HORRIBLE squealing under hood.

[Unofficial]

Last winter and even in the spring and fall, when it's cooler out, my truck will squeal like crazy when I start it up. It's odd because sometimes when I try and start it, the starter will turn over for a couple turns and just run on... It won't fire up. I give it gas while starting and it fires up but there is a terrible squealing under the hood. It's WAY too loud for a belt squeal, and it gets louder with RPMs. It must be putting a drag on the engine too, because it will stall quite often. For the stalling, I got a new IAC valve, and it runs better, but still stalls when slowing down and putting into drive/reverse. I can't think of anything else. I've replace the alternator, power steering, and the p/s belt. Can anyone think of anything else that will squeal like this?

By the way, it's a 350 TBI

[Prong]

Checked the water pump bearings? They can do that.

[zieg85]

You would be surprised how loud a loose PS belt is, but I am sure you have checked that already.

[DnStClr]

Well that's kinda weird that it only squeals during cool weather. I was gong to suggest a bad a/c compressor clutch.

[Lt.Del]

any bearings will put a load on the engine, even the alternator bearings.  I had to rescue a buddy of mine while he and his wife drove down the interstate.  The engine just seized up.  They coudln't figure out why.  They tried starting it but the battery wasn't powerful enough.
Turned out to be the alternator had seized.  That, in turn, seized anything associated with the belt--since the belt couldn't move. 

I say take your belt (s) off the part (water pump, alt, power steering, a/c) one at a time and turn the pulley of that part with your hand and see if you can find out anything. See if it wobbles, or if it doesnt turn smoothly, whatever. 

[Unofficial]

My alt. pulley was squeaking when I turned it with the belt off, so I replaced the alternator. I also replaced my power steering pump and belt. Won't my water pump leak or something before going out?

Also, is there any way it could be my harmonic balancer? I'm pretty sure the rubber ring is bad and the outer part slipped. The reason being is because when I tried to time it, I put the mark on TDC and it wouldn't even run...

[Donut]

Water pump will usually leak before going, I just changed mine because I noticed a shaft wobble before any leaking started.  If the balancer ring has slipped, it wouldn't hurt to change that also.  I can just imagine the damage if the outer ring came off.

[DnStClr]

If you suspect that the balancer rubber ring is bad you should get a new one. You know, if you can move the outer ring it's not good. You getting vibration while the engine is running?

[jimbo]

Sounds like you have been replacing things without truly finding the culprit first.  I would take all the belts off and crank it. Then start from there if it does not squeal.  Install one belt at a time, check all pulleys, etc.

[DnStClr]

I agree. That's the way you should go.
BTW if you get to the end and the squeal is still there, don't forget to check the distributor for a rusty bearing.   

[joesgarage71]

I agree. That's the way you should go.
BTW if you get to the end and the squeal is still there, don't forget to check the distributor for a rusty bearing.   

Don, distributors have bushings
 TBI huh, loud squealing, makes me think it has a bad belt tensioner

[Irish_Alley]

TBI huh, loud squealing, makes me think it has a bad belt tensioner

x2 it would seam to me like the tensioner is OK till it has to work against thick power steering fluid causing it to squeal. buy a stethascope from autozone or advance and put it on the bolt that goes to the belt tensioner pulley the go to the alt then water pump then powersteering pump and see where the noise is louder. or you could use a long screw driver

[DnStClr]

Ha. And I just replaced mine! thanks for correcting, Steve..

[eventhorizon66]

I thought '87s still had V-belts.

[gold84gmc]

mine isnt a LOUD squeal but when its damp or wet outside and my truck is idling the belt(s) (i think is whats making the noise) squeal a little bit...but they only do it when its wet out and when its idling