My 07 H3 has been in the shop for a month while the GM dealership plays guessing games on it. This is the list of the things replaced so far that I know of because they have been shady about it.
Left Front Axle
Front Pinion Seal
Manifold
Transfer Case Internals and actual case
Trasmission Pan Seal
U Joints
Cylinder head
Cam shaft timer or something like that
Radiator
differential actuator or something
and some other miner seals and stuff i cant recall
Now they called me today and said they ordered a part for Monday and didnt say what. I have a someone I know who works as a salesman who keeps an eye on it for me who said the the mechanic told him that whoever owns it should trade it in as soon as possible because the cant find whats wrong with it. I have no idea what I should do about this. but they keep giving me a loaner car I cant put any miles on hardly, cant take my dog in, and is a Chevy Cruze. Wtf

 

it has 80000 miles and they just got the head done today and once the mechanic drove it the errors came back up saying reduced power and traction failure. Before I gave it to them It was just the manifold and once it go warm after about 15 miles it would start misfiring and then just turn off and not start for about 10 minutes.

 

Holy crap. Keep us posted.

 

Sounds like a sensor or the computer. That's old school diagnosing. Good luck don't let this discourage you

 

one good way of looking at it is by the time the mechanic finds it you'll practically have a new Hummer : )

 

Wow

 

It seems that there are very few real mechanics left these days. We seem to be stuck with "parts changers".

 

I get my hummer back today I'll update tonight with the info

 

They replaced the cam shaft actuator and found a blockage in the solenoid. Dam thing died on me twice so far today but it did it this time when I pulled into the driveway it died before I put in park. Atleast its not misfiring anymore.

 

Damn and I thought my H3 was a pile. Good luck man.