I've had my new Cobalt SC for a couple of weeks now and I'm thrilled with the car so far.
Good job GM.

BUT,


I've noticed that sometimes the idle goes erratic especially if I've almost stalled the car and even though I've pushed the clutch in, the idle may go erraticaly from 500 rpms to 1200 rpms up and down 4 or 5 times before it settles down.

Anybody experienced this????

This is very intermittent and kinda hard to reproduce but when it does happen, it's a pain in the butt.

Now, the car is an 06 Cobalt SC with 800 miles on it.

Thanks for your help.

 

take it to ur dealer, the computer just has to be reflashed

 

Took mine to the dealer twice and they said that it had the correct flash and it still did it. Mine got real bad a couple of weeks after I got it and then did it less and less and now it hasnt done it in 3 weeks. I bought mine on january 3rd.

 

From what you've said it sounds normal. Sounds as if the computer is trying to compensate for the near-stall and it will take a few seconds to do that. If it were doing this while engaging the clutch while rolling to a stop, then there may be a sensor or computer glitch. But if you are almost stalling out it sounds like all is ok. What did GM say? Call the service dept. and ask yet?

 

I have the same problem and it does it even if i haven't "nearly stalled" it. It a problem that I think quite a few people on here have. If you rev it to about 2k it will quit.

 

Yeah, mine does it sometimes also. It's almost like a small amount of oscillation gets into the throttle body control signal. A small blip of the throttle will make it stop. I only catch mine doing it a couple times per month.

 

I had the same issue with the idle dropping...I took it to the dealer and they said "well your car has the new software in it so you dont need a reflash" crap

 

yea my car does the same thing so im guessing its normal.

 

I tried getting them to do a re-flash but its almost like they refuse to do it.... I guess maybe ill keep bitching

 

My surge at idle went away by itself after the car got to about 4 or 5k miles. Hasnt happened ever since.

 

Hmm isn't there a re calibration out for rough idle?

http://calid.gm.com

 

this happend to me and the tech said there was no reflash for the car

 

Same with mine, I just gas it a bit, and it goes away.

 

Reflash is for '05 only (and still doesn't fix the problem, btw). '06 is supposed to already have the proper version installed.

 

Same for mine, well mine quit after about 2k-3k miles. Still does it sometimes if I almost stall.

 

I just noticed it last night for the first time but the idle steadied & all was good. I have 800 miles on my bad ride.

Mods to come.
exterior first though---

 

Ya thats an easy fix, i have that happen when i downshift and approaching a light and go out of second sometimes and the needle kinda bounces. Just tapp the gas a little and that will settle the mottor down. My guess to this is that there might be some resdiual boost that has to work its way out. Although this is only a thoery for this little glitch but my solutions has worked every time.

 

Wow, I didn't realise this was as common as it is.

GM will need to fix this. I know that it doesn't really make the car undriveable but when it happens will make it very annoying and potentialy hazardous at an intersection.

We shouldn't have to launch the car at 2000 rpms to make sure it doesn't happen or slip the clutch more than we have to. The clutch won't last long when doing that.

I wonder if it's a problem exclusively with the 2.0SCs cause my sister's 2.2 cobalt and the NA 2.4SS I've driven seem to behave totally normal.

I know that some fluctuation is normal but not to the point that it will go up and down like that from 500 rpms to 1200 up to 5 TIMES AFTER THE DAMN CLUTCH IS ALL THE WAY IN.

Anybody noticed if second gear sometimes feels like there is lag before getting boost in the lower rpms that only happens intermittently as well?

I swear sometimes is feels like it has turbo lag after shifting to 2nd when most of the time this doesn't seem to happen.

Thanks guys. Let's keep trying to figure this out.

 

This is normal. you'll get this even after you rev your engine. Its because we have throttle by wire.

 

Yup, mine does this too. Absouletly drives me crazy. I don't understand how they didnt catch something like this before production.

 

The LSJ has had this issue for quite some time now. Theories range from the Boost Bypass Valve opening at low RPM to help us with fuel economy to an ECU that was tuned to keep things in check. My LSJ sits inside an 04 Red Line. Sadly to say you just have to get used to it. I've gone to the dealer on several occassions to complain about this to no avail. On the Red Line forums its referred to as the "bucking bronco".

 

Hmm ya i know what your talking about when it comes to second gear when you shift into it and its under 3k on the tach. Just remember that when deal with forced induction when you shift there is period wear boost has to build that is all but i like it whne you feel the boost buil and the car feells like it tied to something and just being pulled full force i love this car

 

I've had my SS/SC for almost a year and talked to many pro's and none pros about it and it's normal unless your car idles like this all the time or actually stalls. It happens to me every once in a while.

 

EVERYONE IN THIS THREAD...

see my post in this tread...there is a problem...GM is aware, make sure to go to your dealers so you are documented as having this problem. the more they see it popping up the quicker we can probably get a fix

https://www.cobaltss.net/forums/show...t=14551&page=2