engine or trany problem
 

have a 07 HHR,72k miles, auto trans, mostly no problems, intermittently now when stopped at light with foot on brake, car feels like it is trying to move forward , like your were engaging a clutch (surging)and pushing it back in and then it does it several times and it stops. Anybody else experiencing that condition and any suggestions. I guess if it's a trany problem it would be covered.

Beachbum1

I have the same problem with my 06, 75,000 miles. I believe that this is a electronics problem but i can't seem to solve it. Replacing, the spark plugs, making sure all fuses were tight, didn't help the problem. I narrowed to either a faulty electronic throttle unit or maybe fuel injector issues. I have never had a code thrown on my car which makes it harder to diagnose. I really think it is the electronic throttle as other people here have had this issue and had the throttle replaced and it seemed to fix it. The throttle assembly is all one piece and includes the sensor, you can find it online for around $130, the price is all that is keeping me from fixing it as this issue is really an annoyance more than a problem right now for me.

Is there anyway to test with a DVOM or using a generic scan tool? You can actuate the throttle and watch the DVOM or scan tool and look for dead spots in the electronic throttle. Just a thought have done this on a few cars but not an HHR.