I have been having an issue that the dealership can not find to fix. I have a 2007 2.4 that is having an issue with the rpm jumping at a light when I come to a stop. The car will come to a complete stop sit for a while and than the rpm will jump to 1500 -1800 rpm for some time and then go back down past 1000 rpms. Has anyone else had this problem.

 

Sounds like vacuum... very strange. Someone else needs to chime in and help this person out!

 

I'd suspect the throttle body or the idle air control, I'd also take it someplace else since those folks aren't doing the job. A first stop you might think about is an Autozone or the equivalent where they can pull the code/codes and you can give that info to another dealership. And before I forget....Welcome and Greetings!

 

I have no codes. I have had this problem since the car had 12K on it. The car seems to want to take off while sitting at the stop light.

 

I'm still hedging with the throttle body or the throttle pedal assembly, but this issue may be rooted in the ECM itself. Have you contacted the GM zone rep about this?