor only for the failed converter was reporting that failure long before a second converter failed. You did not report those those symptoms.
To have both converters fail so quickly requires something that causes complete damage in maybe one day. For example, contaminated fuel that permanently damaged both converters.
A catalytic converter simply burns gasoline that an engine did not. Converts unburned gasoline (and other pollutants) into nitrogen, oxygen, water, and other non-pollutants. A failed converter does not reduce gas mileage. It just stops converting gasoline, et al to non-pollutants.
Only way a converter can reduce mileage is to collapse and restrict exhaust flow. This becomes obvious from a noticeable reduction in acceleration and decidedly changed engine noise. Two converters do not fail within the same hour. I would get a second opinion.
What will a mechanic do when changing a converter? Automatically replace oxygen sensors that might be defective. Then the vehicle owner can only assume the mechanic was correct.
A P0174 error code is unrelated to the converter. Implies an engine problem; not a converter failure.
The vehicle is a six cylinder engine. Usually, two converters mean one for three cylinders with no connection common to all six cylinders. If all cylinders connect to a common pipe, then much less expensive is to design one converter for all six cylinders. All six cylinders connected to both converters leaves me suspicious. A third reason why I have trouble with his conclusions.
What happens when one oxygen sensor fails? It reports a too lean mixture. So the engine dumps too much gas into cylinders and converters. While dumping maximum gasoline into the engine, a failed oxygen sensor still reports “too lean” - error code P0174. A resulting overheated converter fails due to burning too much unburned gasoline. I don’t believe this is your problem. But it is another example of what better describes your symptoms.
Big V - excellent description.
Lamplighter - stinky exhaust can also be a car running on LPG or even biodiesel.
TW - yeah, that bit about one cat failing thereby "putting extra strain on the other"... :eyebrow: assuming they're parallel, this makes no sense.
But could they be serial?
Come to think of it, probably not, because it doesn't explain the LH and RH codes. Ideas, anybody?
And the oxygen sensor only for the failed converter was reporting that failure long before a second converter failed. You did not report those those symptoms.
Which symptoms was I supposed to report? My check engine light was not on prior to this episode. It was running fine; still is.
In fact, the check engine light has not yet come back on, since it got shut off yesterday after the diagnostic. I'mma keep waiting...
Which symptoms was I supposed to report? My check engine light was not on prior to this episode. It was running fine; still is.
In fact, the check engine light has not yet come back on, since it got shut off yesterday after the diagnostic. I'mma keep waiting...
Think horses, not zebras.
If your mechanic reset the check engine light and you are driving with "good" gas,
I'll suggest that both converters did NOT fail at the same time, or at all.
Instead it was a loose gas cap or something like that.
If the check engine light comes back on right within just a few miles, that's one thing,
but if it stays off for a longer, I suggest it's your mechanic that is failing.
Get a second opinion, or third, from a reputable establishment.
.
Yeah, when the other guy shut it off for me on the sly, it came back on within 2 days I think. So we'll see. I'm certainly not having any work done on it if the light stays off.
I also went ahead and ponied up for a guy at justanswer(.com.) Basic freelance expert site, about $18 for a conversation as long as you need it to be, I've had success using them before. Anyway, he said yes, the catalytic converters in a Mazda MPV are in parallel, but if one is mostly plugged up, then it will cause exhaust to back up into the engine and thus be forced by pressure into the other one, leading to the "added strain" effect. He said it was kind of unlikely, since the parts are the same age, it's not like I have one terrible one and one that's fine, unless maybe one sustained damage at some point (which is possible, I did go over a really violent pothole over the summer that knocked my alignment way out of whack.)
He noted, however, that there are also two O2 sensors, and one wouldn't affect the other, so even if it is actually sensor issue we're still looking at two sensors going bad at the same time (which is pretty much the issue tw noted, except instead he accused me of not mentioning that the first O2 sensor must have been failing months ago. :)) He said the only other possible thing that might cause these codes is an exhaust leak somewhere up the line that might be confusing both O2 sensors, though he said again this would generally cause a sensor code, not a converter code.
Which symptoms was I supposed to report?
If a first failed converter put extra strain on the second, then you reported a failure of the first converter a month plus ago. A second converter failed only recently. As I said, those are the symptoms you were supposed to report if the mechanics diagnosis was accurate. You did not report those symptoms.
You did report symptoms that, for example, report a failing oxygen sensor. It was probably first failing as much as a year ago. Could have been seen long ago by a computer attached to the diagnostic ports. But only recently got bad enough to cause an error code. Do not confuse that oxygen sensor with others on the converters - which, in hindsight, I believe you and others were doing.
Meanwhile, the mechanic's analysis (bad converters) do not explain error code P0174.
An intermittent error code implies your always existing failure is slowly getting worse. Or only gets reported when detected in consecutive engine restarts.
Furthermore, error code P0174 may not cause a check engine light. May be detected repeatedly by the engine computer. But only reported on its diagnostic port.
Some designs have a ‘diagnostic plug’ that, when attached, causes unreported error codes to appear as a flashing check engine light.
Driving conditions (and even different gas) may cause a marginal problem to be worse. Always there and detected by monitoring numbers from various sensors. Those codes can be created by a long list of possible suspects. Blaming two failed converters was way down the suspect list.
Suspect list could be shortened significantly by monitoring numbers from various sensors, as noted above. But you cannot do that without a maybe $120 computer that plugs into every car's computer (ie Car Chip). Check engine light can be cleared by that layman’s tool, or sometimes by a ‘diagnostic plug’.
A least expensive solution is to watch this problem. Wait for it to become so obvious that any mechanic can fix it the first time. However if a check engine lights repeatedly, then fix it now to avoid possible future engine damage.
I suspect a P0174 error code still exists. That error code, alone, does not trigger a check engine light. But my wild speculation is based only in experience - not in facts required from the shop manual. Speculation is best anyone here can do without further information from that plug-in computer (sold even in Sears and Wal-Mart) and from a shop manual.
Your best suggestion is in a paragraph that starts, "A least expensive solution ...". I, on the other hand, have a nasty habit of doing things on cars that also exposed Saddam's WMDs and Tokyo Electric's lies about Fukushima. Ruthlessly, finding numbers and irrefutable facts (that explains all three error codes) requires information currently not available.
Suspect list could be shortened significantly by monitoring numbers from various sensors, as noted above. But you cannot do that without a maybe $120 computer that plugs into every car's computer (ie Car Chip). Check engine light can be cleared by that layman’s tool, or sometimes by a ‘diagnostic plug’.
Or even
as cheap as $76.00. Looks like a neat little device, actually. Perhaps...
black electrical tape.
this
Sorry, Fob. If it were me, I'd go for cheap fix and trade in, but I'm kind of biased because that's the point I'm at with my van. Or at least was before I wrote off the Focus....
Instinctively I would have, but the guy scared me with the possibility (or outright lie?) that it might be completely non-functional with my car, and we'd be $600 poorer and no better off.
However, the check engine light has not yet come back on. We shall see, oh, we shall see....
It definitely is the catalytic converters failing. Both failed at the exact same time? Yes, because apparently what happened is the one failed, and then the added strain on the other was too much for it to bear so it failed very shortly after.
Well this has turned into a complete clusterfuck.
We told the mechanic we did not have the money for the repairs, and at any rate, we didn't have the time or energy to deal with this until after the holidays. He says no problem, but hey, they've got a no-interest financing option, and we should go ahead and apply for the card today so that the account will be active when we're ready. We are resigned to having to fix this at some point in the future, so we do the application. He also says that since the parts will take awhile to come in, he will order them now so that they will be in stock when we are ready.
So we drove all over Texas during the holidays, probably 1000 miles total, and the check engine light still did not come back on. The mechanic called me several times just before we left, and just after getting back, pushing me very hard to come back in and have the repairs done. Suspicious, we took it to a second mechanic... and the emissions tested just fine. Catalytic converters are A-OK, they said. HMMM.
We are prepared to call this a simple error on the first mechanic's part, though we suspect he may have known that the initial error was really just a bad tank of gas. But before we can call him to tell him the "good" news, he calls us and leaves a message cheerfully saying that they have gone ahead and charged the no-interest account we opened for $2,303, for the repair we "authorized," and wondering again when we will come in and have it done.
What the fucking fuck?!
Mr. Clod calls, and lets the guy know 1.) about the good test results on the catalytic converters, for which the guy has no explanation, 2.) that we have closed the goddamn account, and 3.) that we will be disputing the charges, and he's insane if the thinks that the card issuer is going to let him charge for parts he still has in his possession and labor he never did. The guy starts talking about restocking fees for the parts, and the conversation ends at an impasse, with Mr. Clod refusing the proposed 25% and the mechanic saying he'll check with the parts manufacturer and find out if they can "cut us a break." We actually agreed between ourselves that we'd be willing to pay 10% (of the parts cost only, certainly not the labor) just to make the problem go away, but the guy never called back to negotiate further.
So fine. Royal screwing averted, never going back to that mechanic again. Still have to deal with getting the charges off the account, but we feel confident that will happen, it will just take some legwork. Done and done.
And then yesterday, the check engine light comes back on. Fucking
fuck.
If the shitty mechanic had just been patient, we'd be in his shop right now, getting the repair done. But his behavior regarding the credit card is unforgiveable, so at best we're going to someone else. Except, of course, we still don't have the money for the repair, and what are the chances that we will be able to open a no-interest car repair account now, when we just opened one, closed it days later, and currently still have $2300 sitting on it? I find that unlikely.
Kelly Blue Book is worse than we thought, the minivan is at best worth $2300 in its entirety, maybe less. So I purchased an OBD-II code reader off Amazon, with which I can shut off the light myself, and hopefully we can trade it in quickly before it comes on again. We did find another MPV at a dealer that is 2 years newer, has less than half the mileage, and is listed at $8000. So that's probably the one we'll get, if we can make the trade-in work.
Sigh.
Geeeeessh, what an episode.
If you've not signed a work order, just deny deny deny.
Maybe once you get the check engine light turned off, and good gas,
it might help to invest in a new gas cap, and be sure it's on tight at each filling.
A second mechanic on a different side of town might be a good investment too.
It's not the gas cap, man. The code that came up today is the same one as before, failing catalytic converter. The car is almost 9 years old and has 155,000 miles, it's not that surprising.
Clodfobble - what you suggest seems a bit unethical.
It's not the gas cap, man. The code that came up today is the same one as before, failing catalytic converter.
Now that you have a reader, view the oxygen sensor voltage yourself. As posted long ago, if the O2 sensor is defective, it is reporting a voltage reading that is off on the edge. Intermittent. Therefore the engine computer is intermittently dumping wrong amounts of fuel into the engine. Different gas even from the same station will push that marginal voltage over and back behind a failure line. Obvious when the diagnostic port provides an actual volt number.
Still never answered were answers to tests that would have said so much more. For example, floor it after each restart. Because (and again) some defects are only reported when the accelerator is moved the exact same way after every consecutive restart.
Eventually that defect will become so bad that any mechanic can find it. But this you know because my post was based in provided and known facts. No reasons existed to suspect catalytic converters as defective. Your emission tester only confirmed what was obvious because reasons for that conclusion were also posted.
Engine light and code does not say what is wrong (as others have mistakenly assumed). It only says where to start looking. “Looking”: as in CSI's, "Follow the evidence." Viewing actual numbers - ie voltage from that oxygen sensor. Which is read from the computer by an OBD2 reader (ie Car Chip) attached to the diagnostic port.
What should be obvious to all and is obvious to you - a gas cap has zero relationship to what comes out the exhaust.
Now, did the $2+K mechanic explain the whys as I have done? Welcome to everything in the world. Without reasons why AND numbers, then the guy (any guy) is probably lying. Welcome to history taught by Saddam's WMDs.
Better dealers have a big computer that both reads those numbers AND does the voltage analysis for them (and you). Did the garage that did emission tests use that computer? Or just test emissions with a wand inside the exhaust pipe? Did he provide actual numbers for CO, CO2, NOx etc? Nobody cares if those numbers are good or bad. Only relevant is the actual value and what the manufacturer limits for each were supposed to be.
Whereas the problem could be with other system parts, one likely suspect was one particular oxygen sensor that was not the O2 sensors others were only assuming. Reread those posts to see what your emission test station may have also confirmed.
A diagnostic port is only reporting on what sees symptoms. It does not report what is wrong - as your $2+K mechanic probably has done. Due to marginal operation of a first oxygen sensor, then other following oxygen sensors (after the cat converter) may be reporting symptoms of that defect.
This is only hard if others assume a diagnostic message actually reports a problem. Diagnostic message about the cat converters never said those are defective. Only said what is coming out is incorrect - only reported a symptom. Use the OBD2 to read voltages from that O2 sensor - which is not the one reporting an error. And answer all previous questions including those from last month.
It's not the gas cap, man. The code that came up today is the same one as before, failing catalytic converter. The car is almost 9 years old and has 155,000 miles, it's not that surprising.
OK... no reproach intended
Clodfobble - what you suggest seems a bit unethical.
Yes, it does.
On the other hand, I don't believe that a dealership is going to resell this vehicle for anything but scrap. At this level, what they are really doing is mentally figuring the cost difference as just a discount on the car I'm buying, and taking possession of the trade-in as a convenience. But if I don't have that "valid" trade-in, it will be harder to negotiate the same discount they could have given me anyway.
And answer all previous questions including those from last month.
You crack me up, tw. Seriously. When the OBDII reader gets here (5-8 business days with FREE SUPER SAVER SHIPPING,) I'll see if I can figure out how to get it to report a voltage number for both O2 sensors. Just for you, because you made me laugh.
When the OBDII reader gets here (5-8 business days with FREE SUPER SAVER SHIPPING,) ...
Those many previous questions required no ODB2.
For example. Start the car. Drive it on a fixed course that includes one spot where you literally floor it. Do not turn off the engine until you are right back where you started. Repeat that at least three times. Its computer might seea a same failure all three times. But does not report some failures until you have driven it the exact same way after each new restart.
Asked were other important questions such as how an emissions test was performed. By connecting to the computer diagnostic port? By using an exhaust pipe wand? What were numbers for each pollutant? Also important information. And did not require an ODB2.
For example. Start the car. Drive it on a fixed course that includes one spot where you literally floor it. Do not turn off the engine until you are right back where you started. Repeat that at least three times. Its computer might seea a same failure all three times. But does not report some failures until you have driven it the exact same way after each new restart.
I don't have the CarPro scanner, the check engine light is currently my only method of failure reporting. Right now, the light is already on. It does not go off without being manually reset.
Asked were other important questions such as how an emissions test was performed. By connecting to the computer diagnostic port? By using an exhaust pipe wand? What were numbers for each pollutant? Also important information. And did not require an ODB2.
We didn't watch it happen. It was done however your average state inspection place does it. We didn't get any numbers, we just got a piece of paper indicating that it passed the state inspection threshold (which I am told is somewhat lower than the check engine light threshold.)
stay tuned. there will be another job posted in my projects thread.
Because plt is the coolest and most awesomest person in the world!
Car, Car, C-A-R,
Stick Your Head in a Jelly Jar
Regionalism. We used "mustard jar" in my neighborhood in the 60s.
We were all about alliteration in New York in the 60s.
We were so poor in Maine in the 70s that we only had the first line. Didn't even know there could be a second one.
Only said it when it was time to get out of the street to let a car go by.
Only said it when it was time to get out of the street to let a car go by.
Well, duh.
j/k :D
We were so poor in Maine in the 70s that we only had the first line. Didn't even know there could be a second one.
Only said it when it was time to get out of the street to let a car go by.
A whole line?
Luxury! We only had the scream and the thump to alert us to get out of the way. That, and a mouthful of hot gravel.
BigV @ 2:11
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We were so poor we couldn't even pay attention.
i was so poor i had to fart to have a (s)cent in my pocket!
Seriously. When the OBDII reader gets here (5-8 business days with FREE SUPER SAVER SHIPPING,)
Once the Car Chip arrives, it must be setup. After downloading the software, the Car Chip must be told what parameters to monitor.
The first is vehicle speed - a default. Next is Engine Speed. O2 Sensor voltage. And then Short term fuel trim. The first three parameters should be set to a 5 second interval.
