Z01Vett

Hey Gang, I just picked up my '02 Z06 last week; there's an intermittent squeaking coming from somewhere in the serpentine belt pulley system along with what I can only describe as an intermittent rattle/knocking sound coming from the front of the engine.

The sound isn't a constant tap-tap-tap nor is it rhythmic; it almost sounds like something's loose and rattling against something. One of my buddies thinks it's a bearing going out - the dealer said he thinks the water pump is going. He said he took off 2 pulleys and repacked them but the squeaking noise didn't go away.

I've searched threads and I understand the pulley system has issues but I've not come across anything that describes this rattling/knocking noise. I've taken a video of the engine - if you listen closely you can hear the rattling/knocking sound.

Has anyone come across this noise and if so what do you think it is?

Also, I haven't found any threads on how to diagnose the pulley system to pinpoint the problem; some posts recommend taking the AC belt off to see if that's where the noise is coming from and go from there. Is there a troubleshooting procedure for checking all the tensioners, pulleys and accessories?

My Z has 85k miles on it; would it be good practice to replace all the tensioners and idlers along with a new belt? I've read the Gatorback is the best belt.

I did get an extended warranty but before going that route I'd rather try and take care of this myself.

One last thing - I can't find a Haynes or Chilton service manual for the C5 - does anyone make one?

I love my Z but it's embarrassing driving it around with it sounding like a beater with a loose belt

Thanks in advance for the help - here's the link to the video:

marty mar

First thing to do is remove Both belts, run the engine and make sure the noise is gone..... Hopefully after the noise is gone, put just the AC belt on again and re check. If there is still no noise, put the serpentine belt back on and have a competent mechanic listen with a stethescope instead of guessing with your wallet. good luck. Ps double check the harmonic balancer, they are a known problem with the C5.

Bill Curlee

I agree with removing the belts and see if the noise stops.

Go to the auto parts store and purchase 4 feet of 5/16" vacuum line.

Two ways to do this:

Put one end of the line in your ear. Point the other end towards the noise. Move the end around each rotating assembly and if the noise gets louder, you have zeroed in on the source

Shove a metal bolt into one end and of the tube (about a 1/4". Touch head of the bolt to the body of each pulley while you listen to the other end of the tube. The offending part will sound off loud and clear!

That way you can pin point the bad bearing.

I use a purpose bought mechanics stethoscope which has a long thin metal shaft and I have a regular doctors stethoscope. Both work excellent.

Bill

CMC Corvette

I saw that so many of you had success with the Goodyear Gatorback belts that I got one (the main belt; stock # ends in 798) and put it on my 2001 5.7L. THE NOISE IS GONE; HOWEVER---- While replacing the belt, I noticed that as I would release and apply the belt tension on the main tensioner pulley (top of engine, passenger side), that the pulley would turn slightly sideways. (Tension off, the pulley would be straight; tension on, the pulley would go slightly sideways again.) Even though the new belt eliminated the squeak/squeal, I am convinced that the pulley was the main problem and I did not want a pulley out of line. I have just replaced the tensioner/pulley ($40 for the part). It took me less than 10 minutes to get the belt off, unscrew the two tensioner/pulley bolts and remove, and replace with the new tensioner. I've got a total of $60 in the belt and tensioner/pulley.