Thank you for the help! It is much appreciated.
I wont be able to spend any time on it until next weekend though... so I got some time to research more.

 

Its been diagnosed as a burnt valve. car has under 90,000 miles and well maintained.... I think I am done with GM vehicles. Too bad, I've owned them my entire life (been driving 34 years), but this HHR that my wife drives has had way to many problems.

 

Car was in the shop for over a month. The head was sent out to a machine shop for new valves and milled. Reassembled and when started up it ran fine for a min or two then stalled. Mechanic said the timing jumped. Fixed the timing, started it up again... same thing. Fixed it again, started it, timing belt jumped and ruined head and motor. The shop calls me and gives me the news that the $1500 bill to fix, will now be $2500 to install a used motor. All because the head was milled which made the timing belt/chain loose.
The car is now way out of alignment (4 wheel) which was just done last fall. Should an alignment have been done when the replaced the engine? Does it come out by dropping the cradle from the car? Or is it removed from above?

FYI - The shop I used is from my work place, but a different dept. I work in the collision dept separate from the service dept and thought I was in good hands...

 

No timing belt on this engines.

If it jumped time(which I doubt) then it sounds like a R&R mistake.

Sounds more like it was reassemblied out of time. Probably an unfortunate mistake that trashed the engine once it was started and run.

 

They Should have tried to sell you a new chain kit including guides, if they did and you said no,, OOPSIE.

The engine can come out either way I understand, haven't done it myself.

The only time an alignment is required is if the tie rod ends (toe settings) have been messed with. I am not sure why that would have happened in any event, maybe they pulled the motor and trans as a unit, which would require pulling the axles? I don't know enough about that part.

 

I agree - milling the head would not make enough of a difference to affect the timing chain.

 

Not really sure why it would have needed a cut(mill) on the head anyway. Back in my mechanics days, the only heads that ever needed a cut it seemed, were ones that had run hot and warped a little.
If you do cut one down, it's only a few thousanths anyway. Not enough that the timing chain tensioner can't make up for. If a few thousanths didn't clear it up, head replacement was needed.
I also remember you could get oversize or thicker head gaskets to make up the difference. Not sure if they're available for these engines.

Don't recall the OP having any overheating issues with the original problem.

Also, I think someone has posted before that it is advised NOT to mill the heads on these engines. Replace the head if needed I seem to recall reading.

 

They are aluminum and Chevymgr used to say non-machinable because of not enough meat.