Attach to the car (when still cold). Take a maybe 5 minute drive. Best to take a road where long steady conditions occur. So that multiple 5 second data from the O2 Sensor can be compared to engine speed and short term fuel trim.
First notice what an O2 Sensor voltage is when the vehicle is cold. Ideal voltages will probably be between 0.6 and 0.7 volts once the sensor is hot. Voltage will increase to something like 1 volt when the engine is dumping lots of fuel into the engine. When more fuel is being burned and more fuel is exhausted unburned (wasted energy and a lower gas mileage).
Fuel trim says how long each injector is on; how much fuel is being dumped into the engine.
That is what the O2 sensor does - adjust the amount of fuel to no longer do gross waste; what a carburetor did. Carburetors would dump massive amounts of fuel hoping the engine would burn as much as possible. Leaving a catalytic converter to burn what remains.
If too much fuel is detected in an exhaust, the computer assumes a defective catalytic converter. Not necessarily. The error code only says where to start looking. Some mechanics will not think through a problem. Automatically replace what they first suspect (ie blame the catalytic converter). Do not assume what is wrong before replacing anything.
I'm sorry tw (I really am, not being sarcastic,) but you misunderstood. I didn't get the Car Chip product after all, only a regular OBDII sensor. My goal was to be able to turn off my own check engine light, both now and in the future. I don't think the item I got (
this one) can read those values for you.
I didn't get the Car Chip product after all, only a regular OBDII sensor.
Is that a hand held OBD2 display? Not the Car Chip Pro that reads and stores data from a car? And is then read via a computer's USB port? That is the only CarChip Pro I knew of. Did not know a handle display existed.
Yes, mine is not a CarChip Pro product at all. It's a different brand of OBD2 sensor, of which Amazon had at least a dozen. It doesn't connect to the computer, and I don't think it can be used while the car is running.
But at this point I'm really sure it's the catalytic converters. (I know you're not sure, but you take an inordinate amount of evidence to be sure, and I am sure enough to meet my threshold. :)) The really good news is that I successfully ordered compatible parts online myself, and plthijinx is completely. awesome. and is going to install them for me, with the help of a friend and a welding torch.
i was so poor i had to fart to have a (s)cent in my pocket!
:)) The really good news is that I successfully ordered compatible parts online myself, and plthijinx is completely. awesome. and is going to install them for me, with the help of a friend and a welding torch.
The awesomeness of plthijinx comes through x 2!
Thats awesome Clod! Way to step up plthijinx. :thumbsup:
The awesomeness of plthijinx comes through x 2!
BWAHAHAHAHAHHAAA! now THAT was funny!!!
it's nothing really. gonna be a PITA but certainly easier than when my friend and I changed out the transmission on my old truck.
<------- FAIL!
hate to admit it but i couldn't fix it. the cat's were the wrong part to start off with so we thought, ok well, lets just change the sensors. way in the fk easier said than done. one sensor was right in front and easy to get to but i'll be damned if i could bust it loose. i even put a torch on it twice and still couldn't get it loose. i gave in. said hell with it. i don't want to make it any worse than it already is. so we rode go karts instead.
ETA: pics
first pic, albeit a little fuzzy you can see the spark plug looking front sensor
second pic: torch
But the go karts were awesome! And no trip wasted, I was gonna be here to pick up my stepkids today anyway, and I can return the unusable parts. It was worth a try.
I think those have a left-hand thread.
[COLOR=White](Trouble maker)[/COLOR]
The one thing you need is a left handed monkey wrench.
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[COLOR="Yellow"](accomplice)[/COLOR]
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first pic, albeit a little fuzzy you can see the spark plug looking front sensor
Normally the first sensor (completely different from another oxygen sensors) is located where the exhaust manifold connects to the engine block. Is that sensor, instead, relocated to be one in your picture?
no, that was the first one. this engine, er exhaust system has the manifold and cat's as one piece so to change the cats you in turn have to remove the manifold. there was that front one there, another down stream and i couldn't find the fourth. (1 on each cat then the downstream one + the anonymous one)
i tried going both clockwise and counter. those suckers are on there. 9 years of cooking on hot ass exhaust. i was afraid i was gonna cause more damage than good so i quit
no, that was the first one. this engine, er exhaust system has the manifold and cat's as one piece so to change the cats you in turn have to remove the manifold.
But is that pictured oxygen sensor the one normally located (on most cars) only six inches from the engine block? Meaning of the word 'first' is not clear.
Are there two (the picture only shows one) sensors - each one for three cylinders? Of course another two sensors are after catalytic converters. Those would be reporting a failure. A report that implies those 'after' sensors are 100% OK.
A torch should be sufficient to remove most 'decade rusted' parts. Especially any oxygen sensor mounted on that stainless steel exhaust pipe. But if overheating due to excessive gasoline, then removing a part (ie oxygen sensor) would be difficult.
Implied: catalytic converters damaged and now seized by an engine always dumping excessive gasoline into the converters - as discussed earlier. Diminished (not yet failed) converters may be a symptom of a long existing problem that also caused lower gas mileage.
Federal law says an exhaust manifold must not fail for first 100,000 miles. Which is why most pipes are good for less than 200,000 miles. That pipe and cat converters typically do not fail. Says why those parts are so expensive. Parts that don't fail often have highest profit margins. We used to charge a 100% markup.
So, if an oxygen sensor is the first (my original question), then doing anything to replace it (soak it repeatedly in WD-40 for 24 hours before using the torch to heat it while using a socket wrench to remove it) is a best shotgun solution.
BTW, never saw a reverse threaded oxygen sensor. If reverse threaded, then a shop manual was blunt about that unusual threading.
Spending another $25 for the Car Chip Pro would have said much more. But if any part is to be replaced, a most suspect part is probably that 'first' oxygen sensor. Not any sensors after the cat converters. Replacing only that sensor is by far the least expensive of all 'shotgun' options.
I thought WD-40 was flammable - apparently not?
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It doesn't matter, after you spray and let soak, the flammable component is pretty much gone.
He was pretty sure of the outcome.
I wouldn't have tried that right next my car :eek:
i was afraid i was gonna cause more damage than good so i quit
And that, folks, is a
really good mechanic/engineer.
And that, folks, is a really good mechanic/engineer.
lol, hardly. i hate not being able to do/complete a job. this one won. it beat me. what can i say? still irritates me though.
That's exactly what I mean. I also hate starting a job and not finishing it, I'm sure we all do. But I hate it more when I over-reach my abilities and break something and turn a maintenance need into an emergency fix. Recognising when you are at the limits of your abilities and the tools at your disposal is a prime skill. Well done.
i hate not being able to do/complete a job. this one won.
Not necessarily. It may have set a trap. What were consequences of, for example, a partially removed pipe? You would have to replace an entire exhaust manifold and catalytic converter that cannot be removed.
You may have outsmarted a car that had laid a trap.
However, just as fun is getting into that mess. And then discovering how to solve it. Either you outsmarted a car. Or you just missed out on having fun. Either way, you did not lose. Only and maybe did not win.
A simplest ‘shotgun’ solution is replacing an oxygen sensor. Soaking in WD-40 for at least 24 hours may be helpful.
I was thinking I might get a small above-ground pool, fill it with WD-40, and soak the whole car in it. Sure, it would smell funny, but the kids would love sliding off the seats.
I was thinking I might get a small above-ground pool, fill it with WD-40,
I love the smell of WD-40 - anytime. It also cures bed bug problems.
[COLOR="White"]pssst - UG ... you need new bait? try WD-40 next time.[/COLOR]
omg don't soak the whole car in wd-40! It just occurred to me that every bolt will loosen simultaneously and the car will fall apart while driving down the highway, like a cartoon!
Like the giant lego ball!
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The difference between crap Liberty gas and Shell gas would (for example) result in maybe an 8% difference without any noticeable change in idle smoothness. If your numbers are as reported, then Liberty gas should have caused a noticeable mileage difference. The fact that you saw no difference is troubling.
In another event, a tank of Mobil destroyed my fuel injectors. I knew something was wrong due to a slight roughness in idle. But the resulting mileage change was from 32 MPG to about 27 MPG in that tank. And 24 MPG in the next tank. (Honda replaced those injectors for free). In that case, diagnostics never reported a problem.
In another case, a problem with an EGR valve kept causing a check engine light. No mileage change. Symptoms that helped me trace the problem to a hard and not easily diagnosed problem. (BTW, EGR valve is not connected to the idle system; so did not affect idle. And that failure was unique so as to not affect gas mileage.)
Examples of different failures that do and do not result in mileage changes. And that isolated the problem quickly to a shorter list of suspects.
Assuming that 5% coincided with road conditions (heavy traffic, summer open road driving, etc), then is we can assume you have a problem traceable to the idle system and that does not affect the other 'normal operation' system.
BTW, remember Cloud's problem. That was also traceable to the idle system and that would not cause mileage changes. That mechanic had one clear advantage. The Civic's diagnostic system pointed exactly to the defect - which that mechanic refused to address. An example of why some people just refuse to learn good diagnostic procedure.
Now, with Shell, what is happening? What are the latest symptoms?
For the last two months we've been putting nothing in it but Shell. No improvement. I put a bottle of fuel injector cleaner into it. No change. Still a rough idle after it warms up.
So I bought a CarChip Pro so I can monitor RPMs and other stuff.
I just started it and let it idle for 8 minutes or so. I didn't touch the accelerator. The first 4 charts I got are below. It started off fine, and the idle got progressively rougher, until at 8 minutes in, the roof liner started vibrating it was so bad. Then it was dinner time, so I turned it off.
Chart 1 is RPM. You can see it gradually slows down. I didn't touch the accelerator ever.
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Chart 2 is the throttle position. I had no idea what this would show, but here you go. It shows little when you don't step on te gas.
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Chart 3 is the first of several oxygen sensor readings it can take. I ahve no idea what this means, but this is O2 B1, S1
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Chart 4 is also an oxygen sensor reading. It's called O2 B1,S2, whatever that is.
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I'll have to double check the shop manual, but if I recall correctly, it should read between .1 and .9 volts. It goes a little below .1 volts.
There are a whole bunch of other readings I can have this make, but you can only do 4 at a time, and you have to take it out of the car and hook it up to a PC to change what you are monitoring.
It's a neat little gadget.
A car at idle runs completely different from one at normal engine speed. At idle, a car must dump more gas in the engine while making the car work so inefficiently as to run at only 800 RPMs. Most pollution occurs during idle. Also why cars sitting in bumper to bumper traffic consume so much gas (another reason why hybrids are so necessary).
IOW a better test of your O2 Sensor and other factors is to be moving at constant speeds as indicated by little or no throttle movement.
Now, some facts. In the first minute, an O2 sensor must get warm before it reports anything. So newer technology sensors have an internal heater to make them hot (work) sooner. In your case, sensor one got to temperature quickly. Sensor 2 seemed to be doing nothing until engine exhaust finally heated it. Sensor 2 may have a defective heater or for some reason is taking longer to get the temperature. (BTW, I am assuming this is a 6 or eight cylinder since fours only need one O2 sensor. If this is a four, then the second sensor may be after the cat converter making this analysis bogus.)
Sensor 2 appears to be reporting inaccurate voltages. An O2 sensor is typically between .6 and .7 volts when the engine is running optimally. When dumping gas excessively, then the voltage is typically about 1 volt. Your sensor two appears to be reporting numbers that are low. Or one side of the engine is using more gas than the other.
However, how electronics measure those voltages might explain different numbers. Your particular car may measure or report those voltages differently. Normal voltages for an O2 sensor must be confirmed from the shop manual. But something is different on both sides of the engine.
Throttle clearly remained closed the entire time. But after 8 minutes, your idle was not yet at 800 RPM? The car should have been hot and at idle after 8 minutes. You might repeat the test while monitoring engine temperature. Your thermostat might not be fully closed (partially sticking) when the engine is cold. Therefore the engine is taking too long to warm up; wasting gas in the first ten minutes.
What you are looking at? Fuel injection is a switch (much like Cloud's idle adjustment valve) that is turned on and off quickly by a microprocessor. Time of each opening (called fuel trim) determines how much fuel is dumped into each cylinder. An O2 sensor measures how much got burned. Microprocessor reads the O2 sensor to determine whether to lengthen or shorten that opening time (adjusts short term fuel trim).
Graph is each O2 sensor number (maybe) sampled only at 5 second intervals. The actual numbers vary significantly in milliseconds. Actual O2 voltage is varying many times more often and more gently. Your chart simply shows some of the highest and lowest voltages. Therefore the steep changes.
Those variations may be normal for idle. But if you see variations that large for normal RPMs, then that may also be symptoms of a problem. An engine at normal speeds should see O2 sensor voltages varying little between 0.6 and 0.7.
Notice that at seven minutes, the variations decrease to what I am more used to seeing.
Voltage should increase when, for example, when a throttle is pressed. An open throttle means intake manifold has no vacuum. So the computer dumps more fuel into cylinders (short term fuel trim increases). More fuel comes out unburned. The O2 Sensor (that I am used to seeing) reports 'more unburned fuel' at about 1.0 volts.
Again, large variation may be normal for your engine. If it was any of my Hondas, I would be concerned. Approaching eight minutes, the variations decreased. Whereas your seven minute voltages to me are too low, still, the O2 sensor varies more like I am used to seeing it.
Meanwhile, the 'Shell' test implies gasoline was irrelevant to your original problem.
You can view a relationship between short term fuel trim, throttle angle, O2 Sensor voltages, and intake manifold vacuum. To see what the microprocessor sees and responds accordingly.
Another parameter is long term fuel trim. I have never confirmed this by doing it. But a long term number would increase if the gasoline is inferior. If gas (ie WaWa) does not burn as efficiently, then engine software may respond by increasing (over a long time) the amount of fuel it dumps into the engine. Long term trim is how a microprocessor learns and adjusts from engine overall performance. Short term fuel trim is how it responds due to immediate road, throttle, load, and other current variations.
O2 Sensor is not the only input. But it varies according to how much gas remains unburned. Other inputs include a sensor that measures atmospheric pressure (are you one mile up in CO or at the shore?), and one that measures manifold vacuum. When does it know to dump more fuel into the engine? When vacuum decreases (due to an open throttle or a sudden air leak). Ignition timing also changes (advances) when more fuel is dumped. You can also view that relationship.
I don't remember what your car's technology is. However older cars adjusted engine timing mechanically (centrifugal force and manifold vacuum). So a sticky or binding ignition timing could be seen on that chart. I have seen where distributor grease got sticky after ten years causing engine timing to intermittently stop changing. That was also indicated by a slight knock. However some auto companies (ie GM) decided knocking is normal rather than fix an inferior engine designs. Knocking alone might not report a problem. But sticky mechanical ignition timing might be seen on the chart. Unlikely. But an example of what the microprocessor can see. But the failure is not serious enough to report. An example of why many detected problems can remain unreported by engine check lights.
Hopefully this successfully introduces simple operations inside a computerized engine. Computerized engines are simpler than carbureted. But involve fancy nouns (ie short term fuel trim) that at first sound confusing.
It just occurred to me that every bolt will loosen simultaneously
But until then, every squeak and rattle will have been eliminated.
Thanks for your input, tw.
FYI, the car is a 4 cylinder.
I was reading the shop manual as I was drifting off to sleep last night. Boy, what an annoying book. You find one list that talks about rough idle possible causes, and each cause sends you to a separate section of the book, so you go to those separate sections, and they each send you to other separate sections, so you spend all your time just flipping around from section to section. I need to just sit down for a couple hours with a notebook and take my own notes from this manual, since trying to find where I read something is pretty much impossible. I've got almost every page in this one section folded over.
Anyway, for the O2 sensor, the voltage ranges are supposed to remain within .1 to .9 volts during operation. It doesn't send you a code until the voltage drops below .05 volts, and in my idle test on my car, it never did.
I also have a few stop and go trips around town recorded, but they are confusing because there is so much variation in road and engine speed. I'll try to fit in a short trip on the highway this weekend.
