Is this a loose serpentine belt?

[Skant]

Today it started making moderately loud noises when I turn the wheel on my 1996 LT4 vette. When I'm just sitting there and turn the steering wheel, it makes this noise from the engine that sounds like... hard to describe I guess. At first I thought it was coming from the tires because it's a rubbery ticking/rubbing sort of sound. Kindof like rubbing taught balloons together roughly maybe.

I opened the hood and listened while my friend turned the wheel. At first I thought it sounded like something was contacting the serpentine belt when the power steering was active. But now I'm thinking it's the sound of the belt slipping/gripping/slipping/gripping rapidly.

I'd guess when you use the power steering, the pump puts more strain on the pulley.

I'd be pretty sure it was the belt except that the sound is nothing like the belt squeal I'm used to. But then I'm used to older V8 motors that don't have serpentine belts.

Visibly, the belt has little cracks and appears to be toward the end of its life span. So I'm guessing that's it. Just I've never heard that sound from a belt before.


Second question... The belt looks like it goes around what I think is the power steering pulley backwards. I believe there are three accesory pulleys down there and two idlers... the alternator and A/C are up top (clearly visible). The lower one must be the power steering I think. The pulley on the power steering is slotted to mate with the bottom of the serpentine belt, but the belt actually goes around it the other way so that the non-grooved side (top) of the belt is against the pulley.

Visibly, it looks like the belt would reach around the pulley either way. But I doubt the power steering would work at all if the pulley was going the wrong direction. Is this how it's supposed to be? That could certainly explain why it's slipping if it's not supposed to be pulling with the smooth side.


Third question... is it difficult to replace the belt on an LT4? Not much clearance in there at all. I'm hoping I don't have to take stuff apart to get at it.

Thanks in advance!

PS: Searching through the forum posts, I see references to 'morning sickness' for the power steering. But the engine was not cold and it wasn't a cold day. And I'm not sure that I would describe it as a moaning sound, though maybe it could be. And other than the noise, the power steering seemed to be working fine. But maybe that's what it is anyway?

- Skant

 

[sumoboy]

Any kind of oil residue will make a belt sound like it's grinding especially at the power steering pump. How many miles depends also, I would replace it and check the idler pully bearing.

 

[aussie]

belt noise

if the belt is touching the pump on the flat side my guess is some one has installed it the wrong way .if you alternator is the same way or your water pump take it of & reinstall.not hard to do you dont have to pull anything apart the general has given you just enough room .

 

[Skant]

I replaced the belt today. The old one was installed correctly. But did have some cracking.

Unfortunately, the new belt did not fix the noise.

Any other ideas about what might be causing this noise?

It doesn't seem like I lose power steering while it makes the noise. Just if I sit on dry pavement and turn the wheel to the left and right it makes the noise. Basically, when the power steering has to work harder.

I'm still hoping it might be something simple...

- David Peterson

 

[Skant]

I tried bleeding the power steering system using the procedure where you lift the front of the car and then turn the wheel lock to lock 40 times. There were still some air bubbles coming out of it at the end, and it didn't seem like it was actually going to stop. Plus the fluid is semi-opaque and light tan in color which I believe is a bad indication.

I took it to Corvette Connection to have a listen, and they told me that the sound was definately the belt slipping. They were a bit perplexed (as I am). The new belt is tight and... well... new. It shouldn't be slipping anymore. They pointed out that the top of the belt (the part that runs against the power steering pulley) shows unusual wear marks... which is especially unusual for only being a few days old.

I did clean the power steering pulley, btw, on the suggestion that it might be oil residue. I did it with the old belt on by running the engine and carefully setting a towel against the pulley as it turned. It wasn't very dirty. And it didn't fix the problem.

We theorized that it must be slipping because the power steering pump is requiring excessive force to turn when I'm turning the steering wheel with the car at a stop. Which would indicate a bad power steering pump somehow.

So I made an appointment to have the power steering pump replaced and the system flushed on Thursday.

This morning, though, I had a thought... could the steering system be binding somehow? And thusly the pump really is having to work too hard? Could there be another cause we're missing here? Would the power steering pump be too hard to turn even if the steering was having to push too hard?

I don't want to dump the chunk of cash on replacing the pump only to find out it was something else.

Does seem the likely culprit though.

- Skant

 

[carguru]

Have you checked the harmonic balancer? I have a '95 Impala SS that is doing the same thing as you described. Both Corvettes and Impala uses the same harmonic balancer. The rubber in the harmonic balancer disintegrated enough to allow slippage between inner and outer rings. Check yours with an alignment mark near where the belt rides and the inner part. They should not drift apart. Good luck.

 

[vigman]

Skant.. try the following

Last ditch experiments..
Is anything leaking in the power steering system?

Sometimes when you turn the wheel full lock.. you get a similar sound as a belt squeek.. but it's the pump cavitating.. and there's not ALOT you can do about that, but that ONLY happens at a FULL LOCK of the wheel.


1) Get a turkey baster and suck all the old fluid out of the power steering resevoir.. ( you will only get about 1/2 of the total system.. but that's ok).. refill with new. ( might want to add some power steering conditioner fluid while your there...) drive it around to mix the fluid up.. did the problem minimise? Inspect the newer fluid is it still yucky.. do it again.

2) Take a look at what the tensioner is doing as your turning lock to lock with the wheel..is it jumping, jiggling.. your tensioner MIGHT be a little weak in the spring. Remove the belt ( again ) and check the idler roller... bushing dry? lots of play there?
Give it a squirt of oil in the bushing area for the roller.

3) Some of my cars squeek no matter WHAT I do... for grins.. I use belt dressing.. which is an oil based product.. this softens the belt up a tad.. and lets it grip a bit better..

If you can't find that.. a candle will do ( BE CAREFUL WHILE DOING THIS) with the engine running.. drag the candle on the belt
(both sides).. and let the wax get on the belt.

Let me know.

Vig~

 

[RedRagTop]

I think on my 88 there was a sevice bulliten issued regarding this problem (enter corvette service bullitens in your search engine) but you would think that by 96 that bug would be worked out. As I remember, this bulliten had to do with relacing the tensioner with a replacement GM part. Rack&pinion degredation will show discolored power steering fluid, mine does and I will be flushing system in spring for hopefully quick short-term fix. RJS

 

[Skant]

Thanks for the tips. We did check the other possibilities before replacing the pump. But the culprit did indeed turn out to be the power steering pump itself. Replacing it fixed the problem.

It was nice to have some alternatives to check. But checking them turned out to just make it more certain where the problem really was. Which was good piece of mind because replacing the pump isn't cheap.

- Skant

 

[Daryllawman]

I have found on other cars and trucks that are making a noise, if you put a little WD-40 on the pulley while the engine is running and the noise goes away for a short period of time,,,,,,,,Then its your belt and the only way to get rid of the noise is to replace it.......