Which belt is squealing?

Hi guys,
I have a 1985 Chevrolet Cavalier, 2.0L 4-cylinder, automatic.
It has two V-belts.
Belt #1: Water pump, alternator.
Belt #2: Water pump, power steering pump.
One of the belts has been squealing but I cannot determine which one.
Both belts are tight enough and are nearly new.
The car has a new water pump.
The squealing happens when I first start the engine - cold start, and lasts 10-20 seconds. It may not squeal if I start the engine within 12 hours of turning it off. It is guaranteed to squeal if it sits for more than 24 hours. Hot weather makes it worse.
When the squealing stops, engine RPM goes up a little.
I have put some masking tape on the alternator and power steering pump pulleys to see if maybe one of them is not turning while the squealing is happening, but they both turn.
I should also say that the battery is about 13 years old and may be putting a large load on the alternator. Otherwise, the battery works fine.

Short of removing one of the belts, are there any tricks to determine which one is doing the squealing?


Get a spray can of rosin and spray it on the underside one belt. This will make it stick better to the pulleys and stop the squeal if it is the belt. If that doesn’t work, try the other belt. If that doesn’t work, it isn’t the belts. It might be the bearings in a pulley.

Thanks. Rosin spray - is it an automotive product? Where do I get it?

I just spray them with water. Belt dressing is sticky and hols dirt. This causes premature belt wear.

The water makes them slip more?

It might be possible to loosen one of the belts enough so it doesn’t turn at all and see if that makes the noise go away. If the noise remains, it must be the other belt. Some caution is in order, b/c depending on which belt you loosen, you might not have any coolant flow or power steering or working alternator, so only do this test for a brief time, certainly for less than a minute, to avoid damaging something.

If it turns out to be the alternator belt, probably a good idea be to have the battery load tested.

A 13 year old battery, is that a typo? Might be a good idea to buy a new one.

Water may allow the belt to slip more, but it will dry back out in minutes…if not less.

The idea of water is to give the belt a temporary lubricant (for a moment) to eliminate the belt as a source of the problem. Once it is determined that it is the belt or not it will dry back out in short order.
Anything else applied to the belt for testing would last much a longer time and interfere with further testing.


Thank @Yosemite. Water only stops the sound for a second, but it tells which belt to replace.

Yes, if you spray water on it and the squealing stops you know it has to be the belt, or the pulley’s that it rides on.
If the Squealing continues, you can investigate the pulleys.


A 13 year old battery, is that a typo?

Nope. The manufacture date is actually March 2001, so it is 14 years old. It was one year old when I purchased it.

It is an economy battery from either Advanced Auto or AutoZone, I don’t remember which. Made in Mexico.

I guess you can say I got my money’s worth out of it.

since the battey is 14 years old i am assuming that youve been taking care of the maintanince on the battery. if not i would recomend you bringing the battery to a place that can check the battery, just to make sure its still giving off 12v. the alternator can be tested as well just to make sure its working properly. squeeks can be cause by seval things tight belt, belt slippage, and an engine that working to hard or belt is over 4 years old. for belt slippage the water will stop the squeek. bad batterys cause alt’s to go out which make the engine to work harde, same thing with old belts. tight belts causes the tenchener and pulleys to squeek.

but with the water stopping the squeek the belt is bad and needs to be replaced

I think I have the squealing isolated to the alternator using the water method.

With the belt being new and properly tensioned, the alternator must be worn out. It has to be at least 12 years old.

Even if the battery does draw a large current initially, I don’t think it would make it squeal as much as it does.

Sounds like you are on the right track. If the battery voltage is 12.6 volts or so with the engine off, then the alternator won’t be supplying much current to the battery, so you’d be right the current load on the alternator wouldn’t be the explanation for the sound. However, if the battery voltage is below 12 volts with the engine off, me, if there was no explanation for why the battery voltage was so low, I’d replace the battery first, before replacing the alternator. Or at least have it load tested.

Some big box retail parts stores will test your alternator for free, either with it in the car, or some can test it by itself, with a fixture they have, out of the car.

Since you’ll be buying the parts and doing the work yourself, I suggest an alternator with lifetime warranty

That way, if it fails in 3 years, and you still have the car, you swap it out for another alternator

That said, I wouldn’t be surprised if many of the parts stores do NOT have an alternator for your old car in stock

With the belt being new and properly tensioned, the alternator must be worn out. It has to be at least 12 years old.

I would think a “worn out” alternator that was dragging enough to cause a belt squeal would be making a horrible noise itself. Pop the alternator belt off and turn the alternator pulley by hand (putting a side load on it like the belt would) and see if you feel any drag, grinding, etc. Also, I’d replace that battery as a first step.