Weird belt system noise…….
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Joined: Jul 2022
Posts: 91
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Weird belt system noise…….
So just recently I started to notice what I thought was a belt going bad. Initially it was a chirping sound when I downshifted the car, and it grew to be intermittent whenever I got on the gas or downshifted. I figured it was the AC belt, replaced it, the sound is still there. *sigh* ok, I’ll just take the AC belt off completely to eliminate that system. I drove the car for a day with no ac belt, the sound is still there. I bought a new main drive belt, put that on, and cleaned the harmonic balancer and water pump. I also sprayed it with belt dressing. Still no joy. I also started to notice that the noise gets worse the longer I drive the car, and I can hear it chirp every time I go over a bump, as well as being extremely bad on downshifts. Seems to not be a problem on acceleration, only shows itself at cruise, idle (sometimes, particularly when I’m going over a bumpy road) and on downshifts.
I was initially thinking maybe the tensioner pulley, but I honestly have no clue at this point.
any ideas?
I was initially thinking maybe the tensioner pulley, but I honestly have no clue at this point.
any ideas?
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Try to isolate the noise. If you are sure it's coming from the front of the engine, get a decent length of vacuum hose to use as a stethescope at each pulley on the system. Long ago I had something similar on an LS1 Camaro, it was the pulley on the tensioner.
The harmonic balancers are a known issue as they come apart and can actually contact the front timing cover.
Another item that might cause something like this is the couplers in the torque tube.
Noises like this can be very difficult to diagnose because there are so many things that can cause them, and these noise seem to travel or carry through the car and engine bay. Dredded chirp can be caused by anything from a lose belt to bad pulley, manifold leak, bad lifter, torque tube, etc. Just have to isolate the sound and go from there.
The harmonic balancers are a known issue as they come apart and can actually contact the front timing cover.
Another item that might cause something like this is the couplers in the torque tube.
Noises like this can be very difficult to diagnose because there are so many things that can cause them, and these noise seem to travel or carry through the car and engine bay. Dredded chirp can be caused by anything from a lose belt to bad pulley, manifold leak, bad lifter, torque tube, etc. Just have to isolate the sound and go from there.