One amusing thing is that this CarChip Pro is also marketed as a way to snoop on your teenage driver and tell you if they accelerate too fast or stop too fast. My wife never triggered the thing, but almost every time I stop when driving, I set the damn thing off. So I come to a stop at a stop sign and the damn thing beeps at me. Then I stop at a red light, and it beeps again. I'm not jamming on the brakes. Honest. But my wife thinks it's funny. There's some way to turn it off, but I haven't figured it out, and maybe it will make me into a "better" driver.
There was a review on the Amazon page by a dad who had purchased it to monitor his son's driving habits... and when his son got a ticket for going 90 in a 55, the son swore he wasn't going that fast, and the dad's all, "Yeah yeah, sure son. Let's check the record, shall we?" And it turned out, no, the CarChipPro had recorded a speed of only 62 at that time. Still speeding, of course, but obviously not 90. They presented the data in court and got the ticket thrown out.
There was a review on the Amazon page by a dad who had purchased it to monitor his son's driving habits... and when his son got a ticket for going 90 in a 55, the son swore he wasn't going that fast, and the dad's all, "Yeah yeah, sure son. Let's check the record, shall we?" And it turned out, no, the CarChipPro had recorded a speed of only 62 at that time. Still speeding, of course, but obviously not 90. They presented the data in court and got the ticket thrown out.
Nice! I like!
A year and 150 posts ago, I complained in this thread about a rough idle my car has. If you are a glutton for punishment, you can go back and re-read it all, starting at post 55. The problem is still there.
The executive summary is that after driving the car for a while and the engine gets warm, I stop at a light and put the car in neutral or step on the clutch, and it begins to idle. And vibrate. A lot. It's annoying. It's loud. It didn't use to be like that. It used to be smooth and quiet. Now it's rough and loud and vibrating. However, the fuel economy is as good as ever. I got 39.5 mpg on the highway on a trip back from Maine over the summer. Very pleased with that. Normally it's city driving and around 30.
We recently bought a second car, which means I can take a day here and there to work on this one, and the other one is available for use. No pressure to get it fixed in a half hour window before the next soccer game. So I am returning my attention to this problem.
So far, I've tested the engine mounts by putting on the parking brake and trying to drive forward and reverse while watching the engine. The engine barely moves. I think the mounts are good. I ran a few bottles of fuel injection cleaner through the gas tank according to instructions. No change. I paid the corner mechanic to clean the throttle body when they were doing an oil change. No change. But I recently took the air filter off to check the throttle body, and noted that it was clean, so they did the work. I tried to clean the mass airflow sensor, but discovered that this car (1996 Geo Prizm) does not have one. It has a pressure sensor instead and I understand you don't clean those.
Here's the throttle body.
[ATTACH]41652[/ATTACH]
Looks clean to me. The little square-ish hole at the bottom of the throttle leads down to the Idle Air Control valve. It looks like it might be a little dirty down there, so I may try cleaning that next. It's kind of complicated though. I'd need to remove a few hoses, including coolant lines, some data cables, and a throttle cable before I can get the throttle body off, and then take the IAC off of the throttle body and clean it out. Maybe this weekend. Seems like if I'm having idle trouble, the problem might be the idle control valve.
How do you take off a couple of coolant hoses without getting coolant everywhere or bubbles in the coolant system? Do I need to flush or bleed the coolant afterwards? Sounds like a lot to go through to clean something in the hopes it will fix the problem.
I would not waste time cleaning things. Cleaning rarely fixes such obvious problems. And might even create more problems if disconnecting the coolant is necessary.
If I remember correctly, we went through a list of suspects from the manual and other suggestions. Eliminating many including fuel and O2 Sensor. Mileage and operation when not in idel mode eliminates most suspects (including motor mounts). Listen to the exhaust pipe both on idle cold and idle hot. Any missing that corresponds to the roughness?
When cold, the idle is probably faster. Might not feel rough. A problem not apparent in cold (faster) idle might still exist and be heard in the exhaust pipe. Missing in the exhaust pipe would eliminate motor mounts and other static reasons for roughness.
Does the roughness appear suddenly or gently become obvious as idle RPMs slowly decrease?
Does this fuel injection system do a fast idle by holding the throttle plate slightly open or by opening a fast idle air valve (not to be confused with the Idle Air Control valve)? IOW is there a relay or vacuum line that partially holds the throttle open for a fast idle?
As noted previously, an idle control system operates different from high speed operation. Parts that are common to both operations (ie spark system) can be eliminated since they work fine in high speed operation. Apparently performance and gas mileage say all high speed subsystems work OK.
Some previous questions I don't recall seeing answered. How does this car perform timing? For example, does the distributor have vacuum and centrifical advance and retard to mechanically adjust when spark plugs fire? Or is engine timing done electronically? Carchip may report timing as the engine gets warmer.
One part that operates only in idle mode (not in high speed mode) is the Idle control valve. A binding valve might explain rough idle. However, if difficult to access, then better is to eliminate other possible suspects first.
EGR valve can be in that suspect list. EGR valve is open during high speed operation. But must fully seal always during idle. That valve leaking exhuast gas during idle means it too would be a part that could only affect low RPM idle. And is often easily tested. Two reasons for that leaking would be vacuum on that EGR valve at idle (when no vacuum should be opening that valve) or the valve does not fully seat (close) at hot idle. The later can only be confirmed by temporary removal and inspection. Former becomes obvious by disconnecting an EGR controlling vacuum line and covering that hose with a finger. No vacuum should exist during idle.
I don't remember the long list of suspects. Don't remember any error codes. And don't remember why we spent so much time eliminating an O2 Sensor and gasoline from the suspect list. But gas mileage and high speed performance also eliminate both from the suspect list.
I would not waste time cleaning things. Cleaning rarely fixes such obvious problems. And might even create more problems if disconnecting the coolant is necessary.
If I remember correctly, we went through a list of suspects from the manual and other suggestions. Eliminating many including fuel and O2 Sensor. Mileage and operation when not in idel mode eliminates most suspects (including motor mounts). Listen to the exhaust pipe both on idle cold and idle hot. Any missing that corresponds to the roughness?
When cold, the idle is probably faster. Might not feel rough. A problem not apparent in cold (faster) idle might still exist and be heard in the exhaust pipe. Missing in the exhaust pipe would eliminate motor mounts and other static reasons for roughness.
Does the roughness appear suddenly or gently become obvious as idle RPMs slowly decrease?
Does this fuel injection system do a fast idle by holding the throttle plate slightly open or by opening a fast idle air valve (not to be confused with the Idle Air Control valve)? IOW is there a relay or vacuum line that partially holds the throttle open for a fast idle?
As noted previously, an idle control system operates different from high speed operation. Parts that are common to both operations (ie spark system) can be eliminated since they work fine in high speed operation. Apparently performance and gas mileage say all high speed subsystems work OK.
Some previous questions I don't recall seeing answered. How does this car perform timing? For example, does the distributor have vacuum and centrifical advance and retard to mechanically adjust when spark plugs fire? Or is engine timing done electronically? Carchip may report timing as the engine gets warmer.
One part that operates only in idle mode (not in high speed mode) is the Idle control valve. A binding valve might explain rough idle. However, if difficult to access, then better is to eliminate other possible suspects first.
EGR valve can be in that suspect list. EGR valve is open during high speed operation. But must fully seal always during idle. That valve leaking exhuast gas during idle means it too would be a part that could only affect low RPM idle. And is often easily tested. Two reasons for that leaking would be vacuum on that EGR valve at idle (when no vacuum should be opening that valve) or the valve does not fully seat (close) at hot idle. The later can only be confirmed by temporary removal and inspection. Former becomes obvious by disconnecting an EGR controlling vacuum line and covering that hose with a finger. No vacuum should exist during idle.
I don't remember the long list of suspects. Don't remember any error codes. And don't remember why we spent so much time eliminating an O2 Sensor and gasoline from the suspect list. But gas mileage and high speed performance also eliminate both from the suspect list.
Thanks for the post! I'm not excited about removing and cleaning the IAC valve because I don't want to mess with the coolant unless I have to. I just read the section of the manual that talks about this, and the second step after relieving fuel pressure is to drain the coolant system. What a job!
A little more information:
1. I've only been using name brand fuel (Shell) for the last year.
2. Car has an O2 sensor next to the exhaust manifold by the engine, and one after the cat under the car. I've looked at the charts from the carchip pro, but don't really know how to interpret them. One potentially interesting thing that I noticed this weekend is that the outer protecting sleeve of the wires going the the first O2 sensor by the manifold is all chewed up and torn. There had been a cable tie holding that sleeve to a coolant hose away from the fan, and the cable tie was broken and slipped down the coolant tube. The O2 wire harness was hanging loosely between the fan and the exhaust manifold. But when I inspected the wires within that damaged sleeve, the insulation on the wires was undamaged, and the sensor sends readings to the carchip pro. So I assume it is fine, even though it looks like hell.
3. No error codes.
4. I think the timing is controlled by the computer. And I just confirmed. Manual says "All spark timing changes in the distributor are performed electronically by the Engine Control Module Powertrain Control Module." The OBD2 system will send data to the Carchip for "timing advance." But I don't know what those numbers mean.
5. Roughness is not present at cold start up, but I wouldn't say the engine is smooth either. The problem may exist when cold. Hard to tell. It gradually gets worse as the car warms up and the RPMs drop a little, but then suddenly gets a lot worse. I assume this abrupt change happens at the point when the car decides it's warm and changes from rich to lean mode.
6. There is a throttle opener that increases idle speed during start up conditions. A vacuum hose goes from the top of the throttle body to the throttle opener and appears to be what activates the throttle opener. I haven't studied this during a warm idle, so I don't know if it does anything after the engine has warmed up. The manual discusses ways to test this throttle opener, but it requires a real time scan tool to monitor RPM while you fiddle with the hoses at a specific RPM and then confirm that the engine drops to another RPM when you let go of the throttle with the hose plugged. I don't own a real time scan tool that will display RPM, so I can't test this component right now.
I am intrigued by the EGR. It looks easier to test than the IAC. I think I'll focus on that this weekend instead.
Also, listening at the exhaust pipe sounds easy. Could you describe in more detail what I should be listening for?
I am intrigued by the EGR. It looks easier to test than the IAC. I think I'll focus on that this weekend instead.
Also, listening at the exhaust pipe sounds easy. Could you describe in more detail what I should be listening for?
A good car will have a constant 'hum' (as it were). Misses will sound like a 'poofff'. Listen for this on any car. Best designed (high performance) engines have a smoothest and least noisy exhaust. (Listen to Harley, Camaro, Mustang and pickup exhausts to hear inferior engines.) But a cylinder miss (the pooofff) is quite obvious in an exhaust. Especially listening within feet of that exhaust pipe during idle.
Another sign of a defective engine is backfire as the car decelerates. Only scumbags think that crap sound is cool. An engine without defects outputs least and smoothest sound when a foot is removed from the accelerator.
EGR valve is typically so easy to access and test as to be a first thing to remove and inspect. (Some may require a new gasket to reinstall. Better cars typicaly have no gasket damage when an EGR valve is removed.)
EGR valve opens with vacuum that you can even create with your mouth. Flow from exhaust manifold to intake manifold can also be tested (for a good seal) with your mouth (and with something to keep your lips looking fashionable such as black lip balm).
If an EGR valve has a wire connection, then a computer is monitoring its operation. If no wire, then the computer might not know an EGR valve is failing. So disconnect a vacuum hose to that valve. Rev the engine. A vacuum will be felt only when a warm engine is at higher revs (above 1500). And never when the engine is at cold or idle. A leaky EGR valve can create rough idle.
Only EGR failure a computer cannot see is leakage from exhaust manifold to intake manifold. Your 'lip' test would expose a leak.
Disconnecting coolant hose is easy (once a few tricks are learned). Often best done by partially emptying the radiator into a pan via a cock located conveniently at the bottom of the radiator. Refilling is also easy on better designed cars. An air bleed port at the highest point of engine coolant is opened to let any trapped air bleed out when refilling. But disconnecting coolant hoses and removing the IAC valve is a pain that usually results in a little of your blood left in an engine compartment. (Or get construction gloves from a hardware store.) Requires care to not harm wires or control cables. And mark each vacuum hose before disconnecting.
BTW, one remote problem is an inspection mechanic who inadvertantly swapped two hoses. Better cars actually number each hose. Sometimes a vacuum hose diagram is on the bottom of the hood (bonnet).
EGR valve is typically 'inspected' with your mouth. IAC valve typically requires better equipment and knowledge. Just another reason why inspecting the EGR valve is better done first.
Noted previously - the idle system and normal operation operate completely differently. To idle, a car must change engine parameters to become very inefficient. And timing is different.
Car Chip can view engine ignition timing verses RPM and engine loading (if your computer reports loading to Car Chip ). During idle, timing is at zero degrees top dead center. Or a few degrees off center. As engine speed increases, timing (when the spark plug fires) advances. Generally, fuel is ignited before fully compressed. And continues to burn (pushing the piston) after the exhaust valve opens. When an engine becomes more loaded, then timing may retard closer back to zero. Causing more power but more unburned fuel.
To make an engine inefficient at idle (so that it can run at a pathetically slow 800 RPMs), timing is moved to zero. If timing does not move back to that point, then it might run rough at low RPMs. Shop manual may report what that timing number at idle should be.
Computer is apparently monitoring your timing. Therefore viewing these timing numbers would only be informative and interesting. The computer was not seeing timing 'out of spec'. So idle engine timing also should be OK. View those timing numbers for various RPMs to appreciate what is happening. And to confirm timing at idle is at the right spot. Obviously timing is OK at high speed (no knocking, no hesitation, good mileage). Timing was only relevant to your timing roughness when it should be at or near zero degrees.
BTW, TDC or Top Dead Center is when piston #1 is at its highest point. That is when a spark plug fires for idle. At higher speed, the spark plug fires much sooner (before cylinder gas is fully compressed). IOW timing advances ten or as much as 30 degrees Before Top Dead Center (BTDC). If not, then an engine can be less efficient and 'knock' due to unburned fuel. But again, your mileage number suggest timing during normal operation is correct.
Timing at idle sometimes changes with engine temperature. A cold idle might have a different timing from a hot engine at idle.
Engine timing was why so many spent maybe $100+ every three months for a tuneup (new points and condenser). EPA requirements (1975) made that tuneup unnecessary by replacing mechanical parts (1900 technology) with electrical parts (1962 techology). And later (1980s) with something also more reliable - a computer.
Four items to consider - EGR valve, IAC valve, engine timing, and swapped vacuum hoses. Also useful might be other items on their 'suspect' list. Since something unique to your car design (something else that works differently at idle than at normal speed) may be overlooked by me.
Glad I can test the EGR with just my mouth (I'll use some clean tubing so I don't get gunk in my mouth.) I was thinking I'd have to buy one of those hand operated vacuum pumps to test it. I like excuses to buy tools, but I've been spending too much lately.
There are so many vacuum hoses! I was looking for possible disconnected hoses and kept finding new ones to inspect. They are everywhere.
There are so many vacuum hoses! I was looking for possible disconnected hoses and kept finding new ones to inspect.
Better designed cars have a number on each hose. A vacuum hose diagram confirms each connection. I once found two hoses reversed. Car still started.
EGR valve will not open fully with 'mouth vacuum'. But just enough to confirm its works. More important is no leak (ie stray piece of carbon) from exhaust to intake manifold.
I listened at the exhaust, but didn't hear anything other than a steady hum. After a while some water started consistently sputtering out, and I noticed some pinhole leaks in the muffler where water was dripping out.
I turned my attention to the solenoid that opens and closes the EGR. I checked for the proper resistance between the prongs, and then check that there was no continuity with the outer frame.
[ATTACH]41686[/ATTACH]
I blew in the lower nozzle, and saw that the air came out the filter vent, and then I applied battery current to the prongs, heard the solenoid activate, and when I blew in the lower nozzle, the air came out the upper nozzle. According to the manual, this confirms the solenoid is OK
Then I went to the EGR transducer and checked to make sure the filter was clean. It was very clean. I blew in one nozzle, and covered the two opposite nozzles, and confirmed the air came out the sides. [ATTACH]41687[/ATTACH]
According to the manual, this confirms the transducer is OK.
Finally I took off the EGR valve. This was a little trickier because it was underneath and there wasn't much room. But I got it off and saw that it wasn't terribly dirty.
