High pitched squeal

[ghostrider]

I have noticed recently that upon startup, when the car is hot or cold, there is a high pitched squeal that comes from the pulley side of the motor. It's a 91. I've done a little reading and have heard that it could be a belt, or to much tension on the belts. Now I don't believe it is any of the accessory belts being old and slipping, because the belts were changed about 20,000 miles ago. I don't know about the tension though, since I didn't change them myself. Probably not tension either because it just started doing this. I've also read that it a bearing in one of the pulleys, or maybe even the timing belt. The squeal doesn't happen all the time. And I don't know how to make it happen. Any idea on how to figure out where the the sound would be coming from. Or what to look for.
Sorry so long. Later

 

[jthomas68]

Usually it`s a loose belt.Take a look at them though,if it slipped to many times it may be glazed over.

 

[JonVH]

I have something similar but only when it's first started & has rained or is damp out. I believe it's moisture related to the belts. Not sure what the fix is other than maybe I need new belts.

 

[ghostrider]

Well I can try and see how tight or loose the belts are. The only thing is though that I have messed with the belts of a car in quite some time. Also I don't have a belt tension gauge. How much should the belts give when you press on them. 1/4 inch, less, more? I used to be fairly confident at working under the hood of my car. I just haven't done much for way to long.

 

[ret]

You could also try belt dressing. Only costs a couple dollars at any auto parts store. Squirt it on your belt by the pulleys and run the engine a bit, it will help keep the belt from slipping and squealing, if it's not too far gone.

 

[ghostrider]

Well this afternoon on my lunch break from work, I was able to take a look at the belts somewhat. As I'm sure all of you know it isn;t to easy to gain access to the belts. Anyways, I was able to mess with the alt/AC compressor belt. It felt kinda loose. And also when I started the car I jumped out so I could get a better listen to it squealing. I revved it up a couple times and the squeal is definitely coming from that front set of pulleys. Can't tell if its the alt pulley or the compresor pulley. **** I'm not even sure if it is the compressor pulley that is below the alternator. Now the $64,000 question is, how do I gain easiest access to these belts, and where is the tensionor? Thanks for all the help.

 

[89 Gary]

The tensioner is to the left and down. To adjust you must loosen the nut on the tensioner and above that you'll see an allen nut which you turn righty to tighten tension and lefty to make less tension. After getting your desired tension tighten the nut-don't strip it! I do believe you'll have to take out battery first but not the tray as I did it last week.

 

[sdpatt]

You can reach the 14mm nut at the center of the 6-rib belt's tensioner pulley with the battery in place. Just use a box end wrench and slide your arm down aft of the battery. Loosen the nut about 1/2 to 3/4 turn. Use a 5mm Allen wrench, socket or tool to turn the tensioner screw on the top of the tensioner bracket clockwise to tension and counterclockwise to loosen the belt. There should be enough tension to prevent the A/C compressor from causing a "chirp" when it engages at highway speeds. You can also get a ballpark tension setting by pressing on the longest span of the belt (between the damper and the A/C compressor) and checking the amount of deflection you can cause with a firm finger push. There should be no more than 1/4" of deflection. When the tension is set, the tensioner pulley nut only needs to be tightened to 25-37 lb-ft.

 

[ultimatesho]

mine is also doing the same thing.......only on cold start...reving stop it quicker.....belt tension feels to be good but i could be wrong.......the bottom side of the rear belt has like a black sludgy oily substance on it...no smell at all........any input?????

 

[hawkeye18]

cold rubber = less grippy. Hot rubber = more grippy. Cold belt = slipping. Slipping = friction. Friction = heat. Heat = hot rubber.

Everybody follow me? Your belt is a little past the edge of too loose. When you start the car, the belt does not have the tension (the grip) to rotate, more than likely, the alternator pully, since it has the most drag at start up. The water pump is also likely, since it has the least belt contact.

Anyway, when it slips, it makes that god-awful noise. That noise is the belt rubbing against the pulley and creating heat in the belt. Once the belt gets hot enough, it has enough grip in it (ever put one of those pink erasers in the fridge? good luck erasing anything with it afterwards!) to finally overcome the drag of the pulley, and once it begins moving, it presents much less inertial drag (Newton's 1st law of motion: object at rest wants to stay at rest...) and doesn't rub against the belt. The noise goes away!

Change your belt. If it's been 20,000 miles it's due anyway. You're supposed to change them every 10-15,000 miles, no? I do. I like my water pump spinning thank you!

 

[SHOdownTN]

Just a shot in the dark, by his description i'm gonna say he has a bad idler pulley.
While the belt is off check all the idlers for play and spin them, see if they feel rough.
Had one bad on mine when I bought it. It went zzzzzzzzzzzzz Kinda sounded like a turbo or something. When I bought, it the previous owner said the power steering pump was bad and squealing.

Hope this helps, you will know real quick after you chage the belt........

 

[Bishoptroy]

i had this problem but it was almost all the time, it was the actually tensioner pulley itself squealing not the belts.