What is the cause of a rough idle when accelerating after recent car repairs?

Asked by May 24, 2017 at 12:26 PM about the 2006 Chevrolet Cobalt LT Sedan FWD

Question type: Maintenance & Repair

Last week I had to have a thermostat and cracked coolant tank replaced on
my 06 Cobalt. A few days later and coolant system works fine, but there's a
new "hitch" in my idle when accelerating with a touch of what feels like drag.
I'm unsure if this is a serious issue worth taking to the shop right away or if
it's just a nuisance.  A few months ago I encountered the infamous 'Balt stall-
out that was fixed with a reflash, but this feels different and isn't stalling.

Anyone encounter this problem? What should I do?  I already missed a ton
of work due to last week's thermostat problem and would like to drive it until
the end of the workweek but I'm not sure if that's a bad idea.

6 Answers


First thing you need to have is the computer scanned,it will hold a code and more than likely tell you the issue,with out code you are just guessing Take it over to AutoZone during lunch and they will scan for free and give you the error codes

1 of 1 people found this helpful.

How many miles on the car? Have you ever had your throttle housing cleaned? Take off the plastic component that covers the air filter. Check if the air filter is dirty? if so, that is half ur problem. Then get some carb cleaner and clean up the throttle housing and Mass Air Flow (MAF) Sensor... Finally, place a bottle of Techron in your gas tank before u fill up next time. All these steps should help with your "hitch"

1 of 1 people found this helpful.

Lastly, try this video from you tube. 2006-08 Chevy Cobalt TCM FIX! Easy! BCM Problem, Connection issue This is a common issue for your car https://www.youtube.com/watch?v=EzQZbGp14ro

Thanks for the advice! The car has 128,000ish miles on it. No error codes were found by AutoZone tests. Not sure if this is good news or bad. Air filters were dirty and I changed them, Techron was added this morning on an almost-empty gas tank. The misfire improved a little, but got slightly heavier the next day. There is still a misfire but it sounds a little better/different. I suspect a spark plug issue issue, but I'm sure the filters were not helping. I'm taking it to a trusted mechanic near me to get things cleaned/checked.


Glad you checked, and weird that there were no codes. After u put Techron in....u did fill the tank? That is what is needed normally....and it would clean ur pistons and mechanical parts over a few days. Misfiring....or after u turn vehicle off.....it continues to have a short continuance...that is due to bad gas. Try a tank of premium...or at least half a tank, if possible. and tell me the effect


When was last time u tuned up car? Take one spark plug out and see if it is gummed up and blackish?? Also replace ur fuel filter....if u had a lot of gasoline w alcohol....they tend to tear up the fuel filters.....they are paper inside. Especially if u use the 85 gas....it is 85% alcohol That would definitely put a hitch in ur acceleration

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