Hi, my 08 HHR SS keeps stalling after cold start. I'll start it with no issue after seating the whole night. Then it will drive fine. But as soon as I stop at the next red light it will just stall. I'll then put it in park and start it and it will run fine the whole day. This happens at the same exact location and around the same time. Temperature is cold. The heater would be running. I just acquired it about a week ago. Runs well otherwise. I have been using premium gas and I don't know about the previous owner. The only thing I have done so far is change oil and nothing else on the engine. I used Mobil 1 5W30 Extended. Any help will be appreciated. Thanks.

 

My guess is fuel pump.

 

Same here , the in tank pump. You say you only changed the oil, I must ask about the oil filter , did you change that? How about the air filter? How many miles on the odometer? Perhaps it’s due for new spark plugs AC Delco iridium plugs work the best, for that matter maybe it’s got the wrong plugs in it?
Also, is the check engine light on? If it is, have the codes read and post them here, please

 

Interesting. Strange that it only happens once and after cold start. Runs fine the whole day and night. Thanks.

 

Hi and thanks for responding. Yes I did change the oil filter with a Mobil 1 brand. No CEL light at this time. Nothing else has been done on the engine. Yes it probably needs tune up: air filter, spark plugs, ignition coils...the mileage is 155K. Maybe clean the throttle body and MAF sensor? I really love the car. Runs smooth through out the day.

 

Plugs yes, clean the MAF and throttle body and go from there.

 

I have the same year and model. Last month the car started becoming hard to start. No codes relating to fuel showed up. I tested spark, compression, fuel pressure,electrical circuits because my engine eventually would not start. As mentioned no codes. After much consideration, I replaced the High pressure fuel pump. Problem solved.
Unrelated, but after checking the timing chain, it was loose and the plastic guide was broken. All repaired and running like a Champ! I was surprised that a timing chain was bad at 140000kms.

 

Didn't some of the SS automatics need to get a vaccum pump installed?

 

I definitely will. Will post updates. Thanks a lot.

 

Yes. But that was for a hard brake pedal at cold start up. Don't think it had anything to do with stalling.