My 05 H2 SUT 46K miles-- If you accellerate away from a light when you let up on the pedal i GET A CHIRP OR A SQUEAK....
*** does not do it in the driveway in park reving engine****

pretty loud around city buildings not so bad in the suburbs... had it at dealer for trans flush and fill, and a few minor issues under my GMPP, took tech out to show him the noise, they said couldn't really find it and lubed body bushings.... the noise is still there and seems louder in colder weather....

Any body else have this squeak/Chirp??? kinda sux to have a sweet ride and it sounds like a hoopty....

Any help would be great

 

This probably isn't the problem isn't the culprit, but mine was making a strange squeak occasionly butt consistently when driving. It was the surface panel that's between the hood and windshield being loose. I pressed the windshield squirter down the other day to because it looked loose and the same sound I'd been hearing for a couple days was made. Like I said, probably not but spent a couple days to accedently find my squeak and thought I'd mention. Good luck.

 

Try jumping on your front bumper- get the front end moving up and down. Put a receiver in the hitch on the rear give you some extra leverage, try it back there also. If its something in the suspension when your letting off the throttle, it will be in the front end downward movement, rear end upward movement.

You sure its not a belt or pulley noise?

 

I had a squeek during accelleration and ended up being the wheel bearings in the front. I had no grinding sound you normally get from wheel bearings going bad. I would jack up the Hummer and shake the wheel and see if you have the similar issue.