CarComplaints.com Notes: The Cobalt was introduced to replace two of Chevy’s smaller cars, the Cavalier and Prizm. But the compact’s fresh start that Chevy was hoping for was riddled with issues, most notably widespread power steering failure.
I've had this same problem that many others have reported on carcomplaints.com as well as CobaltSS.net and Reddit.com.
When the engine is at idle, it will frequently "shudder" and the RPM will dip down to a low level, approximately ~500. This causes the engine to nearly stall, but it immediately jumps back to ~750 RPM. It may continue to bounce between a low RPM and the normal idle RPM for a while. When it drops to the low RPM, the lights on the car will dim as if it is an electrical issue.
While the car is cruising (either in gear or neutral), the RPMs will bounce like crazy between 800 and 1,500.
I have read that this could be due to a gunked up Mass Airflow Sensor, but I haven't had the problem diagnosed or fixed yet.
The consistent up and down of the elms. Shutting off due to the idle dropping out f no where. This sucks. I have had my car check several times and nothing can be found, even if my engine light is on.. It's enough.
im not sure, but after the steering problem got fixed, and now my new battery but i still have the dimming lights when I slow down or stop, i dont know what the hell to do. I only have a year left to pay on the car and i cant afford a new one, so now what. I am pissed beyond pissed.
Chevy dealer in town refused to honor carmax warranty to replace engine but charged me 1500.00 to diag problem to repair and pull head &one piston don't recommend the GM dealer in Henderson N.C.
After the heater box splitting and flooding the carpet, blower motor problems, faulty wheels,chrome falling off the trim,key lock sticking on the steering column, headlights blowing, the idle began sticking. I found on a racing post others having the same problem and CHEVY dealers unable to find a fix, someone noted carbon build up on the throttle blades. These cars don't have a regular throttle cable to force them open. Asmall electric motor opens the blades. If they stick, the idle goes up nad down, nearly dying. If it sticks when you try passing traffic- HOLD ON FOR THIS- THE CAR KNOWINGLY KILLS YOUR POWER!!!! YA, IT FLASHES A MESSAGE. "ENGINE POWER REDUCED". i WENT STRAIGHT TO THE DEALER. THEIR ANSWER, TURN THE CAR ON AND OFF A FEW TIMES IT WILL RESET. I'M TRYING TO MERGE WITH TRAFFIC DOING65 AND THE CAR TAKES AWAY POWER!!! THIS HAS TO BE ILLEGAL!? The EXPENSIVE fix that those 75$ a hour GM mechanics cant find, a 5 dollar can of carb cleaner, a screw driver adn about 5 minutes. Haven't had the problem in over 3 months!!! Screw GM like they screwed me. Let em go belly up!!!!! I ll buy another Nissan- 175,000 miles trouble free!!!!
A D V E R T I S E M E N T S
I've had this same problem that many others have reported on carcomplaints.com as well as CobaltSS.net and Reddit.com.
When the engine is at idle, it will frequently "shudder" and the RPM will dip down to a low level, approximately ~500. This causes the engine to nearly stall, but it immediately jumps back to ~750 RPM. It may continue to bounce between a low RPM and the normal idle RPM for a while. When it drops to the low RPM, the lights on the car will dim as if it is an electrical issue.
While the car is cruising (either in gear or neutral), the RPMs will bounce like crazy between 800 and 1,500.
I have read that this could be due to a gunked up Mass Airflow Sensor, but I haven't had the problem diagnosed or fixed yet.
- Timothy C., Charlotte, NC, US