Just traded in our 2006 H2 for a used red 2007 H2 SE with 11K miles. Real beauty. But does not sound nice. The 2006 engine was very smooth idling, and had strong pull through all rpms.

But the 2007 engine has a noticeably louder and rougher idle. A bit of a growl. Slight vibration clinking noise from under the hood that was not there on the '06. Sounds a bit like an aftermarket exhaust (but it is stock of course). The growl grows when accelerating from a stop with increased foot pedal travel and rpms, until the vehicle reaches about 30mph. Can't see anything.
The 2006 was noticeably quieter at idle, and smoother at all speeds. No growl.

So the first thing I did was change the new oil that the Hummer dealer 2-litre overfilled during a change to synthetic when I finally got the freshly changed over-tightened and siezed oil filter off. Just after they delivered the 2007 H2 SUV to me. Hopefully this screwup on their part did not damage the engine, as it was only driven this way for 50 miles before I got it home.
I am using the same oil, and the vehicles have about the same miles on them. Threw in 2 bottles of injector cleaner into the tank. No difference.

Has anyone else noticed this difference between the 2006 and 2007 models? Is this growl normal, or does the 2007 have something wrong with it? Seems to run fine otherwise. Just more noisy.

Did anything change from 06 to 07 in the engine, tranny, or exhaust that could be causing this difference?

Help!! Anyone who owns or have owned both an 06 and 07?

Help!! The truck has an appointment with the dealer on Monday for this growl, but I would like to avoid taking it in for exploratory surgery if it is not needed.

 

I haven't heard an '06 OR '07, but NOTHING changed in the engine, tranny, or exhaust since the H2 debuted in '03???

Kinda WeIrD????

I'm assuming it's still under warranty(unless the mileage is crazy), so I'd raise my concerns and let the dealer figure it out!!

 

the engine got some more power from 03 but i still think its the same engine, he said its only 11k miles so it shoud be under warranty, something isnt right tho

 

Someone just told me that the 07 has 3.5" exhaust versus 3" on previous years. Is this true? Does anyone have an 06 who could wrap a measuring tape around the exhaust pipe (not tip, since tips can vary in size) and measure the circumference to confirm this difference?I can then calculate the diameter from the circumference (d=c/3.14).

I do not have the 06 anymore, so I can not do this myself.

Help please!

 

I have the same 07 special edition. The motor does not seem to have any growl. From the tailpipe end it sounds like a chevy though. Very quiet and smooth on take off. I got a loner when mine was serviced and it did grown a little. But it had 55000 hard loner miles on it. I would have them check it out. Take it to a good hummer dealer. My dealer in connecticut has hummer specific techs. they only work on hummers and are great. I am not sure if all dealers are this way though.
As for the truck way to go red rules!!!!!!enjoy

 

I posted a reply to your 3.5" exhaust inquiry on the Elcova forum with a link providing confirmation of the size bro.

 

Hi Tomp,

Got it. Thanks for the info!

Well, the H2 SE is in the shop at the dealer to check out the engine growl, and they can tell me what the heck is going on. Is it the new exhaust, or is there something wrong?

Just noticed that if you touch the right front tire, you feel more vibration than off the left front. The engine at idle is causing this vibration. Again, not sure if this is exhaustrelated, or if there is something wrong with the engine. We should hopefully have an answer in a few days.

 

Good Luck and Keep Us Posted!!!!