[ATTACH]41688[/ATTACH]
A little dirty, but not bad. I tried sucking on the hose that leads to the diaphragm, and could easily open and close the valve by sucking on it.
The air intake was a little dirty too, but I couldn't get at it to clean it. It was hard enough to take this picture.
[ATTACH]41689[/ATTACH]
As long as I had the valve off, I might as well clean it. So I did. Sprayed lots of carb cleaner in the different holes and sucked on the hose that leads to the diaphragm so the cleaner would get in valve area as I sucked the valve open and closed.
[ATTACH]41690[/ATTACH]
Then I put everything back together and started the car. It still vibrates a little, but it's not as bad as it was before. I can't get it to make the really annoying vibrating and sound. I'm optimistic!
There were a couple other tests I could have done if I had a vacuum pump, a vacuum gauge, and a scanner tool that showed RPMs in real time.
Maybe this fixed it. I'll pay attention for a while and see if it's fixed. Hardly drive this car at all though, so I don't know when that will be.
There were a couple other tests I could have done if I had a vacuum pump, a vacuum gauge, and a scanner tool that showed RPMs in real time.
Did not realize you had a vacuum gauge. Smooth sound in an exhaust suggests the vacuum gauge should show a constant vacuum in the manifold at idle. However confirm this. Intake manifold vacuum at a constant above 17 inches should be observed. If the vacuum gauge needle vibrates, then the problematic cylinder is indicated when the gauge point dips to a slightly lower vacuum.
Assuming the vacuum gauge is contant at idle. Then this is puzzling. Vibration at idle implies a missing cylinder. And yet the exhaust pipe sound suggests no missing. Vacuum gauge will probably report the same 'no problem'. If so, move on to some other suspect. This engine appears to be operating smoothly on all cylinders during idle mode. And gas mileage suggests it is also working properly during normal operation.
Every part of a drive train and engine must be isolated from the car's body. Even a radiator does not make a direct connection; connects to the body via rubber isolators. Is it possible that something (ie exhaust pipe) is touching the body as it gets warm? For example, an exhaust pipe was hung slightly twisted? Or a heat shield place moves slightly with heat?
Well, I don't have a vacuum gauge. Maybe I should get one. Seems like a waste of money for a tool I'll only use once. But I wish I had one.
I listened at the exhaust, but don't trust my skill at identifying the sounds I hear. It sounded like an exhaust. Didn't seem abnormal at all.
I'm confident that I eliminated the EGR system as the cause of the problem, and even cleaned the EGR valve, but last night I drove the car to a party in DC (because it's small and easy to park) and it's as bad as it ever was. The problem is still there.
When I watch the engine, one of the radiator hoses is vibrating like crazy. The engine doesn't seem to vibrate much. At times the battery is vibrating a lot too, so you can't read the writing on it, but yesterday it wasn't so bad.
I guess it's back to the drawing board.
Under the section for vibration diagnosis, the shop manual talks a lot about road vibrations, but those don't apply because the problem is only noticed when it's stopped. The only part of the vibration diagnosis that applies is the engine speed sensitive section. They list a bunch of scary sounding possibilities:
-Belt or engine driven accessories like generator, A/C compressor, power steering
-drive belts and their tension
-bad bearings
-bent shafts
-faulty or loose flywheel
For rough idle, which seems to me like it might cause cabin vibrations and loudness, they list the following:
Sensor checks
Check O2 sensors
Check Throttle position Sensor
Check Engine Coolant Sensor
Check MAP sensor (but they don't say how)
Fuel System Checks
Check if condition occurs under Rich or Lean conditions
Check EVAP control system
Check fuel injectors for leakage
Check fuel pressure
Ignition System Checks
Check ignition voltage with spark tester
Check spark plugs for wet, cracks, wear, gap, burned, blistered, dirty
Check spark plug cables for resistence
Check ignition timing
Additional checks
Check for vacuum leaks (I did this)
Check ECM/PCM grounds for clean, tight, routing
Check ECM/PCM with scan tool to look for A/C signal
Check EGR (I did this in the post above)
Check battery cables and ground straps (battery cables look fine)
Check Crankcase Ventilation Valve
Engine Mechanical Check (It's like they are just listing engine parts now)
Motor mounts
valve timing
low compression
bent push rods
worn rocker arms
valve springs
camshaft lobes
I thought I would check the PCV valve since that was suggested. I pulled off the vacuum hose to the PCV valve, and the engine almost stalled and then started revving and then cycling between to two. When I put my finger over the end of the vacuum hose the engine settled down into its normal rough idle. It had been sucking air in like crazy.
The manual says that if you put your finger over the PCV valve inlet, it should snap back into place. I tried it and the valve did nothing. So I pulled the valve. It was perfectly clean, and I could shake it and hear the plug inside rattling back and forth. I guess the PCV valve is fine.
So then I started disconnecting the spark plugs one at a time and listening to the engine. Now I know what missing sounds like. It's very distinctive. The engine wasn't missing before. As I disconnected each spark plug in turn, the engine would sound worse each time. So I think it's not missing.
But now my check engine light was on! Disconnection a spark plug will do that. Fortunately, the CarChip Pro did exactly what it's supposed to do and I was able to turn that light back off.
So I haven't solved anything, but it's been fun playing with the pencils on the bench.
Maybe cars just sound like shit as they get older.
I pulled off the vacuum hose to the PCV valve, and the engine almost stalled and then started revving and then cycling between to two. When I put my finger over the end of the vacuum hose the engine settled down into its normal rough idle.
Understand what you did. Fuel injection monitors intake manifold vacuum. If the vacuum decreases, then the injector system assumes you have opened the throttle plate (pressed on the accelerator). So it pumps more fuel into the engine to accelerate. But then it sees the throttle not open (throttle sensor) and faster engine RPMs. So it cuts back on fuel (there is an RPM number above which injectors cut off all fuel when the throttle is fully closed). Confused because the amount of fuel to maintain intake vacuum is not desireable if you have taken your foot off the accelerator. So it stops injecting fuel. But then intake vacuum falls too much. So it again thinks you have pressed the accelerator.
Exhuast - is the sound constant? Then no "poofff" exists. Its simple. Either the sound is constant - good engine. Or is has a change (or short loss of sound) - cylinder miss. If in doubt, go around listening to other cars. Then notice, for example, how much smoother Acura, Lexus, Audis, etc are because they have higher performance engines.
Mouth the word "poofff" using lungs and not using any vocal cords. That is exactly what you are listening for. A not properly working car should make that sound.
Sensors will be seen by, for example, Car Chip as the O2 Sensor was also reviewed. MAP changes with throttle changes. The shop manual may provide some graphs that relate voltage to air pressure. Which could probably be confirmed by viewing those voltages via CarChip.
Don't know how you checked vacuum lines for leakage since that usually requires a vacuum gauge. Some lines can be tested by simple squeezing the line to learn what happens. Then comparing that line to its function defined in the shop manual.
A small vacuum leak could be apparent by temporarily plugging the offending line and its manifold connection. You saw what happened with a major leak. What would a minor leak do? The engine would constantly be searching to inject enough fuel to maintain vacuum but then lower the resulting high idle.
I do not know what they recommend for a throttle sensor. In at least one case, that throttle sensor was only factory adjustable. Any inadvertant change meant buying a new throttle sensor assembly. Don't know if that applies to your design. A precaution about doing any throttle sensor adjustments without consulting the shop manual.
EVAP system would create problems similar to a vacuum system leak. And located by similar procedures.
Low fuel pressure would result in poor acceleration. You would need a pressure gauge to measure a maybe 45 or 60 pounds pressure on gasoline. I built one once by using a water pressure gauge from Lowes and some fitting from a company selling pneumatic hose fittings. Then discovered low fuel pressure on a pump the mechanic said was good.
He could not bother to read spec numbers. He saw pressure. Then assumed everything was OK. And yes, I was pissed I had to do his job. Low pressure did not affect idle. But did restrict acceleration and eventually (but rarely) triggered the check engine light if I did full petal accleration with multiple, consecutive engine restarts. I had to create the same problem with every restart by doing a full pedal acceleration - that I never do.
Why did I find it? I would be damned if a check engine light was reported by a mechanic as an 'unknown problem'. He failed to do what all solutions require - numbers.
Low fuel pressure would be apparent when accelerating in normal mode. Pressure would be higher (and sufficient) in idle due to less fuel consumption.
Any ignition system failures would be indicated by a missing cylinder (as reported by the vacuum gauge or "poofff"). Eventually by poorer mileage. And by poor operation (ie inconsistent acceleration) during normal operation mode.
Valve timing, bent valves, low compression, worn cam lobes, valve springs, etc would result in poor normal mode operation or in noisy 'ticking' in the overhead cam. I am surprised they also did not list valve lash which is adjustable on overhead cams for better engines. I cannot think of any condition here that would cause rough idle, not create the 'missing cylinder' symptoms, but permit good normal mode operation.
Those visible vibrating parts may simply be frequency reasonant to the vibration. May stop vibrating as engine speed (and therefore vibration frequency) increases slightly.
However, is some other part (ie heat shield on the exhaust pipe) vibrating against the body only when it also resonants at that frequency? Might be heard inside but not outside the car.
Don't know how you checked vacuum lines for leakage since that usually requires a vacuum gauge. Some lines can be tested by simple squeezing the line to learn what happens. Then comparing that line to its function defined in the shop manual.
I saw in some youtube video that you can spray carb cleaner onto the exterior of the vacuum hoses. If there is a leak in the hoses or at the connections, the carb cleaner gets sucked into the vacuum hose and the engine either stalls or revs. This guy also said you can use an unlit propane torch to do the same thing. I was out of cleaner, so I used a propane torch. But it was a little bulky and hard to get into some locations. So I should try it again now that I have a pretty full can of carb cleaner.
[YOUTUBE]9CPqbaSgcok[/YOUTUBE]
Make sure it's not idling rough because the rpm is dropping too low when it's warmed up.
It's dropping down to about 700. I can't find the number anywhere for what the idle should be for a 1996 Geo Prizm Lsi, but I think 700 is in the right ballpark. It's certainly getting rougher as it drops. Maybe it should be 800? You'd think the shop manual would give me that number, but I haven't come across it in any of my reading. Maybe there is a chart of specs in the front or back or something. I should look harder to make sure that number isn't hiding somewhere.
That's not uncommon these days since the mechanic isn't required to set the idle speed. It's all the computer saying stand back, I'm in charge here. But that makes it hard to find out if the computer is fucking up because of bad feedback.
But that makes it hard to find out if the computer is fucking up because of bad feedback.
Back feedback means a computer also fires spark plugs at the wrong time.
No it doesn't. The engine management system gets input from several sources, and uses it to decide what directions to send to several components. Not all input is used to calculate all directions, only what's pertinent.
The engine management system gets input from several sources, ... Not all input is used to calculate all directions, only what's pertinent.
Pertinent to both engine speed and spark plug firing is one sensor. Typically a crankshaft position sensor or a camshaft position sensor. Computer uses that sensor to measure engine speed and determines when to fire spark plugs. How does a manifold vacuum sensor, throttle position sensor, air temperature sensor, Oxygen sensor, EGR position sensor, fuel pressure sensor, coolant temperature sensor, load sensor, or battery voltage measure engine speed?
Spark timing is a variable calculated on a shitload of conditions, and may or may not be correct depending on the information fed to the engine management system.
Hey xoB
A war of words here is battling on his turf. Here are some pictures that might help.
I've been following along, silently :facepalm:. I see a bit of :banghead: which will naturally progress to :brikwall: and :rollanim: . That's great if you want to descend to his :blah: level. Personally, I think this is :crazy:. All the :bitching: in the world won't transform a :confused: :dunce: into :idea: :thumb2:. Old and busted--:bonk:. New hotness--:mock:
Just my :2cents:
I :heartpump our favorite :robot: so :stop: :worm:ing him. Go :fish:elsewhere or :chill: and kick back with a nice cold :guinness:
I'll buy the first round. ;)
Yeah, so anyway, I've got a 4 day weekend coming. I should have some time in there to tinker a little.
My plan is to double check the engine mounts using a mirror and flashlight to really examine them. I had done the "see if the engine moves around under load" test, and ruled them out, but they are the most obvious culprit so I'm going to try to really get a good look at them.
Then I'm going to spray a bunch of carb cleaner on the vacuum hoses to check for a leak, since that's probably the next most likely culprit.
And then I'm going to look for anything that's touching the frame/body that shouldn't be.
Wish I had some jack stands. I asked for some for Christmas, so can't go out and buy any yet. It would be a lot easier to examine this car if I could raise it a bit and get under it safely.
glatt, when the car's all warmed up or whatever conditions are needed for this rough idle symptom to appear, would the roughness disappear if you gave it a tiny amount of gas? Like just enough to raise the idle, as if the idle were, say 100 rpm greater?
im, you crack me up too. not like Ron White or anything, but your own special smart funny. :thumbsup:
Puh. I got pieces of Ron White in my stool.
:lol:
glatt, when the car's all warmed up or whatever conditions are needed for this rough idle symptom to appear, would the roughness disappear if you gave it a tiny amount of gas? Like just enough to raise the idle, as if the idle were, say 100 rpm greater?
Not sure if only 100 extra rpm makes it go away, but a couple hundred more do make it go away. If it goes from 700 to around 1000, the vibrations go away.
hm.
1000 rpm is a high idle. Does the roughness diminish in a linear fashion from 700 to 1000? What's the lowest rpm that is acceptable? Maybe you have a tach, maybe not.
What I'm thinking is how low can you go to get the idle to be smooth? I don't really care about the number, I guess. If it was my car, I'd do the stuff you're doing. But if I could not find anything, I'd rig some way to get the throttle to stay in a position that let it idle smoothly. If that meant using the adjustment screw on the throttle linkage, ok. If that meant bending a bracket to accomplish the same thing, ok. If that meant putting some kind of washer/spacer in the linkage, ok. Pressing eversolightly on the gas pedal while stopped would not be ok. Something like that.
Just my :2cents:
Not to worry, I'm aware. I've made my suggestion and don't intend to pursue it, as I'm sure tw will have a solution.
I watched the engine for a while today. Can't find anything wrong. Motor mounts are fine. I used a flashlight and small mirror to look at all 4 of them very closely. Can't find any vacuum leaks. Don't see anything touching that would transmit vibrations. I listened to the injectors with a plastic pipe, and can hear them all clicking at the same speed and strength.
It sounds a little louder near the belts, and it's a throaty exhaust sound, but I can't find anything wrong with the exhaust other than a pinhole leak in the muffler that drips water. The hangers are fine.
Does this O2 sensor look right? This is a highway trip from about a month ago. I've got 4 charts from the trip.
Speed:
[ATTACH]41795[/ATTACH]
RPMs:
[ATTACH]41796[/ATTACH]
I think this is the O2 sensor up by the engine:
[ATTACH]41797[/ATTACH]
And I think this is the O2 sensor after the catalyst:
[ATTACH]41798[/ATTACH]
Shouldn't this second O2 sensor be pretty much flat? It's fluctuating almost as much as the first one.
There are no codes, and the check engine light is off.
but a couple hundred more do make it go away. If it goes from 700 to around 1000, the vibrations go away.
That is about the point where an engine changes from its idle mode operation to normal mode operation. More accurately, point centers closer to 1200 RPM. Its not a sharp transistion. But at 1000 RPM, idle mode parameters are changing to normal operation mode.
What exactly is that point? Decelerate while not touching the accelerator. It begins entering idel mode when fuel injectors go from no operation (no fuel into the engine) to providing fuel for idle mode.
Idle for most cars is 800. But again, what determines that idle? Its computer times the engine by monitoring only the crankshaft or camshaft sensor. Computer only reads that sensor to adjust fuel for 700 (or 800 on most cars) RPM once the engine is warm.
Asking if 700 is too low is a valid question. Sometimes that spec number is on a label glued under the hood or attached to the door pillar (that label covered when the door closes). I have never seen a shop manual not provide that number even when no adjustment is possible. Since a wrong number could be symptoms of a specific problem.
