I decided to change the alternator after my car died while I was making a left turn. During the procedure, I noticed my drive belt was cracked so I bought a new one and put it on as well. After I was done, I took it for a test run and I heard a very very loud shrill squealing noise as I accelerated. I decided to tighten the drive belt tensioner some more but the noise still follows after another test run. I followed the instructions on motorvate.ca and for the drive belt, the site said that the belt should defect around 3.8-4.1mm. Wasn't quite sure what that meant so I just tightened the belt tensioner all the way. Could that have anything to do with it?

Currently, I really have no clue what to do. Is it possible the noise could be coming from the manufacturer's label attached to the new drive belt? I'd appreciate ANY help. Thanks!

 

It's definitely a loose belt. Keep tightening until it stops. But are you loosening the pulley bolt before adjusting the tension?

 

Do you mean the nut on the idler pulley? If so, then no I'm not loosening the pulley bolt. Is it necessary? After I replaced the new drive belt, I tightened the bolt and then I tightened the belt tensioner.

 

Yes, you need to loosen the nut on the pulley, and then adjust the tensioner. Tighten pulley nut when adjusted. Easiest way I found to adjust the belt is to tighten it to just past the point it doesn't squeal. This prevents having it too tight, and is easier than trying to figure how many mm's of deflection you have.

Dave

 

Thank you for the advice. I think I'll try that.

One question though. It is possible that I might have tightened the tensioner too much and that could be causing the noise? Even though the pulley nut was already tightened, I was able to tighten the tensioner a good ways even after the squeal.

 

i dont think it would have squeeled if that happened, would have just bogged down the engine. It sounds more like you set the belt loose and now its not gripping

 

Exactly what SXN said. Too tight, and you'll hear the engine bog. If the pulley nut is tight, the tensioner can't move the pulley to adjust belt tension. However, someone on here has snapped their tensioner by tightening too much with the pulley nut already tight. The FSM has the torque spec for the tensioner after you adjust the belt, somewhere around 10-14 lb/ft if I remember right (keep in mind this is AFTER you adjust belt tension and tighten pulley nut). Someone else may have their FSM handy with specs (I think on page MA-10 or so from when I changed belts).

Dave

 

like Dave said too... overtightening can create problems too, adjust a little and test it out, be nice to ur car

 

Great advice. Thank you everyone. I think I'll enjoy these forums.

 

we're here to give u advice about ur car so it runs good... if someone else knows something u dont know, why not pass on the knowledge

 

Overtightening the belt will cause the bearings in the alternator to wear out prematurely, so make sure you don't overtighten.

 

I love each and everyone one of you. I don't even need to post something new because all you have great advice for the newbies and for all my car's issues! I'll keep tightening until mine doesn't squeal....(it's so embarassing in my congested neighborhood. Some guy poked his head out of his window and said "hey lady check under your hood, you got a screwed up belt" even though my hood was already up and I was inspecting, what an idiot) ....anyways thanks for the advice everyone!!

 

If I remember right, you don't actually loosen the pulley idler bolt. There is another bolt by the tensioner bolt that you have to loosen in order for the tensioner bolt to have any effect. I could be wrong but I know I definately did not loosen my actual pulley to adjust mine.

 

also check your belt tensioner. i changed my belts and couldn't get rid of the sqeak. after i put in a new tensioner, i was able to tighten the belt correctly and the noise was gone.

 

Yeah, you are wrong.

For the ACC belt you will loosen (not remove) the pulley nut first and then use the adjustment bolt to change tension. The pulley nut only keeps the pulley at whatever vertical position it is in when tightened. Tightening or loosening with the nut still tight will strip the adjustment bolt.

*edit* You MAY be thinking of the PS which has several bolts that pivot off one another.