2003 Chevy Avalanche Drivetrain Rattle

KRASHFREEWAY

MEMBER
2003 CHEVROLET AVALANCHE
V8
4WD
AUTOMATIC
99,500 MILES

I have a 2003 Z71 Avalanche with 99,500 miles on it. Just recently, I very metallic rattle coming from below the truck while driving. It was a low frequency at low speeds, and increased in frequency until about 25mph, and then went away. I figured it was a heat shield that broke loose, so I looked underneath and everything seems secure. The noise is not made if the truck is being revved in park. Only while driving - I think that rules out the cat/exhaust. It happens in 2WD & 4WD. Any body have a similar issue?

Thursday, February 26th, 2009 AT 4:36 PM

3 Replies

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Have you taken a rubber mallot to the exhaust?

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Monday, March 23rd, 2009 AT 5:01 PM

KRASHFREEWAY

MEMBER
2 POSTS

You think its the cat? I though about it but haven;t done anything about it yet. I did find out that my u-joint's trashed though

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Wednesday, March 25th, 2009 AT 2:46 PM

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi:
If the u-joints are bad, I would start with them. They could cause that noise. As far as the converter, sometimes the guts in the converter break loose and rattle. Not only is it a pain, it can cause engine trouble.

Let me know about the u-joints. If they are that bad, chances are that is the problem.

Joe

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Wednesday, March 25th, 2009 AT 8:48 PM