Anything you might do to change idle will be compensated for by the computer. So if idle should be 800, well that would imply a master clock problem in the computer. And therefore might explain roughness only at idle only because the computer wants an idle that is too low.
Well, touch the accelerator to raise RPMs up to 800 may or may not report something useful. Says little by itself. But in combination with other facts, may imply a suspect.
Shouldn't this second O2 sensor be pretty much flat? It's fluctuating almost as much as the first one.
An engine is constantly adjusting (ie short term fuel trim, timing advance) for changes you may not even realiize exist. View how stable your foot is by monitoring the throttle position with Carchip. Also see how much an engine changes with throttle and load variations (ie monitor manifold vacuum, timing advance). Simply approaching another vehicle means those parameters must vary significantly with less air flow resistance. An O2 sensor must detect changes so tiny that you do not even realize they exist. Those same changes would also appear after the catalytic converter.
O2 sensor is important during normal operation. Install a defective O2 sensor and see little to no idle mode change. Your gas mileage implies everything necessary for proper normal mode operaation (engine timing, spark advance, manifold air pressure, EGR valve operation, O2 sensor) is ideal. Concern is something different during idle mode.
For example, an EGR valve must open and adjust position during normal mode. Same EGR valve must be completely closed during idle. Same EGR valve acts completely different in the two operation modes. EGR valve could be leaking (defect during idle mode). But performs as a completely different device (100% functional during normal mode). IOW the same part has two completely different operation modes.
Your EGR tests said the EGR valve in both operation modes was OK.
O2 sensor says little during idle mode operation. O2 sensor is mostly about detecting minor changes in normal mode operation to cause minor adjustments to fuel injector fuel trim. Your mileage suggests fuel trim is just fine because an O2 sensor is accurately detecting minor changes such as your foot on the accelerator, minor change in road grade, air resistance due to the vehicle in front, etc.
How much must parameters change when you think everything is constant? Use CarChip to monitor thottle position, manifold vacuum, ignition timing advance, and short term fuel trim. Notice how much your engine changes when you think everything is constant. The O2 sensor, as Carchip shows, also reflects those variations.
Sensor readings and control adjustments vary much during normal mode operation. Those same sensors are typically irrelvant when in idle mode operation. During idle mode, a computer monitor a crank or cam sensor to measure engine speed. Then makes adjustments to the Idle Control Valve to maintain RPMs. Other sensors and control functions change little or are ignored. When entering idle mode, a part that does not operate or change during normal mode operation (Idle Control Valve) goes from doing nothing to doing the most.
Again, exhaust noise suggests no missing cylinders. A vacuum gauge would probably confirm that. 700 RPMs, although low for most cars, may or may not be too low for your engine.
We have avoided the Idle Control Valve. Nothing at this point suggests a problem exists there. However manually testing it for smooth operation (with fingers) might discover a minor problem. I seriously doubt it. But really, we are running out of suspect. And the 700 RPM number is slowly sounding relevant.
A most complicated operations occur during normal mode operation. What we have seen and what gas mileage confirms implies all those functions are OK. Idle roughness only at 700 RPMs involves many fewer sensors and parameters. O2 sensor typically is not on a list of idle mode suspects. An O2 sensor defect would be more apparent in normal mode operation. But everything we have seen implies the O2 sensor is just fine.
Don't remember if an answer was provided. Are the voltage limits for that O2 within specs defined by the shop manual? At one point I wondered if your O2 voltage variation was too much. If remembering correctly, you said it was OK.
For example, an EGR valve must open and adjust position during normal mode. Same EGR valve must be completely closed during idle. Same EGR valve acts completely different in the two operation modes. EGR valve could be leaking (defect during idle mode). But performs as a completely different device (100% functional during normal mode). IOW the same part has two completely different operation modes.
Your EGR tests said the EGR valve in both operation modes was OK.
When I checked the EGR valve, I could open and close it by sucking on the hose that goes to the diaphragm, but I couldn't see inside the valve to see if it was sealing properly when it slapped shut. Maybe there's a little grit keeping it from closing. I sprayed A LOT of carb cleaner in there so I
think it's clean, but I can't know for sure. I suppose I could have tried somehow blowing through the exhaust channel to see if it was blocked. Even after cleaning, there's no way I'd want to press my lips against that surface.
When I checked the EGR valve, I could open and close it by sucking on the hose that goes to the diaphragm, but I couldn't see inside the valve to see if it was sealing properly when it slapped shut.
That's why you kiss the ERG valve and just blow (or suck). Didn't they make a movie about that?
I have another car question. Yay!
This one is about a 2001 Toyota Camry.
We bought this car used about a year ago, and so don't know its history or what "normal" is for it. No idea if all proper maintenance had been performed because maintenance records are incomplete, but the car has fairly low miles (65k) still and it appears to be in pretty good shape.
Sometimes when driving on a highway at steady speed, I would notice a very very slight fluctuation in engine power. Kind of like a stuttering. But so minor, that I thought it might perhaps be my imagination. Except I was sure it was actually there. This has been going on for the past 3-4 months very intermittently. We buy brand name gas. This stuttering was not a big deal, because is was barely noticeable, and others in the car didn't even notice it.
Last weekend, after driving on highways for about 2 hours on our way to the beach, we got to a surface street and had to stop for a light. When it was time to go again, the car wouldn't move. And the check engine light was on! After a moment of panic, I realized the car had stalled, but I hadn't heard the engine stop because the radio was so loud. The check engine and a couple other lights were on, but went off when I restarted the car. It started fine. We continued on our way.
We had about 15 more miles to travel to our hotel, and the car was sputtering intermittently the entire way. It stalled two more times, in spite of my efforts shifting into neutral and giving it some gas as we stopped at lights. The last time it stalled, it started back up again and behaved perfectly normally for the last mile or so to the hotel.
Driving it the next few days at the beach, it behaved perfectly normally.
On the 3 hour drive back home, it behaved perfectly normally.
I tinkered with it in the driveway at home and it behaved perfectly normally the entire time.
the clues:
-There is no check engine light on, and no diagnostic codes. I assume this means the spark plugs are firing, because I think the computer would report no spark.
-It behaved a lot like a lawn mower running out of gas. Except the tank was 3/4 full when it stalled.
-The repair manual says that when you turn the ignition key to the "on" position, you should hear the fuel pump whirring for about two seconds, and then it will turn off. When I turn the key to the "on" position, the fuel pump does not run. The fuel pump doesn't begin running until I turn it to "start."
-I checked the fuses and relays that the manual said I should check, and they appear to be fine. One relay check was only a partial check though, but I swapped it with an identical relay for the horn and the horn still worked and the pump still didn't.
-I pulled out the back seat and checked the voltage at the connector to the gas pump when the key was turned to "on." It had battery voltage at one conductor and 5 volts at another. The manual didn't say what it should have.
-I saw a creepy little spider crawling around on top of the gas tank when I opened the hatch under the back seat to look at the fuel pump connector. How long had that guy been there?
So do I just go ahead and replace the fuel pump? They cost like $200 for the part, and there's also some whirlygig contraption next to them that controls them and I don't know what they cost, but they look expensive and complicated.
I also noticed that there is no little metal flap on the gas tank opening on this car. Every other car I've had has one of those little flaps under the gas cap. Could that flap have fallen into the tank and blocked something? Or didn't this car have one?
...Could that flap have fallen into the tank and blocked something? Or didn't this car have one?
Possible. Next time it does this, slam on the brakes good and hard, if that's the problem, it should clear up, for a while.
I'd start a fuel pump/fuel filter replacement fund, anyway.
Also, you might go to an Autozone, and have them check your ignition coil(s). My local Autozone does this for free. They might can tell you what those voltages you spoke of at the tank are supposed to read, too.
Also, too, FWIW Momdigr's LeSabre did not show a 'check engine' or 'something's f'ed up' light with a dead miss/no fire at the plug.
-I pulled out the back seat and checked the voltage at the connector to the gas pump when the key was turned to "on." It had battery voltage at one conductor and 5 volts at another. The manual didn't say what it should have.
Voltage to the pump typically should be 12 volts. No reason to put an expensive 12 volt to 5 volt regulator on pump power. So why is it only 5 volts?
I saw this once on another car. One transistor would not properly conduct in rare cases when it got warm. So the car would not start until that transistor cooled. Then works fine. Later I heard of a service bulletin for this problem.
That is but one example. Many reasons could explain this. But only 5 volts on what should be 12 volts is enough to concentrate on that symptom. To go further or say more requires electrical diagrams. Generally $40 from the only company that sells these books (Amazon apparently is not permitted to compete.)
All cars start same. When a switch is first placed on, then the fuel pump operates for a few seconds. You must be in a quiet area to hear it. In your case, it probably works most of the time but maybe does not work when something is too warm or has some other environmental change after long operation.
Moving on to other symptoms. For your problem to create a check engine light, you may have to aggravate the problem on multiple and consecutive restarts. For example, after each restart and when the engine is hot, floor it. Find some place (ie steep hill) to do this so that the engine demands full fuel. You may not feel a problem. But the check engine computer does. If you restart the engine only once without doing this, then you must repeat this test all over again.
A check engine light for this particular fault only lights when the same problem has been seen at least two or more times consecutively (after each restart). This problem would only be seen by a check engine light when the pump is taxed (full flow). If you restart the engine once and do not tax that pump, then the check engine light zeros its counter.
It had battery voltage at one conductor and 5 volts at another.
!2 volts to power the pump, 5 volts to operate the gage, ground to chassis.
Makes sense.
The pump not running for two seconds when the ignition key is turned to "on" is an actual observed problem. But I don't know if it's the same problem that caused the car to stall. If I track down the pump running problem and fix it, I have to wonder if that will also keep it from stalling.
I think I may need to research the ignition switch and test that next. I wonder if a problem with the switch is causing the pump to not run for those two seconds.
Meanwhile, the car runs fine on errands around town.
The couple of seconds of pump action is to bring the fuel pressure up to the range the fuel injection needs, before it even bothers to turn the engine. If it thinks it has pressure it won't start the pump.
If it thinks it has pressure it won't start the pump.
Depends. Only some vehicles monitor pump pressure. Often a two second (on some longer) pump action is only by a time delay relay or something equivalent. Without those schematics, nobody can say anything more.
If problems exist as suspected, then the 'floor it with each restart' test is essential so that the check engine system (light) can report what is defective and intermittent.
I don't see lots of other important facts such as amount of gas in the tank, engine temperature, battery voltages (ie lights changing intensity, a check of all battery cables for a loose connection, etc)
Of course you can call into Car Talk on NPR every Saturday and Sunday. They may even sell you a voodoo doll on the shameless commerce division of Cartalk.com to keep away evil spirits. That sometimes works.
When it stalled, the tank was at 3/4, and the engine was hot from driving two hours. The battery terminals are clean, and look tight, but I didn't try to move them or tighten them more. That's another thing to double check. I don't remember the battery voltage. A little under 12 volts, I think, but the engine was turned off then. The voltage would probably be higher with the alternator running.
This car's computer does not report fuel pressure. I tried checking it with my CarChip pro data logger but there was nothing to record. It has no dashboard fuel pressure gauge either. I wish it did.
I'm going to take another look at it this weekend when I get some time. Meanwhile, it's driving normally.
I don't remember the battery voltage. A little under 12 volts, I think, but the engine was turned off then. The voltage would probably be higher with the alternator running.
Voltage must be above 13 volts when running; over 12 volts when engine is not. CarChip can report this voltage.
However that voltage would not explain your problems. A loose battery connector would explain problems. Better mechanics always disconnect the battery when doing work. Sometimes attach the cable but forget to tighten it. So high temperatures longer (ie 2 hours) means the connection is not as firm.
Wouldn't the radio have cut out if the battery cable was loose? And it stalled at a traffic light while the car was perfectly still. Doesn't matter. It's an easy thing to double check.
I wouldn't associate any of that with your problem(s).
I'd focus on the fuel system.
Just sayin'.
**********************
Remember the seventies? :rolleyes: If your car didn't work right, it was a fuel/air/fire issue.
Nowadays, if it don't go, it could literally be one, or more, of 75-100 different things.
it is still about fuel/air/fire, as long as we're talking about internal combustion engines.
...
however...
when the fire is sent, when the fuel is sent, how much fuel is sent, the control of the air (via variable valve timing), those kinds of things are MUCH MORE strictly controlled, and affected by MANY, MANY MORE factors that didn't used to be considered. Those factors are evaluated by VASTLY MORE sensors, and that means lots and lots and lots more points of failure.
Yeah there's about twelve dozen electronic fuck-ups that can leave ya hoofin.
Wouldn't the radio have cut out if the battery cable was loose?
No for at least three reasons. Current required to maintain engine operation means voltage can drop too low to maintain the engine. Current required to keep the radio running would be so small as to not cause the same voltage drop. Radio will also operate for a short period of no power without interruption.
Of course that means the cable is loose only to the point that is it disconnecting (partially) with higher temperatures. However, by the time this question was posted, that suspect could have been identified or eliminated. This suspect only discussed to demonstrate how many more reasons could create your symptoms.
Suspects are not limited to fuel. Also as likely are problems with the ignition system. Or with a MAP. Significant number of suspects quickly diminish if the problem trips a check engine light. If you cannot, that also diminishes the number of suspects.
What's the resistance value for "continuity" in a relay? The manual says to check for continuity, but the meter reads 0.9 ohms when I test the meter by touching its leads, and reads 118 ohms when testing the relay's prongs. When I apply battery power to those same prongs, I hear the relay click, and the other set of relay prongs go from no continuity to 0.9 ohms. Seems like it's working, but I'd expect "continuity" to have a far lower value.
By the way, I checked the battery cable, and it felt secure, but I was able to tighten it up considerable. There's a little rubber gasket between the two sides of the clamp, and it barely squeezed before. I tightened it up until the gasket was bulging a bit.
Tried to get the check engine light to come on by driving hard, including up a hill. But it's still off.
The only thing I've found wrong is the fuel pump doesn't come on for two seconds when key turned to "on."
Less than .9 ohms. :eek: A fingerprint will give you .9 ohms, that's nothing. Sounds like the relay is cool.
Homeland security saw you were speeding and punished you by sending a signal on skynet for your car to hiccup, you know, just to scare you a little. ;)
Sounds like at this point, without throwing a ton of money at it, or making it a possibly fruitless quest, you'll have to wait for a solid failure, or at least less intermittent symptoms.
As far as the pump not giving you that two seconds, it doesn't matter as long as it's starting right up when asked.
Not the right thread, but maybe the car guru's can help me...
Each year I spray our metal heat register covers with a "refresh" coat of black paint.
This year, I used a can from last year.
The problem:
The paint on two covers are still sticky after overnight "drying" in the house.
The paint does not transfer to my hand or paper, but I'm concerned that
walking on the register may end up tracking paint onto the floors.
Any suggestions for hardening the paint now instead of later ?
Hair dryer? Coat o' clear?
Will it fit in the oven? A gas oven can be moist at low temps, but an electric would be good. Set it for 175
Thanks Griff and Glatt.
I tried the oven thing overnight and things are much improved
... still a little tacky, but it looks like it will be OK after the house heat has been on for a while.
Same issue with the car today for about 10 minutes. Then it got better.
[youtube]feV2Rwy7EZM[/youtube]
Never stalled, but almost did.
It's so bizarre that it's intermittent. It's running perfectly now. If I took it to a mechanic, I wouldn't be able to show them the problem.
My first thought was a dirty fuel filter, but I wouldn't expect that to get better.
You could show someone familiar with that type of car the video clip. They may have previous experience with that syndrome, or at least a clue where to look.
It's so bizarre that it's intermittent. It's running perfectly now. If I took it to a mechanic, I wouldn't be able to show them the problem.
My first thought was a dirty fuel filter, but I wouldn't expect that to get better.
Pfffft. Fuel filter could easily be intermittent. Do you think the crud the filter collects is uniformly fine and uniformly distributed? Unlikely. It could easily be mostly crapped up, but still have a small passage for the fuel. Then with the vibration of the engine shake loose some crud opening a wider path for the fuel.
Seriously, why not just SHOTGUN the situation and replace the fuel filter? (you're welcome tw). Worst case, you have a new filter and twenty fewer bucks. Or, it could fix or ameliorate the symptoms.
