We took the Hummer in for oil change and because the engine light was on. Now they say a cylinder head is leaking. We have brought the Hummer in several times with the engine light on and they have never found a problem.
Now (after the warranty is expired) they find that the cylinder head is leaking and have a $3,200 repair recommended. I have now seen many posts similar to mine, is this a recurring problem with the 5-cylinder engine on Hummers?
Call gm as they may have a campaign on it and will either split the cost or take care of it completely. Especially since you have had it to the dealer several times for an engine code that noting supposedly coldn't be found. Of course you can always go to a service center other than a dealer for a cheaper price. They do just as good of work.