I have a 2004 Cavalier with the 2.2 ecotec engine. One day it started stalling everytime you stopped. Now it has just been a rough idle bouncing between 500 and 1000 rpm's. Runs good otherwise, driving up the road it does not exhibit any problems. Change IAC after cleaning didn't work, also tried map sensor, ICM, and coils. Kinda irrelevant at this point.
I took it to a shop I trust and they hooked up their snap on scan tool and he said everything checks out except it is running rich. The only code I get is PO172. He said that he thinks it is a timing issue. Also my gas mileage has been cut to about half of what it is normally.
Could I have a timing chain problem at 128,000 miles ?
I know I see the rough idle question alot but never really find any answers, so if you have a clue let me know, I hate to tear into the timing chain and find out it was something else. It looks awful tight to me in the engine bay, is it that hard to change the timing chain, I'd rather do it myself but if it is a better idea to have a shop do it let me know. If you take your time can you squeeze into the space and get to everything you need to.
Any advice comments would be appreciated. Thank you everyone.
How many miles are on it? And if it runs pretty good going down the road, I wouldn't really say timing chain, They get loose enough to lose a little power but nothing like that, unless the tensioner breaks and it jumps time, You would know when that happens, lol. After everything you listed, I would probably say O2 sensor may be in question, vacuum leak, or maybe the even the cat. I would check those next before even coming close to the timing chain.
well after some looking around,I would look at changing your MAP Sensor,or start with the front 02 sensor.
And if i remember do not use a bosch 02,I think ppl have had issues with them..
Best of luck,let us know.
Tried map sensor already, scan tool said oxygen sensor was good. Now what ?
When my timing chain stretched i stopped at a light and the car started to vibrate more then usual. Just pop off the valve cover and take a look and see if there excessive play between the cam sprockets.
Just because the scan tool says the O2 sensor is good doesn't necessarily mean it is. It just means it's sending a signal. So it could possibly be the wrong signal. I would throw EGR into the mix but if i'm not mistaken, ecos don't have EGR. Wow, and didn't notice you had already put the mileage in your post, lol, my bad. Still kinda leaning towards what I suggested before. But with the mileage, it would be a good time to take a look at the timing chain anyway, they are good to change about every 100,000 miles. AIT sensor maybe, highly doubt it though.
fuel filter, spark plug boots, ICM . maybe just time for a basic tune up!
Already tried map sensor ICM, coil pack.
try air filter and fuel filter both cheap. just replace them and see if it help the problem at all. i know when my car exibited the same problems you are talking about, i did a full tune up. oil, air and fuel filters, spark plugs and boots, and the issue went away.
I just rececently had a similar issue with the fuel pump it was giving me a rough idle loss of power and also hesitated from a stop after it was goin it would pick up fine, also check the wiring that goes directly under the car near the fuel pump I had a wire that was stripped down to the bare wire and never knew it which it had also then fried my bcm....
Guess it is time to take the valve cover off and check compression and timing chain unless someone else has any ideas.
Parts changed
Map sensor
Ignition Control Module
Coil Pack
Fuel Pressure Regulator
Idle Air Control Valve
Spark plugs
Took off throttle body and cleaned the whole thing
Unplugged Oxygen sensor, no change
No Vacuum leaks
Battery is good
Alternator is good
Still surging idle, stalling. Only code is PO172. Running Rich verified by all 4 spark plugs being sooty.
Sounds kind of like what mine is doing/did.. I say did because it won't even start..
I think i'm gonna check what all these guys have suggested, starting with timing chain etc..
I too had my CEL on and got the rich message.
03 Cavalier.. roughly 115K on ticker
/thread jack