Plus tw will berate you.
Ok. I have obtained a fuel filter. And I should have time tomorrow afternoon to install it. We need an oil change too, so I'll do that at the same time.
Seriously, why not just SHOTGUN the situation and replace the fuel filter? (you're welcome tw). Worst case, you have a new filter and twenty fewer bucks. Or, it could fix or ameliorate the symptoms.
Plus tw will berate you.
He is gonna blow his top.
Quick, put on your safety glasses.
If a fuel filter is clogged, the problem is easily identified so that an intermittent no longer exists. Simply remove the filter and blow through it. Flow would be obvious restricted. Or backwash the filter with a solvent. Either means you know if a problem was or was not solved. Since you have a new filter, then blowing through the old and new filter will make any restriction obvious.
Shotgunning did not find the problem. Leaving you unsure if anything was fixed.
Or the entire fuel system could be tested without replacing or buying anything. Shop manuals may state how many pints a fuel pump will pump in a specific time. Then the pump, intake filter (inside the gas tank), pipe, check valves, and in-line filter are all verified as a complete system. IOW a problem is known solved because the problem was first seen before corrected.
Concept was taught in CSI: "Follow the evidence".
If I go through the hassle of taking off the old filter (it's buried behind a lot of stuff) then I'm definitely going to replace it with the new one. The filter is cheap.
This car has 60k miles on it. The manual says filters should be changed every 30k. It should be on its 3rd filter by now. I don't know if it's ever been changed, but I doubt the previous owner changed it just before unloading it.
Glatt, was the vehicle doing that 'surging' thing by itself, or was someone moving the throttle? Assuming it was happening without throttle input, could the throttle position sensor cause such a thing?
It was doing it by itself. It would almost stall, and then the computer would give it more gas to prevent the stall. And then it would stop giving it more gas, and the cycle would repeat.
I just finished installing the fuel filter. And now it's idling a bit fast. Haven't driven it around yet, so that might just be the cold start, fast idle mode. It was a bit of a pain. Had to remove the air cleaner assembly and half a dozen vacuum hoses and sensor cables to get at the thing. Frankly, I'm pretty proud that I got it all back together and working with no leftover parts.
This car has 60k miles on it. The manual says filters should be changed every 30k.
I would change gas filters, air filters, PCV valve, and spark plugs as recommended. Eventually learned that was mostly unnecessary. But again, if a filter is the problem then blowing through it would make the problem obvious.
Eventually I stopped replacing spark plugs, washed the PCV valve in a solvent, banged the air filter on asphalt to clean it, and never replaced a fuel filter.
Generally, idle is not controlled by the throttle (as that picture shows). An IAV does idle air adjustments (a problem discussed with Cloud? when a Honda that mechanics refused to solve it until another mechanic was used). To say more requires facts from the shop manual.
How to eliminate fuel as a suspect was defined. Air leaks might be found by using vice grips to restrict any hose the manifold. Learning how to examine the EGR valve as a suspect would be useful. Just a few of so many suspects (maybe 50) can create an unstable idle; best identified rather than replacing (shot gunning).
I have long forgotten what is the car, what all symptoms are, what was tried, etc. However you have learned from reading the shop manual how many suspects are on the perp list. A list so long that shotgunning can get expensive.
Pictures are always fun.
This is what it looks like when I start to replace the fuel filter. You can't even see the damn thing, but it's down there.
[ATTACH]45855[/ATTACH]
When I lean in a little closer, you can see the banjo bolt at the top of the guy under there. There is no way I can get my hand in there, even from below, to remove the thing. Well, maybe from below, but the last thing I want is a face full of dripping gasoline when I open the fuel lines.
So here's the filter, and what I need to remove to get to it.
[ATTACH]45856[/ATTACH]
Here it is, with the entire air assembly removed, and half a dozen hoses and cables detached to be able to get to it. Notice I put blue masking tape on everything and numbered them so I could keep track of where it all goes when I put it back.
[ATTACH]45857[/ATTACH]
And look at all the room I have to work with now! I actually had to halfway remove the bracket holding the thing so that I could get the lower (rigid) fuel line to align with the new filter.
[ATTACH]45858[/ATTACH]
It was all pretty straightforward, but took about two hours, including getting all the tools out and putting everything away again.
We're waiting for the denouement.. did you fix it ?
Beats me. I replaced the fuel filter. Didn't take a picture of the new one. The pictures were for reassembly reference and not so much for sharing on the Cellar. That was just a bonus.
It was an intermittent problem that went almost exactly a month between showing up the last two times. We'll see if it happens again between now and Thanksgiving.
...that went almost exactly a month between showing up the last two times.
You've neglected to mention, but, uh, ahem -
is this car a female, by any chance?:eyebrow:
Beats me. I replaced the fuel filter.
An answer is simple and immediate. Blow through the old filter. Is it restricted? If not, then it did not solve the problem.
Oh, yeah. There was more resistance blowing through the old filter, but it wasn't dramatic.
Oh, yeah. There was more resistance blowing through the old filter, but it wasn't dramatic.
So a new fuel filter did not solve anything. An original and still 'wet with fuel' filter might explain a slight restriction. It would not explain fuel restrictions during idle.
Imagine what happens when the car was actually demanding much fuel. Idle demands little. Heavy acceleration requires plenty of fuel. The engine would obviously stumble and almost stall on acceleration if that filter had any relevant obstruction (was dirty).
An intermittent problem can be created by many things that exist constantly. For example, if a fuel pump pressure was slightly low, then the car would work normally almost all the time; only have intermittent stumbling.
The EGR valve would not move smoothly. But the car would work normally almost every time - just not in the rare time when the EGR valve intermittently stuck. Move the valve by hand to feel the restriction that only rarely gets stuck. Unfortunately intermittents not reported by the computer can be this difficult to locate.
Distributor vacuum advance and retard motion can also be intermittent. In one case, I discovered that intermittent was created by grease on those moving parts that had become sticky with age. It always existed. And was located by physically moving the part by hand. The sticky grease always existed. But the resulting bad performance only occurred rarely and without any one common action making it happen. Intermittents are that nasty to find when computer diagnostics do not report them.
As you recall, shop manual provides a list of suspects that are numerous.
BTW, the engine is almost two completely different engines when in idle and when moving the car. Many parts do completely different operations in those two modes. Another way to eliminate suspects from that list. That was the case in cloud's IAV failure. Only the 'idle' engine was failing. The 'moving the car' engine worked just fine.
Two months without a problem. Convinced the fuel filter fixed it. Then it was doing the same sputtering today that it was doing before. No time to trouble shoot or look at it. Got to my destination. Shut it off for about 5 minutes, and it's been working fine since then. Such a weird intermittent problem. But it's fine now, so *shrug*.
I guess I know now why the previous owner parted with this used car.
Try writing down all the conditions/details you can come up with each time it happens.
-how long you have been driving it
-distance
-time of day
-amount of fuel
-engine temp
-ambient temp
Maybe you'll see a pattern that hasn't emerged just yet.
Yeah. I need to ponder this.
Yeah. I need to ponder this.
Demonstrated was why shotgunning does so poorly at eliminating problems. So what has changed? As Gravedigr suggests, collect facts. List every part that was touched (not just moved- touched) when you replaced a filter. What has been touched recently? Not when the intermittent occurred. But even a week previously.
The number of possibilities is literally approaching 1000. No exaggeration. Good diagnostic procedure means reducing that suspect list to more like 100. Which is why replacing the filter only on speculation was so unlikely to be the defect. Especially if blowing in the old filter did not expose a restriction. And since a restricted filter only causes problems on acceleration - not at idle.
Imagine a wire of 32 strands. All are broken. Move that cable and some remain in contact. Move the cable and too many are disconnected causing confusion to the computer or insufficient power to a solenoid. Replace a solenoid. That new one might work with two less strands connected. But the problem still exists. Just fails less often. Only symptoms cured.
Above demonstrates what you are dealing with. Previously listed were how to eliminate some more common suspects (ie EGR valve, vacuum advance and retard system, intermittent manifold leak or defective idle control valve, partially broken cable, dirty connector that gets cleaned by making and breaking and then fails months later because the reason for that corrosion was not identified and eliminated, etc).
Well, one symptom that eliminates some suspects is temperature. Apparently (does?) temperature is unrelated to good and bad operation. Has fuel been eliminated as a suspect - were consecutive tanks from the same station or brand? When the intermittent exists, what exactly do you do to make the problem repeatable or make it worse? Do lights change intensity? Do tires make more noise? Irrelevant is a belief that tires are irrelevant. Solving intermittents means collecting all facts irregardless of whehter you believe it is irrelevant. BTW, that is a repeated concept so accurately expressed in a TV show called House.
I routinely get called when others cannot solve strange problems. Many never learn that this is critically important. Collecting facts and symptoms is completely unrelated to identifying the problem. Which is also irrelevant to what comes later - eliminating the defect.
As I said without exaggeration. Your list of suspects is somewhere approaching 1000. Getting that number down means collecting facts as Gravedigr noted. And then identify a defect long before replacing any parts. Yes, even strange noise from tires in rare cases can be the kicker that identifies an intermittent engine problem.
... Solving intermittents means collecting all facts irregardless of whehter you believe it is irrelevant. ...
[bold mine]
Eloquently said.
The weather was finally nice enough yesterday for me to work on the car. Except of course, Murphy's law said that I was booked solid for most of the day with other stuff. I only had about half an hour in the late afternoon to look at it.
But I found a problem.
I wanted to start by pulling the spark plugs and looking at them so see what shape they were in. Then I wanted to get a spark tester to check that there was a good spark at each plug.
The car is 12 years old, and I was concerned that the plugs might be hard to remove. I had read about some guy on the internet who tried to check his plugs, and one broke off during removal, leaving threads locked in place in the cylinder head. That would suck, and I wanted to avoid that. So I planned ahead by switching the cars in the driveway so I could use the other one all day running errands, and the Camry engine could get nice and cold. Cold metal shrinks. I also went to the parts store to get the proper sized spark plug socket and an extension, and I got an ignition tester. I squirted a little PB Blaster down into the spark plug tubes about 5 minutes before I tried to loosen the plugs.
So it was time. I pulled the wires off the first plug, put the socket on the extension, attached it to the ratchet, and fed it down into the tube and onto the plug. I tentatively started to push on the wrench, and the plug started unscrewing with almost no effort at all. It was about as hard as unscrewing a light bulb.
I pulled the plug out. It was wet from the penetrating oil I had sprayed in there. But it looked like this:
[ATTACH]46540[/ATTACH]
There's a little carbon build up, but I don't know how much is normal. Each plug looks like this.
The thing that took too long to jump out at me though, is that it's the WRONG spark plug. This car is supposed to have special plugs with two grounding electrodes. One on each side. This 5S-FE engine takes the NGK BKR6EKPB11 spark plug. It's a special metal with two prongs, not your standard single prong. Plus, these plugs were so easy to get out, I think the previous owner had changed the plugs not too long ago and put the wrong ones in.
So then I checked the spark with the tester. This is basically a fake spark plug that you stick into the end of a plug wire and ground against any convenient grounding point. I'm not sure how you're supposed to perform this test. With the engine running, or starting it up each time after making the connection. Anyway, I did it with the engine running, and even without completing any circuits with my body, I was getting zapped while trying to plug it in to the spark plug wire with the engine running. I put on an extra pair of rubber gloves over the nitrile gloves I was wearing, but was still getting a shock through those gloves. It was kind of comical. But anyway I saw consistent sparks in the tester at each wire and they looked equally strong to me. But what do I know? It's the first time I've seen sparks, and I'm not sure how they are supposed to look.
So now two questions:
1. I was running the engine for a while with various spark plugs disconnected. The engine obviously ran poorly during this time, but it was nothing like the way it behaves when it's about to stall. The weird thing though is that the check engine light never came on. You'd think the computer would be pissed off about no spark in various cylinders over a 5 minute time frame, but that light never came on, and no codes were reported. It that a problem?
2. Would the wrong spark plugs with only a single grounding electrode instead of the dual grounding electrodes cause the intermittent stalling problem? The manual said using the wrong plug would result in poor engine performance, but I figured it would be consistently poor, not intermittently poor. I didn't put the correct plugs in yet. Too late in the day to go out and track them down and I was losing light. But I'm definitely going to get the correct plugs and put them in.
Oh, and the voltage was maybe a little high?
12.75 at the battery with the engine off, and 14.75 with the engine on and alternator running. Later after the engine warmed up, it was 14.55 with the engine on and alternator running.
That plug looks good, it is burning properly. I would replace the wires and plugs just because, and drive that car until till the wheels fall off. I would check the cold start injector for function. Go to the library and get the Chiltons Manuel for that car it will tell you the proper diagnoses procedures for the fuel injection and other systems. Do not use Haynes books they don't tell you anything about trouble shooting.
That plug looks good, it is burning properly.
Thanks. It's nice to have a second set of eyes looking at this.
Spark plug tester really says little that is useful. Same could be learned by connecting to spark plugs mounted atop the engine. Crank the engine (someone else inside) while observing plug spark. Each spark will be strong and obvious.
Ceramic around the center prong should not have anything caked on it. Problem is if carbon has formed that would short the center prong to plug's metal - a path that would not create a spark. Carbon means the engine is eating oil.
More problematic would be a spark plug of the wrong heat range. You cannot test for that. Strange, but when I tried various heat ranges, it did result in poorer operation. In the days when normal was for an engine to leak oil, we would use a plug of one heat range higher. This burned off oil but also caused the engine to run poorer.
I have seen where another manufacturer's equivalent plug did cause some lesser performance. IOW I had trouble with an AC Delco equivalent. Ended up replacing the NKGs.
Since those days, we no longer replaced spark plugs. Electronic ignition and better machined engines eliminated spark plug replacement.
Since plugs are out, then just replace them with new ones. Plugs are cheap. Nothing can properly test a plug and what is important - its heat range.
Two electrodes or one makes little different. At one point, scam manufacturers were one hyping a superior design. In reality, the plug only creates a spark across one path - not matter how many other paths might exist. However using only various plugs recommended by the manufacturer has (in a rare case) proven important.
Be very careful about restoring plugs with proper torque. Over torquing is why plugs break off, strip threads, or seize in an aluminum block engine.
Why does my hemi have two plugs per cylinder?
Is that what the kids are calling it these days?
Why does my hemi have two plugs per cylinder?
Part of making a 70 Hp/liter engine involved the swirling of fuel inside a cylinder. So that an ignited flame did not slam directly down on the piston. But instead swirled down. This even scoured and burned condensing fuel from cylinder sidewalls.
A best way to accomplish this used four valves per cylinder. Another technique was to trigger an ignition with multiple plugs. A technique also implemented in Wankels. Some designs would even stagger when plugs fired.
None of that is relevant to his spark plug inspection.
Oh, i looked that up after I asked it. What I found said it fires the second plug during the exhaust stroke to clean up its emissions.
That's interesting. I learned from the manual that this Camry has a wasted spark system, which means the park plug fires twice. Once to ignite the fuel, and once during exhaust with the piston at the bottom. It didn't specifically say this was for emissions, but that's a fringe benefit. This wasted spark ignition system does away with a distributor, which supposedly makes the engine more reliable. The computer controls it all based on input from the camshaft sensor and crankshaft sensor.
But anyway, progress last night. Things came to a head. The car started misfiring and the check engine light came on! Misfire in cylinder 4. The idle dropped down to around 500 like it had been doing. So what I think happened was that I made whatever the problem was even worse by pulling the plugs and reinstalling them. That makes me think it's a spark plug wire. I had ordered new plugs and wires yesterday, and will replace them this weekend, after we get back from a funeral (my aunt's) in NEPA. If the plugs and wires don't fix it, it's probably the 1,4 coil/igniter. I think it was gravdigr who said way back in the beginning that it was a coil. We shall see.
The car started misfiring and the check engine light came on! Misfire in cylinder 4. The idle dropped down to around 500 like it had been doing. So what I think happened was that I made whatever the problem was even worse by pulling the plugs and reinstalling them. That makes me think it's a spark plug wire.
It could be a spark plug wire or even electronics that drive that wire. Or a cracked conductor inside one plug.
