'06 Sebring

I have an '06 Sebring convertible, 2.7l, V-6, 58,000 miles. When stopped with A/C on, car tends to surge. When I put in neutral, surging stops. Also, I sometimes get a “thump” (with both sound and feel) like I’ve been rear-ended, but have not. Dealer did tranny serivce and replaced all plugs and 2 coils which they said were “arcing”. Did not fix problem. Any ideas? What would be wrong with A/C so as to cause this?

Is the thump while driving or while stopped?

The problem probably has nothing to do with the AC, mechanical side anyway. I think this is going to be an IAC (idle air control) motor problem.

Might also be an O2 sensor going bad. Saw this same symptom occur with girlfriend’s GM car when the O2 sensor went out. Argo at Autozone diagnosed the “downstream O2 sensor” as bad. We put in new O2 sensor and problem went away immediately. Get Autozone to do a diagnostic on the car (for free!!) and they’ll pinpoint the problem for you. An O2 sensor is @ $80. at Autozone. We did it ourselves in about 1 hour, with a tool borrowed for free from Autozone, and it was as easy to change out as Argo said it would be.

Thanks. I’ll check it out.

Talked to dealer. Said no problems with IAC or O2 sensors. They found another bad coil at no charge. I will drive for a while and let them know.

Not guaranteeing, but I hope this is it, because that would be a real cheap fix. At least it won’t cost you anything for the diagnosis. Best wishes.