'07 H3 49K miles Strange sound at accel

I have a 2007 H3 with 49k miles on it...I have had it a little over a year and I have been noticing a strange sound when I accel.  I have taken to the dealer twice and they are telling me that it is a normal sound that Hummers make.  The best way to describe the sound is that it sounds like I have a playing card stuck in my spokes...remember that from when we were kids...Does anyone have any thoughts on this...it is driving me nuts!!  By the way...my H3 is in the shop to have the exhaust manifold gasket replaced...is this normal??

Sounds like the heat shield on the manifold or cat is loose.............just a guess, and easy to check

When test driving the H3 we just purchased we found a rattle and it turned out to be a heat shield that was loose.

Ok here is the update!  It turns out that the exhaust manifold was cracked...not just a bad gasket...so the dealer replaced it and when I FINALLY got it back after a week, I noticed I had fluid all over the back of the H3!!  Took it back to them the next day and the transmisson filler neck had been reinstalled correctly...UGH!  Long story short...It is running great and all of the "strange" sounds are gone...I hope that nothing else goes wrong!!  I love my H3 and I plan on having it for a long while!! 
 
GO STEELERS!!

Glad it worked out and thanks for coming back and letting us know what the issue was...

Ohhh I hate to bring up an old topic... but I also am just starting to have this problem
06 H3 @ 13k Miles

It sounds like something in the engine is vibrating at about 1900 revs

The playing card in the spokes is what worries me
Hate to bring up an old topic