Remove that spark plug. Leave it connected to its wire. Somehow mount it to the engine. Crank the engine. Observe spark on that plug. A defective spark will clearly be evident and diminished. A weak spark drives an engine normally most of the time. But that spark could have always been defective.
To appreciate a good spark, remove another plug to perform the same test. That spark will be fully formed or clearly diminished even when only cranking its starter.
If a clearly diminished spark does not exist, then move things to make a defective (weak) spark. Even freezing the spark plug before connecting it to test may expose a cracked conductor inside the spark plug.
Keep hands clear. Pre-electronic ignitions created only 20,000 volts. That hurt. Don't learn like I did. Electronic ignitions create higher voltages and greater current. Best is to use something like vise gripping pliers to hold or prop that spark plug against its engine block. A spark can even penetrate through heavy insulation on a spark plug wire. Do not even touch the wire.
Normal is for a computer to see a weak spark and not report it until after multiple engine restarts or some other conditions. Since reporting too many intermittents every time causes many mechanics ignore all error codes.
What I found said it fires the second plug during the exhaust stroke to clean up its emissions.
Cleaning up emissions is also increasing gas mileage and horsepower.
While waiting for the new plugs and cables I ordered, I went out and checked to see if the car is still messed up.
This is the spark plug wire at cylinder 4. Look at the spark shooting out the side of the wire. No wonder there is a misfire.
[YOUTUBE]4K4qUQBMusM[/YOUTUBE]
Yah. That's not supposed to happen.
Look at the spark shooting out the side of the wire. No wonder there is a misfire.
For future reference. Inspecting that wire at night with the engine running would have identified the fault. An example of identifying a defect before it creates a failure.
Two electrodes or one makes little different. At one point, scam manufacturers were one hyping a superior design. In reality, the plug only creates a spark across one path - not matter how many other paths might exist.
I asked one of the Champion applications guys, he said exactly this.
I read somewhere that with the two electrodes, the spark prefers the narrower gap and stays on that side until the gap widens over time, and then the spark switches over to the other gap, because now it's the narrow one. It alternates like that as the gaps wear over time.
Since this plug fires twice per cycle in this wasted spark ignition system, it wears faster than in an engine that fires once per cycle, and having the two electrodes makes up for that quicker wear.
That's what I read, anyway.
Keep hands clear. Pre-electronic ignitions created only 20,000 volts. That hurt. Don't learn like I did. Electronic ignitions create higher voltages and greater current. Best is to use something like vise gripping pliers to hold or prop that spark plug against its engine block. A spark can even penetrate through heavy insulation on a spark plug wire. Do not even touch the wire.
There are many tools designed just for this purpose. They are all dirt cheap, and they all beat the shit outta getting hit by that ~60,000 volt jolt.
Do not grab that wire or plug with Vise Grip pliers.Yeah. I was shaking my head at that one too.
Using a powerful conductive tool to crush a high voltage component. Damage it and get a shock too. :headshake
Using a powerful conductive tool to crush a high voltage component. Damage it and get a shock too.
Necessary for testing is to hold a spark plug to the block. Also noted was to not use hands to hold anything. Why would anyone assume vise grips are held by a hand? Pliers obviously hold a spark plug to the block so that a human does not. And so that the better test will work. Obviously something that is not human must hold a spark plug in contact with the block. Why would anyone assume otherwise?
Using vise grips was a best solution that obviously does not cause damage. What was obvious should not need explaining. Something must hold a spark plug's steel body to engine block steel. Why would anyone assume a human holds anything?
Two electrodes per plug was a sales gimmick decades ago. And obviously a sales gimmick today. A spark will cross only one gap whose distance is less than defined by voltage. Irrelevant is it using alternative electrodes. Because a spark only crosses one gap with each spark - meaning it works just like a single electrode spark plug.
Scam manufacturers once hyped spark plugs with multiple contacts. It did nothing useful. More important than multiple contacts is a plug's heat range. Integrity of its ceramic insulator. And how to install it at a proper torque. Did a salesmen forget to mention other and more important parameters to make a sale? When spark plug voltages were so low (ie 18,000 volts), then a spark's gap was important. Today, we no longer need adjust gaps to within 0.01 inches.
Spark plugs once required frequent replacement since metal was of lower quality. Spark plugs are now made using higher temperature metals meaning plug wear and replacement is now rare.
Why would anyone assume vise grips are held by a hand?
maybe because they are classified as HAND TOOLS?
what tiny shred of credibility you ever had is now gone. between this and the tits.... jesus. get help
Use 2 spring loaded clips of a size that will fit the plug, some insulated wire. Clip to plug and ground. I have one in the shop I've used for years on lawn mowers. No. No photo today. :bolt:
maybe because they are classified as HAND TOOLS?
They are vise grips because the tool is attached and left untouched. Can you be any more stupid? Please try. Is this totally justified insult of your intelligence simple enough to comprehend? Sorry. The word has ten letters. Do you understand it? Electricity has eleven letters. Apparently that is confusing.
For others: Lumberjim posts insults because he knew Jeeps are better on slippery roads. He said he knows because he feels it is true. Facts that exposed his myth make him angry. He cannot accept that myths and hearsay so easily manipulate. So the emotional Lumberjim constantly posts insults like an adult thinking like a child.
Any idiot would not hold 20,000 volts with a metal tool. Clamp it in place with a hand tool such as vise grips or a clip. So simple to grasp. But the fewest, such as Lumberjim, fear to learn. Then get angry and post insults.
Don't like "The TW Treatment" I see.
Why would anyone assume vise grips are held by a hand?
Let's try this, please post a pic of what you think Vise Grips are.
Cuz, the rest of us are talking about this;
[ATTACH]46598[/ATTACH]
Please to note it is a ƒucking
hand tool.
And if that is what you were referring to, you obviously know fuckall about tools.
Let's try this, please post a pic of what you think Vise Grips are.
So where is the hand? Not touching the vise grip when those pliers are holding a spark plug to the block. Why should the obvious be explained?
So where is the hand?...Why should the obvious be explained?
Demonstrated here is a question to answer your first question: What, do you think they attach themselves by way of magic? Mental telepathy? No wonder you are confused.
Second question addressed: Because you often appear to know something about which you post, and, at this time, you appear to be an idiot.
Leave it as you will, but, don't try to make those of us who know what we're talking about look dumb just because you spoke out of your ass about something you don't seem to comprehend. And refuse to understand.
So where is the hand?
It's right
here.
Aaaaand you don't know how to post a picture.
I'm done, now.
Aaaaand you don't know how to post a picture.
Wow. You are so easily made emotional. Meanwhile 1) vise grips hold a spark plug to the block while the hand is inside the car turning the key. Did you think about that? 2) Vise grips clamped to the engine block mean vise grips are at zero volts. Did you think about that? 3) Vise grips holding a spark plug to the block means no hands need hold the vise grips. It is so simple that even a child can comprehend it.
BTW, be very careful to not take a piss using vise grips. Should you need that explained, then just ask.
They are vise grips because the tool is attached and left untouched. Can you be any more stupid? Please try. Is this totally justified insult of your intelligence simple enough to comprehend? Sorry. The word has ten letters. Do you understand it? Electricity has eleven letters. Apparently that is confusing.
For others: Lumberjim posts insults because he knew Jeeps are better on slippery roads. He said he knows because he feels it is true. Facts that exposed his myth make him angry. He cannot accept that myths and hearsay so easily manipulate. So the emotional Lumberjim constantly posts insults like an adult thinking like a child.
Any idiot would not hold 20,000 volts with a metal tool. Clamp it in place with a hand tool such as vise grips or a clip. So simple to grasp. But the fewest, such as Lumberjim, fear to learn. Then get angry and post insults.
you mad, bro?
Clip one end to spark end of plug other to ground.
Oh, glatt, I'm pretty sure tw just called you an idiot. Just sayin
Oh, glatt, I'm pretty sure tw just called you an idiot. Just sayin
The only idiot is the guy who posts insults because he cannot read. That is you, bro.
Changed the plugs and wires, and it's working well now. Or at least for the 2 minutes I let it idle. We'll see how it does after running errands.
I suspect that the intermittent stalling problem was a separate issue, and may crop up again. But after considerable research, I suspect that the engine coolant temperature sensor is the culprit. Apparently a lot of Camry owners have had this problem and fixed it by replacing that sensor. But there's an easy test. If the problem manifests itself again, I just unplug that sensor. If it gets better, it was the sensor, and it needs replacing.
Yesterday I switched out the engine coolant temperature sensor. The car had been behaving normally for a few weeks, but based on my research and questions at a Toyota repair forum, I think an intermittent fault at this sensor was causing my stalling problems, and the bad spark plug wires were just a coincidence.
So I let the car cool off so I wouldn't burn myself on the coolant gushing out when I removed the sensor and quickly inserted the new one. And I made the switch.
New:
Old:
The old one has a copper washer, did the new one?
Nope. Coolant was gushing out of the hole when I pulled the old sensor out, and I didn't notice the old washer until after I got the new sensor in and saw the shiny washer had been flushed away onto the transaxle or something. I had lost roughly a cup or two of coolant, and didn't want to lose even more putting the washer back. I put plumbers tape on the threads of the new sensor, and it's not leaking, even after running the engine for a while.
I mopped up the spilled coolant with a rag the best I could, and hosed the rest away with plenty of water.
But after considerable research, I suspect that the engine coolant temperature sensor is the culprit.
If the sensor was defective, then charts from the Car Chip for that sensor would make the defect obvious. The sensor would report engine temperatures that make no sense. Or that change suddenly.
I never got a car chip report from that sensor that also happened at the same time the symptoms were occurring. The car chip is neat, but it can only track 4 things at a time. If you pick the 4 wrong things to track, it doesn't help you. When I did watch the temperature, it was normal and the car behaved normally. That's the big difficulty with this intermittent problem. How can you study a problem if you can't recreate it consistently? After I had settled on this sensor being a problem, the car behaved perfectly, so I couldn't test the theory by just unplugging the sensor when the stalling happened, and seeing if the car improved.
But I did check the resistance of both the new sensor and the old sensor at room temperature, and they didn't match. I played with the old sensor by running it under hot water, and it was cool watching the resistance change as the water got hotter. So the old sensor did something. Not sure if it was the right thing.
I'll tell you this though. My wife was talking about selling the car if this kept up much longer. So I didn't have the luxury of doing nothing and just waiting for the problem to happen again so I could study it some more. A $30 educated guess is OK with me. Better than losing thousand by having to get rid of the car and find a new one.
Based on a few different posts at Toyota Nation, where people had this exact same problem, and the ECT sensor was the culprit, I'm fairly confident this is going to fix it. We'll know if the car doesn't stall before the end of March. 2 months is the longest it ever went without stalling. I may be eating my words. We'll see.
I'll tell you this though. My wife was talking about selling the car if this kept up much longer. So I didn't have the luxury of doing nothing and just waiting for the problem to happen again so I could study it some more.
What!!! She wants to take away your fun?
How do you know if it's critical to replace tires if there is plenty of tread left? When we bought this car over a year ago, the tires looked like this, and we have been driving around on them since then without incident. Mostly city driving. Occasionally highway.
I'd like new tires, but 4 new ones of respectable quality will cost about $650-$700 installed, so I only want to replace if necessary.
See the good tread? See all those little cracks? They all look like this. Are they ok?
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OK, do you expect that I'm better off ordering them from Tire Rack online and paying to have them installed, or do you think I'd get a better deal just going to a tire place? Obviously, I can make some phone calls to compare prices, but if you have insight, I'd be curious.
I'd probably choose Michelin Primacy MXV4 tires because Consumer Reports rated them highest, and they are about the same price as other top tires.
I'd order them, and take them to walmart for installation. or pep boys... tire sales are the life blood of many retail service centers. I got my Nitto Dura Grapplers from DiscountTiresDirect, had them shipped here, to my work, and got them installed. I buy the 2nd best tires, unless the price drop is minor... in which case, I buy the best.
Crap... my tires look like glatt's, I didn't realize they were that bad off. How long are tires normally supposed to last? The car is only 18 months old. Is it because it came with cheap tires to begin with?
depends on your weather too... and the tires may be much older than the date they were installed. You gotta check that when you buy them... .make sure they aren't already 3 years old.... and then if you live in a hot dry place, keep them protected with Tire Dressing or Armor All or something.
Yeah, it's probably time to replace all four. Do you have an opinion on Michelin Energy Saver A/S tires? That's the one the Lamb's tire guy is recommending based on how frequently I commute to Houston and back. (I'm at just under 30,000 miles in 16 months...)
whook. that's a lot of driving. I'm not a tire expert... but in Houston... do you need an All Season Tire? what kind of car is it? year, make, model, sub model... engine type, please..
2012 Toyota Sienna, I think it's the LE--it's the lowest available package, whatever that is. I don't know what kind of engine, V6 I assume?
The base Sienna has 17" tires, but the AWD version has 18". both have TPMS.
The Michelins get mostly good reviews.... I love my Nittos...
here's one for your car... no reviews, but they get A ratings...
Consumer Reports ranks the Michelin Energy Saver A/S as the best for all season mpg tires.
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And these are the rankings for regular tires. There's some overlap with the gas saving tires.
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But the Michelin all season at only rated to 118 mph.
True. The Primacys are rated at 130 mph and get an even higher score.
When is the last time you drove 118 mph? Is speed rating on an all season tire really a top concern?
No.
You should seriously consider replacing the original tires on the car with a tire that has the same speed rating. The manufacturer presumably knew what they wanted on the car.
When is the last time you drove 118 mph? Is speed rating on an all season tire really a top concern?
Monday.
No.
You should seriously consider replacing the original tires on the car with a tire that has the same speed rating. The manufacturer presumably knew what they wanted on the car.
You're right, not a top concern, for everybody except xoB. I think a better guide for tire replacement is how you use your car. You've said as much yourself; no cars come equipped with snow tires, yet they're the right tire for the job, irrespective of the speed rating and original equipment.
The way I drive in my current car, nothing close to 118 mph is needed, so that's an irrelevant condition for me.
Exactly. A guy tried to sell me z-rated tires for my S-10 pickup.
Hell, that thing cut engine spark at 94 mph.
Yeah, it's probably time to replace all four. Do you have an opinion on Michelin Energy Saver A/S tires? That's the one the Lamb's tire guy is recommending based on how frequently I commute to Houston and back. (I'm at just under 30,000 miles in 16 months...)
Just taken the Dodge! to the shop, 25K miles in a year almost to the day.
I just passed 40K on the Fit in 26 months, so that's 45K a year between the two!
At least you'll drive them into the ground before they have a chance to rust.
Based on a few different posts at Toyota Nation, where people had this exact same problem, and the ECT sensor was the culprit, I'm fairly confident this is going to fix it. We'll know if the car doesn't stall before the end of March. 2 months is the longest it ever went without stalling. I may be eating my words. We'll see.
Did I mention that the car stalled again about two weeks ago, a month or so after switching that sensor?
So I widened my search of potential problems. I tried to take the Idle Air Control valve off to check it and possibly clean it. I had trouble because the phillips head screws are difficult to reach, and lock washers make them very hard to remove. I could feel that I was stripping them, so I stopped. Instead, I took off the entire throttle body, to which the IAC vavle was attached. Brought it inside, clamped it in my bench vise, and used vice grips to remove those now slightly stripped phillips head screws. I took the IAC valve apart, and cleaned it thoroughly. Also cleaned the throttle body. Both were a little dirty but not too bad.
Then I replaced the air filter. I had thought it wasn't dirty, but when I compared the new air filter to the old, the old was clearly pretty dirty.
A week went by with no stalling, but the cold start up idle is slower than it should be now. It's at about 800, which is normal for warm idle, but pretty slow for cold idle. Once it warms up, the idle stays at 800 and feels good. I'm hoping it's just that the computer needs to learn how to react to a clean IAC and it will fix itself after a while driving it.
Then on Sunday, I pulled the Exhaust Gas Recirculator to make sure it was clean. It was slightly dirty, but not bad. The valve seemed to open and close properly. But I cleaned it anyway and it's really nice now.
I keep being impressed with myself when I take all this stuff apart and put it back together and the engine fires up.
