Vibration at 1500 RPM

[finall]

Ok, I have now crawled under the vehicle.

YES!!!! The crossover exhaust pipe (going from right side to left side collector) is totally pancaked against the UCP (undercarriage protector). GM tried to pancake the exhaust pipe so it would clear, but failed. I had to drop the back of the UCP bolts by 1/2" before the exhaust cleared.

The rub point has filed down the UCP at the contact point and exhaust pipe also. If this was left alone, it would have eventually made a hole in the stock exhaust and UCP!

Lots of loose metal rust filings in the area, so it was easy to spot. I could not even slip 1 piece of paper between the two pieces of metal. Could this be the problem? Either way its off to the dealer to fix the exhaust.

I easily removed the UCP (3 bolts) by loosening the front skid plate (5 bolts), and will go for a 50 mile test drive later today. Let's just hope that this is the problem. Either way, it is off the the dealer for warranty exhaust repair.

AdamInCo: you may be the Hummer God after all......More to follow.

[finall]

Ok, I officially declare "Adam in CO" a Hummer Guru God, and I bow to him.

The problem is solved!!!!! I love my Hummer again~!

The big local Hummer Dealer could not figure this out.

I was starting to hate it because it was vibrating me to death.

It was in fact the droning from the exhaust, that transfered to the UCP, and then to the rest of the vehicle. Took the UCP off. Just came back from a 60 mile run, and NO MORE vibrating growl NOISE!

I bet every 2007 H2 has this problem, since my exhaust was 1/2" too low in that spot, and that is a lot. I bet they do not have that much tolerance during production.

So off to the dealer to get their muffler shop to repair this HUGE defect. I would be surprised if there was not a TSB on it.

In fact, does anyone know about a TSB on this that I could take to the dealer?

The other brand new 07 I took for a spin odd the Dealer's lot to compare definitely has the same problem. I am glad I did not give up and assume that there was no problem, and that they all sounded like that.

Thanks to great help from great guys like "Adam in CO", on this forum, weird problems get diagnoses and fixed. Thank God for this forum, whithout which I would still be in the dark about the problem, or just have to live with it.

I love my Hummer again~!

[HUMMERcustoms.com/TAZ]

Great glad you got it corrected.

I was going towards exhaust only because I had it happen on a car with me before only from a different cause. But, with all the protection H2's have I was reluctant to go straight to that idea. Adam hit the nail on the head. He is a very knowledgable and good guy. I had never heard of mentioned problem on H2. Good to learn something constantly so I can pass it on to Dragon and the shop.

Great job Adam. Thanks for teaching me something knew.

TAZ

[Adam in CO]

Makin' me blush.