harmonic noise 1400 rpms

[SigGMC96]

I have a similar noise on my 96 k1500 but I only notice it at idle. I crawled around underneath while it was running and found that it was the crossover pipe from the exhaust manifolds to the cat's, its just barely touching the bottom of my transmission and if I take a chunk of wood and pull it away from it the noise stops. I just havent been bothered to replace the pipe since its not really causing any harm other than the irritating noise.

[J-Ri]

Originally Posted by SigGMC96

...I just havent been bothered to replace the pipe since its not really causing any harm other than the irritating noise.

It's probably getting the tranny pretty warm. Heat isn't exactly good for trannys.

[Jackie Morris]

Originally Posted by SigGMC96

I have a similar noise on my 96 k1500 but I only notice it at idle. I crawled around underneath while it was running and found that it was the crossover pipe from the exhaust manifolds to the cat's, its just barely touching the bottom of my transmission and if I take a chunk of wood and pull it away from it the noise stops. I just havent been bothered to replace the pipe since its not really causing any harm other than the irritating noise.

I think I have narrowed it down to the distributor, I think it may be allowing the shaft and gear to lift a little bit and the gear mess may be what I'm hearing. I can hear it by holding the motor at 1700 while under the hood. maybe this weekend.