I think now I just drive it around for a while and see if it stalls again. It seems to go a month or two between stalls.
One thing I recently realized is that it only stalls for me. Something about the way my wife drives doesn't seem to bug it. So either my driving style is really hard for it, or moving my seat back sends some sort of electric signal to fuck it up, or perhaps most likely, my key chain is too heavy and it's messing up the ignition switch intermittently. How do I test for that? Wiggle the keys when it's stalling?
[ATTACH]46933[/ATTACH]
take all that crap off the key and drive it with only the key in the ignition switch.
If it were the ignition being befouled by your key, wouldn't it be more of a go or no go situation? I mean, the car would be either on, or off, no intermittence?
That's what I'm wondering too.
I would think it would be either on or off, unless I'm going over bumps or something, and then it might flicker. But the stalling/very low idle issue is most noticeable standing still. Where I think it would be on or off, not flickering. So I think it's probably not keys in the ignition. It can't hurt to jiggle them next time it's acting up. I also plan to unplug the throttle position sensor next time it's acting up and see what that does.
Hopefully the clean air filter and throttle, IAC valve, and EGR valve cleaning did the trick.
Maybe the car starts okay with the weight on it, but when he swings around a corner or goes over a bump, the added strain is enough to kill it? Edit: Okay, maybe at idle, the long vibration is what eventually shakes it loose? I dunno, I'm pulling stuff out of my ass here. But the fact that it never stalls for your wife, only you, seems to me to be a very important piece of information.
I agree with V, just separate the car key from the keychain for awhile. Easier than surgically shortening your legs to keep the seat forward, anyway.
I dunno, I'm pulling stuff out of my ass here.
Congratulations, you are now as qualified as most professional mechanics.
:D
I think now I just drive it around for a while and see if it stalls again. It seems to go a month or two between stalls.
So what was Car Chip monitoring? And what did Car Chip record with the stall?
The thing that jumped out to me with the data from this "stall" was that the voltage was fluctuating a little bit on this trip in a way that it doesn't normally. Almost like the alternator is flaking out on me.
Here is the data from the trip when it *almost* stalled. At the point of the green arrow, I was stuck behind some slow cars, and felt the engine stumble. Because I was still moving, I didn't want to shift into neutral and give it gas, but I also couldn't give it gas without rear ending the car in front of me. It almost stalled, and in fact the oil light even came on because the engine was going so slowly the oil pump wasn't pumping hard enough. A couple other lights came on too, but they all went out a moment later. When we came to a light and stopped a couple blocks later, I shifted into neutral and gave it some gas throughout the red light. I repeated this behavior for the next couple minutes of the trip.
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[ATTACH]46983[/ATTACH]
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And this is the voltage. In other trips, the voltage remains steady at around 14 volts, but on this trip, it was fluctuating. You would expect it to drop a lot when the RPMs went down to 200 or so, but it was dropping even before then.
[ATTACH]46985[/ATTACH]
Just for comparison's sake, this was a trip in the car the previous day, and the voltage then.
[ATTACH]46986[/ATTACH]
So what could cause intermittent voltage changes? If the alternator intermittently craps out, what's causing that? I don't hear any belts slipping and squealing, so I doubt it's that.
Voltage regulator? Alternator diode(s)?
I don't know much about alternators. I'll need to read up. Assuming the alternator is the problem.
And this is the voltage. In other trips, the voltage remains steady at around 14 volts, but on this trip, it was fluctuating.
Voltage in that last attachment (18 Feb) is ideal voltage for all vehicle electronics. Ideal voltage is typically anything from 12.6 to 14. Apparently voltage is a little higher (maybe 14.5) on 18 Feb implying the battery required more recharging current. Which is the alternator working just fine.
On 19 Feb, the first thing that concerns me is the idle dropping to less than 750 RPM. That should not happen. At 750 RPM and lower, the alternator really does not output much current. In fact an alternator often outputs near zero current if RPMs are well less than 800. (BTW, maximum output current starts at maybe 1500 RPMs which means racing an engine any faster does not recharge a battery any faster).
A sudden marked voltage drop on 19 Feb could be a drop much lower than the graph indicates. But that typically would not cause problems as long as voltage remains above 9 volts. Battery (without alternator) should provide enough power. However, is there any reason why neither alternator nor battery maintains above 9 volts? One possible reason is an intermittent ignition key switch. Or an intermittent relay that should but does not hold battery connected.
500 RPMs is a defect. During those 500 RPM periods, was the engine not surging or stumbling? Fact that the engine idled at 500 RPMs is itself an engine defect even if the engine did not stumble. A perfect example of viewing a 100% defect even though the engine appears to be working just fine (not stumbling).
So an interesting question. Is low voltage somehow causing the engine to idle below 800? Or is idle below 800 causes a significantly lower voltage? An example of trying to solve a closed loop system.
I had
ordered an LED light array meant to go in your car's trunk instead of the little wimpy incandescent light bulb that came with the car originally. It uses less electricity than the old incandescent and is much much brighter. Pretty cool, actually. Only $4 on Ebay.
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Installation was easy. You just take out the old light bulb (quickly before it has a chance to heat up and burn your fingers.)
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And then put the appropriately shaped light bulb adapter into the socket. Connect the light array, peel off the adhesive backing and stick it to the underside of the trunk. The light output is pretty impressive.
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So bright, and uses less power.
But I was too smart for my own good. Apparently the Camry has a circuit board in the back that checks the resistance of the light bulb circuits, and if they go outside certain parameters, it turns on a warning light in your dashboard that your tail light is out. The resistance is so low on these LEDs that the circuit board thinks there is a problem. I'm getting a warning light on the dashboard.
...I'm getting a warning light on the dashboard.
:mad:
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:mad:
With the trunk closed, and the light off, the Camry is concerned the bulb may be bad? WTF? :confused:
I think it has a memory. I popped the trunk with the engine running the other day, and the light came on shortly after.
I dunno. I checked all the tail lights and blinkers and reverse lights and they all work. And this warning light came on shortly after I installed the LEDs, so I think that has to be it.
And when you put the old bulb back in, what happens?
We just took two cars to a band performance and I followed the Camry. Turns out one of the five brake lights is out. Don't know how I missed that last night.
So it wasn't my LEDs!
That's good, were you eyeballing the lights last night or relying on cheap help. :haha:
Thinking back on it, I think I was standing too close to the car when I checked it. I could see that the tail lights all worked by looking up and down the line of lights, and when my wife hit the brakes, I didn't notice the pattern of lights that got brighter wasn't symmetrical because I couldn't take it all in at once. There are 5 brake lights.
Following in the car, I was 100 feet back, and could more easily see. Even so, it was a subtle difference and I don't know if a cop would notice unless he was looking for a reason to pull our car over.
I switched the cars in the driveway so we'll be driving the legal car, and I'll pick up a bulb and install it on Saturday.
if you have 4 of 5 working tail lights, you're probably legal.
Don't give 'em a reason.
It's my motto.
Right, if they hassle you make it for something you can argue in court, not some cut and dried bullshit like an equipment violation. Oh, and have your papers in order and with you.
We're legal now. And my daughter did all the work with me talking her through it. I even showed her how the owners manual explains the process. Nice little bonding.
I bet she remembers that experience forever. Good for you.
Damnit glatt, next they'll be wanting to vote and drive horseless carriages. ;)
Damnit glatt, next they'll be wanting to vote and drive horseless carriages.
Invest in buggy whips and corsets. Retro is the new "in".
How many does it take to replace a light bulb? Any kid knows that. None. If it starts, then nothing is wrong. That's why god invented parents.
Just spotted a self driving car in the wild. As it made a turn when the light changed, the drivers hands were not on the wheel
But that's not proof, I see a lot of people driving without their hands on the wheel. :lol2:
Was that in DC or VA, glatt?
The car pulled up to a red light in Mountain View, CA, and came to a stop. When the light turned green, it turned to the right, and while the steering wheel was turning, I couldn't see the driver's hands on the wheel. I'm pretty sure the car was driving itself.
OK, CA and UT are crawling with them as that's where Google is... um, well, er, "guiding" the DMVs and legislatures in drafting the laws which will become models for the rest of the states.
Another car question.
I've got a cousin for whom I have power of attorney. Just moved him into an assisted living facility. I want to sell his car, but need to get the piece of shit Ford running before that can happen.
2009 Ford Focus
Won't start. Won't turn over. Not even a clicking sound coming from the starter. But the fucking car alarm is going off the entire time. And the flashers flash. And all the lights on the instrument panel are blinking. It's like the car is possessed. I thought initially the button cell battery in the key was dead, so I replaced that with a new one. The doors don't unlock with the key remote, even with a fresh battery. So I unlock with the metal key manually. Get in, and the car starts beeping at me. I try to start the car, and a second or two later the car starts honking non-stop.
The neighbors say that it used to do this for my cousin too.
He has dementia, and had lost his keys. I found paperwork from Ford that they made a new key for him. And I think the car had worked for him after that. But I don't know and can't ask him.
I feel like this is a bad key/alarm/ignition lockout issue, but could be totally wrong.
I'm at the point where I'm thinking of having the car towed to the dealership, but thought I'd solicit advice here first.
Anyone want to buy a fucking Ford?
It could be that the battery has enough charge to operate accessory lights and alarm; but, not the door locking motors or starter. See if the headlights turn on to full brightness and maintain for a bit.
If the gear shift lever isn't fully engaged in Park the car may not start. That circuit connection could also be faulty. You could try starting it while manipulating the shift lever. You could also see if this is a car that will start in Neutral.
With the key in run position (where it would be while driving) can you shift the car out of park? If so, I would guess that the key wasn't the problem.
Also, check the main power connection at the starter solenoid. If the connection, or the solenoid itself is bad this could result in your described condition.
Maybe. Not too up on the modern Fords. Or modern anything.
I was wrong about the year. It's a 2012. And I see he paid for an extended warranty and a service plan, so I'll take a look at the cables and check the shifter too, but won't worry about this too much.
And I see he paid for an extended warranty and a service plan
Oh, well hell, let the mechanic figger it out. Let the glattbrain rest for a minute.:D
Did you come up with anything?
Not yet. I've been too busy.
I'd be looking at the battery and it's connections. the headlight idea is a good place to start, then Pep Boys, Autozone, or one of them, will do a reserve test on it for free. You don't have to take the car, just the battery. You could also try jumping it with your car.
The electrical architecture on newer cars is a nightmare. When they started running signals on the same wire as power it became infinitely more difficult. Every car I've owned I've bought the factory repair manual, but starting with the Chevy manual for my 2006, half the diagnostics say hook up the dealers computer, that costs damn near as much as the car, and walk through these steps. So after this muti-grand computer beeps and whirrs, and bops, it's says, check for a loose gas cap. WTF, couldn't you just tell me that up front?
and you mock my need for an old CJ. :)
Or get the little code reader for about $100. It works on all cars. Cars today with the computer as so much easier to fix as compared to 1960 and 1970 monsters. But that means a $100 tool - that works on all cars including Chevy.
Code readers are wonderful, tells you what system the problem is probably in, although sometimes there's some overlap. However that's not the same a fixing it. OK here's one I've had, P0442 OBD-II Trouble Code. my code reader told me the code p0442 was the reason the check engine light was on, cool. By the way, p0442 is not exclusive to GM.
p0442 - Evaporative Emission Control System Leak Detected (small leak)
The vehicle's PCM (powertrain control module) tests the evaporative emissions (EVAP) system for large and small leaks among other conditions. In the case of this DTC, it indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system.
OK, find the leak and fix it, that should be simple, no electronical wizardry or anything. Where should I look?
A code P0442 most likely means one or more of the following has happened:
•A loose or improperly affixed gas cap
•A non-conforming gas cap (i.e. not factory/original brand)
•A small leak/hole in a fuel vapor hose/tube
•Other small leak in EVAP system
•Faulty vent o-ring seal
•Defective vent valve
•Defective purge valve
•Defective leak detection pump
Hmm, I can check if the gas cap is tight, but won't know if it faulty. Maybe if I light a match by the gas cap. No, bad move.
Leak in the vapor hose/tube. Well the hose goes from two spots on the tank, up to the engine bay vapor canister. A 0.04" hole, huh?
There's a vent valve and purge valve, one's on the top of the gas tank, between the tank and the body and the other is under the hood in one of the hoses. Wonder which is which, my reader only tells me p0442, and the repair manual says hook it up to the dealer's big buck diagnostic computer. Hmm.
In my case it turned out to be the purge valve that's easy to get at, but no way of knowing whether it's bad or not by looking at it.
Well how about a U1255 OBD Trouble Code?
U1255 - GM
Type Network - Manufacturer Controlled DTC - Manufacturer Controlled
Description Class 2 Communications Malfunction
Cause ECM DTC B with Freeze Frame and Failure Records stored or TOM DTC TCM flashes Sport Mode Indicator, TCM sends a MIL request to the ECM, the ECM illuminates the MIL, TCS is disabled and the TC Indicator is illuminated
Got it? Got it. Good.
Cars today with the computer as so much easier to fix as compared to 1960 and 1970 monsters.
That's the craziest thing I've read this year.
lol. yeah, I was gonna just let that one go.
Edit: I think it's fair to say that cars are more reliable now and don't need fixing as much as cars back then did. But when they do need fixing, it's exponentially more complicated.
I think it's fair to say that cars are more reliable now and don't need fixing as much as cars back then did. But when they do need fixing, it's exponentially more complicated.
Actually it is not. Ever try to fix a Pinto? It took multiple part replacements before we finally traced the failure to a cam shaft and then to many burned out diaphragms in the carburetor. Nothing would tell you what was wrong. The solution was to just start replacing parts - ie always start with a tune up.
I have traced failures immediately to a defective part by simply viewing a computer code. For example, fuel injectors were on too long. That was immediately traced to a fuel pump that worked just fine - but had insufficient fuel pressure.
View this
My check engine light is on discussion. The computer code said exactly what was wrong. Only problem was a mechanic who could not understand how to see a defect clearly identified by a computer code.
Many problems are not complete failures. Most problems are changes (ie worn camshaft, sticky Idle Air Control valve, etc) that cannot be found without a computer. In one case, a partially obstructed nozzle cause an EGR valve to respond slowly. Computer quickly identified that defect that would only get worse with age.
In days before computers, one car would sometimes knock. It was taken back to a dealer multiple times who could find nothing wrong. It took me quite some times to find her problem. Centrifugal advance and vacuum retard plates inside a distributor were sticking. This could only be observed when the car accelerated and since plates did not always stick. Had a computer existed, this problem would have been identified immediately. Distributor removed, cleaned, and all knocking ended. Sometimes it takes courage to disassemble something as complicated as a distributor especially when it is not your own. It took quite some time of driving, playing games of what if, and eventually removing and disassembling that distributor to find the defect. Computer would have identified it immediately.
Computers have clearly made defects now so easy to identify - in some cases before that defect causes a roadside breakdown. Computers have clearly made auto repair easier as now seen by more reliable cars and even by a reduced number of roadside breakdowns.
Are you an auto mechanic, tw? Or were you in the past?
I was a heavy equipment mechanic, and I could have diagnosed that Pinto in about 10 minutes.
Having gotten 270,000 miles out of my 2009 Chevy Impala (and she was still in good shape when I traded her), I found that the secret to a long life with your car is regular maintenance and a good mechanic...and good tires.
... I found that the secret to a long life with your car is regular maintenance and a good mechanic...and good tires.
Brakes don't matter?
Included in regular maintenance...but I emphasized tires because you really get what you pay for on them. Don't buy cheap ass tires.
A 78 Malibu don't start? It's fire, fuel, or air. And there are only a couple places where either can cause problems.
Popdigr's 01 Grand Cherokee? The diagnostics says it has a bad O2 sensor. There are four. Which one is bad is not specified. If his GC doesn't start, it can be, literally, one (or a dozen) of 75 different things creating the problem.
I think it's fair to say that cars are more reliable now and don't need fixing as much as cars back then did. But when they do need fixing, it's exponentially more complicated.
Agreed, 100%.
I don't even work on my own cars.
I can turn nuts and bolts and replace stuff...but, I'm no diagnostician.
This is the last car I 'worked on' with any regularity:
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