This is my first post so I hope I can get enough information to get a proper answer. I have a 2000 convertable with a stock LS1. The car has roughly 70k miles on it. I replaced the belt tensioning pully about 3 years ago (maybe 18K miles ago) along with the serpentine belt (it fell off somewhere on the freeway when the tensioning pully decided to give way) Now to the problem, the squeal that is coming from under the hood is constant regardless of spreed and RPM, (it changes pitch when the motor reves but otherwise it is consistent) it is so loud that I can hear it with the radio on while driving at highway speeds. I was told that it is squealing likely due to slippage and that I need to apply a belt conditioner. I bought a can of CRC belt conditioner from schucks/O'reileys and was told to apply liberaly to both sides of the belt with the engine running. I did this and the noise not only did not stop but got MUCH louder. The next day I decided to apply a silicon spray to see if I could quell the noise and to my thrill the noise stopped entirely. That was until last night (a mere 24 hours after application of silicon) I was driving in the rain (I live in Seattle so this is no shock) and after about 15 minutes the noise started again. I attempted apply the silicon again but this time it did no good. Additionally I read that the belt may be "glazed" so I took a very fine grit sand paper (600 I think) and scuffed the surface (non grooved side) and both sides of the belt lightly. This also did not help.

Is there anyone out there that can lend a hand on this? I love my car dearly but when I drive it I feel like I am behind the wheel of a beat up pinto or something due to the noise.

 

It is interesting that you had some success with the silicon spray, but later it failed. Perhaps you squirted some on a bearing somewhere, which is what I am thinking may be the problem. I'm sure you will get a lot of suggestions soon, but probably replacing the belt with a Goodyear "gaterback" can't hurt and end that issue. Good luck!

 

I had a mild case of squeaky belt syndrome,and 2 Goodyear Gatorbacks cured it permanently.

There are 2 more belt tensioners on the A/C belt (way under the front of the engine,passenger side) ,but if you sprayed the main belt and the noise quit,they,or the A/C belt, probably aren't the problem.

Belts are like brakes-putting a lubricant on them to stop a squeak is not really your best choice,IMO,plus it's a very temporary fix...

Welcome to the forums !-Hang out,get to know the place,lots of helpful,knowledgeable folks here,If you need to know something about your Vette,chances are you'll find it here-

"Search" can be a very powerful learning tool also

 

Check the harmonic balancer for movement. Easy way to find out witch belt, remove one belt and start the car . No squeak thats the one if still hear it its the other belt.

 

Hey Carcass and Lucky99,

Thank you for taking the time to reply I will likely replace the belt however the one thing I guess I should note is that my car is a single serpentine belt system not a dual belt system, I assume this was the setup on the 1997-1999 C5 models possibly?

Although before I buy a new belt I will likely just take off the one that is on there and run the engine to see if the squeak stops...if it does I can assume it is the belt and not a pulley.

 

I'd say you just have a stretched belt. My symptoms were no where near as extreme but a belt change cured my squealing. And a top tip, Gatorback belts are way cheaper than OEM.

You can probably reduce or even fix belt squeals with lubrication or belt dressing but it will probably return quickly. A belt change is the easy fix but you need to make sure that’s the issue.

ET who was one of the C5 design engineers posted a great summary of the system and I’ve copied it below. Run through that procedure to identify where the problem lies. If it’s a belt that’s good news and is fairly straight forward once you work out the technique.

Let the engine cool down first or it gets painful. Identify the main belt tensioner from the picture. It’s the top pulley on passenger side. Place a socket wrench on the tensioner nut and push it toward the middle of the engine until there is enough slack to remove the belt. Repeat this procedure for the A/C belt, although the tensioner is a little harder to reach because it is under the power steering fluid reservoir.

Once you have them off its worth cleaning the pulley with a wire brush.

Putting them back is the reverse process but make sure you install the A/C belt before the main belt.

Here’s a pic to identify the components.



Belt Squeal Courtesy E-T

You have two belt systems on your car. One is the drive belt system, the other is the air conditioner belt system. The drive belt system consists of the serpentine belt, the power steering pump, alternator/gen, water pump, harmonic balancer, idler pulley, belt auto-tensioner pulley. The AC belt system consists of the compressor, harmonic balancer, idler pulley, belt auto-tensioner pulley.

First thing you need to do is isolate which system is squeaking. This can be done by releasing tension on the drive belt tensioner and removing the serpentine belt. This is the outboard belt of the two belt systems. If the squeak goes away, then it’s the belt or a component of the drive system.

