kplange

I have had an alternator belt squeal on start up, off and on for a number of months, but it has become more frequent the past couple of weeks. I have replaced the belt twice. Once with a cheap belt and again with a top of the line belt. Both replacement belts are ribbed, while the original was not. I have adjusted the belt tension from sloppy to very tight, and everything in between, but it makes no difference. I've changed out the alternator, but that didn't work either. It is definitely the alternator belt as the squeal stops when I remove the belt.
I've sanded the pulleys as well as the belts. The pulleys appear to be aligned. The squealing occurs on startup when cold and lasts for anywhere from ten seconds to a minute. It also occasionally happens on startup for a few seconds when the engine is warm. Once the squealing stops, the engine's rpms increase slightly. As there is nothing else on this pulley, I don't know what is causing it to drag. The alternator spins freely and is not noisy. Any ideas?

Rob delta

Is your ac / AIR pump belt hooked up or missing? When my ac compressor went, I eliminated this belt and immediately had a squeal under hard acceleration and when the engine was started. I have changed the two remaining belts with correct tension and have almost eliminated the squeal. It only happens for a second after a cold start, and thats only if i give it too much gas immediately after it starts up. I believe if the alt belt went around the crank and not just the water pump there wouldn't be slippage. I recently started a post about this, but I got mixed feedback. So it seems that for now Im leaving it as is

edzolz

A redneck solution is to spray the pulleys with WD 40 while the engine is running. I know it sounds like it would make it slip more, but it actually will soften the belt enough for it to set deeper in the groove so it quits squealing.

Lady72nRob71

Have you measured the battery voltage while the engine is running? Needs to be between 13 and 15V. If the regulator fails and the alternator overcharges the battery, the load on the alternator is increased a lot.

What year and model?

Another thing is to clean the pullies with alcohol or lacquer thinner in case oil had got into the grooves.

kplange

rob delta, the air pump is hooked up and all belts are there.
edzolz, I'm trying to avoid using any short cuts such as WD 40 or belt dressing, as from previous experience, both make a mess of the engine compartment. This is proving to be quite frustrating though, so I'll keep it in mind.

kplange

Rob Young, it is an '81 Olds 98 with the 307. I don't have the equipment to check voltage, but I have replaced the alternator with a good used one, only to have the same problem

bigD

you might try changing the alternator pulley for a new one. i'd try a light treatment of beltdressing too...

hookem horns

x2 on what Rob said. Pulleys on the alternator or crank could be glazed from the slipping. Clean them really well, maybe brake cleaner on a rag (keep it off anything painted). You can get a cheap voltmeter at Harbor Freight for under $5 when on sale.

Mr Shifty Sidney

Are you sure you have the correct belt. This happened to me after I bought a car that had been sitting for a while. I replaced all belts and the alt. belt squealed. Long story short they had sold me the wrong belt. The belt was to narrow and did not fit the pulley correctly. You might double check your belt.

Good Luck,
Don W

Lady72nRob71

Okay, this one should have an internal regulator. So if you replaced it and have the same problem, it ~should not~ be voltage related.

Use some thinner or alcohol on a rag and clean the pulley grooves and the belt sides. And make sure they fit in the grooves. Cannot really trust what parts store computers recommend for older cars...

rustyroger

I had the same issues with my a/c equipped 307 Cutlass.

I replaced all the belts with new Gates belts, end of problem. I think Gates is an American brand, although mine were made in the UK.

I think the layout is a poor design in the first place, this problem keeps coming up on other forums.

Roger.

joe_padavano

There were hundreds of thousands of these cars built and only a small fraction have a squealing problem, so I doubt it is a design issue. I remain convinced that the problem has more to do with improperly tensioned belts than anything else. In particular I've found that most people do not tension the PS pump belt using the proper procedure. In my case, I have purposely run my 307s without the A/C belt to try and duplicate this squeal and have not been able to do so. I do take care to tension the PS pump belt using the factory procedure (loosen all THREE fasteners on the pump then use a pry bar between the pump nose and the tab on the bracket).

kplange

I've now cleaned the belt and pulley with thinner and installed a new Gates belt. Still no change.
This time, I had somebody looking under the hood when I started the car, as the squealing usually stopped by the time I got out of the car and got around to the front. He seemed to think that the squeal was coming from the pulleys on the engine as opposed to the alternator. I tend to agree with him. I'm still convinced that it is alternator related though, since removing the belt solves the problem.
In the mean time, I also tightened up the p.s and air pump belt and that seems to have improved the situation somewhat, although the car was already warm at that point. I still have to snug up the a/c belt a bit more, so will see if that solves the problem.
Otherwise, I guess it goes off to the local corner garage along with my checkbook.

jackedolds

Curious, what is the battery voltage during cranking and right at startup. Perhaps the battery is weak (weak cells or one bad one), but strong enough to start the car, and the alternator is full fielded immediately at startup. To see if this is occuring you could hook up a battery charger in start mode and see if the squeal is there on startup. If you have another known good battery lying around you could try that also. While there are more likely things causing the squeal - I have witnessed this occur and it doesn't take long to determine if it the cause.

Rickman48

Remove the belt, and hit the pulley with a stiff wire brush on the end of a drill - cleans and 'roughens up' the pulley at the same time.
From slipping, the pulley gets 'polished' and retains some residue from the belt, making it slip easier.

Lady72nRob71

Battery should drop no lower than 10.5V at crank, and that is with one of low CCA. The higher the CCA, the less drop ther should be.

CQR

Is your fan clutch fully engaged? or locked up? There isn't a lot of belt contact on the water pump pulley and if that is your drag then your buddy could be right. Maybe it is coming from the pulleys on the 'Engine'.

kplange

I had replaced the battery this past August with an 875 CCA one, so I'm going to assume for now that the battery is O.K.
When I started up the car cold this morning, I barely got a one second chirp compared to the usual fifteen second squeal, so I guess tightening the other belts have made a difference. I've yet to snug up the A/C belt, so I'm keeping my fingers crossed that this will solve the problem.

rustyroger

Well..... I've come across this problem on other engines, tightening the belt correctly or replacing a worn belt normally fixes it. It seems to be a hard problem to fix on this design layout which is why it seems to keep recurring. Simply tightening or replacing the belt is such a simple fix it doesn't get a mention for most other engines.
Rarely I have come across worn out pulleys, although I have seen wrong belts misdiagnosed as a pulley problem.
Running the alternator with a belt indirectly driven by the water pump pulley instead of a third pulley on the crank strikes me as a production cost cutting feature.

Serpentine belts with automatic tensioners seem to be making this a thing of the past now.

Roger.

kplange

Guys, Thanks for all the advice. This morning was my first startup in a long time without any squealing or even a chirp. I guess tightening up two of the other three belts have made a difference. It's been quiet all day, so I'm going to leave well enough alone. At least I have a trunk full of alternator belts that will last me a lifetime!