Squeal and flapping sound

[H2inMD]

Its seems to get worse if you push the engine, we were reving it up to try to hear the noise and it got worse.

next step , when its cold, I am going to take the belt off and see if it still makes the squeal. This will start to isolate the problem.

any other ideas?

[H2 Bill]

On the "main drive belt" there is a tensioner pulley and an idler pulley. I had to change both to make the noise go away.

[H2inMD]

we've diagnosed it better, so I started a new post. Whistle from Intake manifold?

[H2inMD]

Unbelievable. 3 nuts/bolts broke off on the exhaust manifold passenger side.

You got your tick tick sound, then as you accelerate, it whistles(cat screech) with more exhaust flow, then if you get on it, the manifold itself is lifting on and off the head hence the flapping/banging sound.

Saw the tech bulletin on the fasteners, why didn't the original dealer ever contact me, why not GM. The tech bulletin says to replace if brought in for manifold service. Guess if it fails you bring it in. Would have been nice to change them before the failure.

[pdsq99f4]

Originally Posted by H2inMD

Saw the tech bulletin on the fasteners, why didn't the original dealer ever contact me, why not GM. The tech bulletin says to replace if brought in for manifold service. Guess if it fails you bring it in. Would have been nice to change them before the failure.

If you were GM would you send letters to everyone who owns a Hummer saying "you may have some exhaust manifold bolts break, so watch out"? Do you know how much that would cost? It would definitely bring me more business though as a technician. I'm sure if you got your vehicle serviced by someone who KNOWS your H2 they would have seen the broken bolts a long time ago. I know I would have.

[H2inMD]

Originally Posted by pdsq99f4

If you were GM would you send letters to everyone who owns a Hummer saying "you may have some exhaust manifold bolts break, so watch out"? Do you know how much that would cost? It would definitely bring me more business though as a technician. I'm sure if you got your vehicle serviced by someone who KNOWS your H2 they would have seen the broken bolts a long time ago. I know I would have.

Well maybe thats why GM is now Gobvarmit Motors and Hummer is now a Chineese Entree' best served with 93 octane

Dont get my wrong I love my H2, but maybe they should tell you things, i dont know. Actually, i have never kept a truck or car past the warranty before, so @ 95K this is new territory for me.

As for service,what service. I get the oil and fluids changed. i did the spark plugs. What else do you really need serviced? And its not at the dealer$$$$.

" they would have seen the broken bolts a long time ago. I know I would have."

Really, you need to know the bolts are susceptable to breaking BEFORE it happens, Also, how would you have seen the broken bolts since the flimsy heat sheild covers them, until the heat shield rusts away?, but thats another problem.

For the future, I think an Alldata subscription is in order for every car/truck i own, just to keep current.

still love my H2


2003 Green
all stock
with broken manifold bolts and a rear license plate tray, the black thing, where factory tape and a plastic clip dont cut it, but thats another repair.

[IRA51]

exaust manifold bolts break on all vehicles ,it's no big deal to change them . make sure you don't over tighten the new ones ,the heads are aluminum and you don't want to strip them . FYI my H2 has not done that yet in 85000 miles . this could be your excuse to install headers .