If the squeak is still there, then it’s a component of the ac belt system.
To verify this, release the belt tension from the tensioner and remove the belt. If the squeak goes away, then it’s a component of the ac belt system.

A common problem is the belt tensioner on either system but verifying which system is at fault is the proper procedure.

You could replace both belts, but you may still have the squeak. If you want to find the culprit, isolate the system, then spray the belt of the offending system and see if the squeak goes away. Try to stay away from the idler and tensioner while spraying. I find that belt dressing may be good to identify a belt problem, but it is a temporary fix at best.

The real problem has been the tensioner and the idler. Both of these components have a sealed bearing which has been know to dry up or redirect the grease away from the bearing, thus causing the squeak.

If you find that a belt change does not correct the problem, then a change of both the idler and tensioner pulley is in order. If you just change the idler or the tensioner alone, it will cause the other component to go bad in a month or so. This has been the case with many members. There was a change made to the dusts seals to help correct this problem in newer C5's. Lots of tensioner and idler pulleys have been identified as a problem and it can affect either system. One is not more prevalent than the other. So find out which system is squeaking first, in the drive belt system. It could also be the bearing of the alternator, power steering pump, or water pump too, but these are less probable.

 

Very thorough reply,DeeGee !

I just want to point out to the OP that I didn't know there was a second belt on my 98 till I'd owned the car for about 6 months- If you don't know where to look for it,you'll never know it's there.
When you do find it,say a prayer that the A/C compressor never goes out-the belt is easy to change,the compressor, not so much...

 

Following up on DeeGee's post...
If you remove the lower belt, (it powers only the AC) and drive around, it will help diagnose the problem.

Squeel continues means the problem is on the main serpentine system
Squeel is gone means it is on the lower A/C system.

Once you have determined that hand spin each pulley on the offending system.
They should move smoothly and spin freely. IF they feel "gritty" wobble or don't freely spin, you have identified the problem.

Once you have eliminated all other pulleys that you can spin, you are left with the problem being either the harmonic blancer on the main system or the A/C clutch pulley on the lower system.

 

I went through the same thing with my 99.... my initial problem was the a/c idler pulley.. I replaced it and put 2 brand new Good Year Gatorback belts on... One drive belt and one a/c belt.. Guess what?? About 3 weeks later the squeaking starts again.. I thought it was coming from the drive belt tensioner pulley, so I replaced that pulley.. Guess what?? I thought wrong(bonehead).. it was the a/c tensioner pulley squealing the whole time So i replaced that one.. Finally no squeaking!!! But wait... its not over yet... Guess what happens 3 months later??? Can you say squeak squeak squeal? Yes,,, It was the drive belt idler pulley this time... Replaced that one and thank god there are no more pullies on the engine.. What a nightmare.. If you pull the cover off any of these pullies and expose the bearings, you will find them bone dry... I did some research on them and they are made in China.. Damn communists!!

 

If its the belts that will be a good thing .I had a 99 and it had the same issues that you are describing .It turned out to be the Harmonic Balancer . This is not an uncommon problem .I replaced the balancer and all was good .. Hopefully for you its just a belt ,but I would take a good look at that balancer.. Good luck

 

Hey I'm in the Seattle area (Redmond) and have a 99 that's squeeling bad too. After replacing the belt, and a tensioner pulley I took it to Kirkland Classic Cars where they diagnosed it as the idler pulley. My belts were also being stripped on the side because of it. So I have an appt with them this week to get it fixed. Will let you know how it goes!

 

I posted about the problem a couple of weeks ago.

What's working for me, so far, is to dampen a shop towel with general-purpose automobile cleaner (Meguiars brand) and hold the damp cleaner-laden cloth against the main serp belt at the alternator pulley (Carefully!) while the engine is idling.

Doing this the first time transferred a large amount of black residue to the cloth, and revealed the white printing on the belt. And made the squeal go away.

The lack of squeal lasted about 60 miles.

Forging ahead, I repeated the process, removing another large amount of black residue from the belt.

This time the treatment lasted about 100 miles.

I repeated the process one more time. So far, it's been a little over 300 miles and the squeal hasn't returned - yet.

I don't know why this works; maybe the accumulated detritus of a deteriorating belt lets the belt slip; maybe I've soaked the belt with enough automotive cleaner, it hasn't all evaporated yet. But cleaning a dirty belt definitely makes the squeal go away for a while.

 

I did some research on them and they are made in China.. Damn communists!![/QUOTE]

Love it. Where they Red pulleys?