dcollins3208

Voltage plummets when it does this. Did a preliminary check and the belt looks fine, isn't loose as far as I can tell. When the rain subsides I'll check further but in the mean time what do you fellas think it could be? Dying alternator, bad idler bearings, etc? It only does it maybe once every 5 startups and the voltage drops off, then once the squealing stops after about 5 seconds everything is back to normal

Robert_B

Sure sounds like a pulley is froze. If it's not obvious from visual exam, you may need to remove the belt and spin each by hand to see if there's a bad one. That's what I'd do first, anyway. How far does the voltage drop?

bowlingballhead

I've had this exact belt squeal, followed by voltage drop, sometimes accompanied by GEN light coming on. Have had two new belts on, and the water pump replaced. I'm almost certain it is the AC compressor. It usually only squeals when engaging the compressor in any of the AC modes or defrost. The AC works fine, so I'm going to wait until it dies to replace it, as the squealing only comes about every once in a while, and then it subsides rather quickly when you start driving.

RRXJeeper71

same here, My alternator bearing seized like a ****
little noise at first, just got worse till the alt seized completely
bought new alt, and belt, problem solved!

nakosd

If you have your AC turned on when you start the engine, then that is probably the source of the squealing.

The squealing is simply the belt slipping, because the "pully" on the AC is actually a clutch and it will engage and disengage the internals of the AC compressor if the AC is switched on or off. That's why your voltage drops on startup because the belt movement is being sapped by the AC clutch.
When I start my car for the first time on a hot day, I'll toggle the AC on/off with the Fan power setting to 1, until i get no squealing and then go to full power. I don't know if its the AC clutch or the internals of the compressor, but a long enough time period of non-use seems to make the AC a bit stubborn.

A squeaky alternator bearing is also a valid option, and I've occasionally had both the belt and the alternator bearing squeaking at the same time. If you can afford it, never buy the bottom of the barrel alternators, i think the brand is called Ultima, and I've used one of these to replace the stock alternator after it started giving me intermittent failures. The new alternator ran perfect right after the install, but it started squeaking the very next morning, and it kept squeaking for months. They have crap bearings in them and they take a long time to break in. They are a guaranteed squeak after rain.

I'm gonna opt to have my ac compressor rebuilt by next summer or simply replace the ac clutch because it makes my engine run a bit rougher.

Ill also add that most of the time you can fix a slipping belt by increasing the tension. Press your left hand against the longest straight section of the belt (usually on passenger side running down from the AC, and it should not move more than 1-2" with the force of your fingers. The belt tensioner on the 2000 is located on the driver side, the bolt head faces towards the passenger side. You have to loosen the large nut on the pulley attached to the power steering to be able to change tension on the belt. Usually only one or two full turns of your socket should be enough to fix belt slipping. Be careful because your wrench might be right next to the cylinder head's water intake and it can be just hot enough to burn the hair off your hand

DFlintstone

The squealing is causing friction to make heat. (sort of) After it's been squealing good for a bit, shut it off and feel around for something warmer then the others. In a lot of years over allot of miles, the only bearing I've had trouble with is the idler. Oh, and once I needed to soap & clean the belt, it had something on it. Once well rinsed it quieted down.

carbuff

Tighten the belt some more. Ive found the belt needs to be very tight on these engines. Thats how I finally got mine to stop squealing. New alt, new belt, didnt stop til I tightened it a lot.

dcollins3208

All the pulleys/bearings were good to go, tightened the belt and the squeal hasn't been back since. Does anyone have proper tightening specs for the drive belt? I couldn't seem to find it in my Haynes manual and I don't want to destroy all the bearings from tightening the belt too much.

toasterknight

I have always said go until you think it's tight and then tighten it a bit more. These like the belt tighter than most mechanics will do it.

t.mcginley.jr

Usually there's no torque spec or anything on belts, sometimes they give a deflection rating though. So they might say it's tight enough when there's 1/4-1/2" deflection when applying this much pressure. Pretty sure there's a special tool for it, but seems like a waste of money.

When grabbing part of the belt and trying to move it up or down, you shouldn't be able to move it very far. If you can move it more than 1/4" or so, it's too loose. If you make it WAY too tight though you can wear out the bearings in the alternator, water pump, etc.

dcollins3208

Thanks I appreciate the info. Just to update, tightening the belt has indeed stopped the squeal