working with 1990 eddie abuer bronco 5.8 auto

I replaced the whole belt tensioner assembly last month along with a new serpentine belt because the old one was squeaking and why not have the insurance of a new one. now it squeaks again!! Thought it may be the alternator but it sure sounds like the tensioner wheel. I put a little oil on it and it stopped for a minute. Could it be bad out of the box? How do I try to isolate where the noise is coming from??

 

Try a little bit of PB blaster on the belt and let it run for a little bit. Usually new belts will squeak a little. Just try to listen carefully to every pulley and see if any of them have play in them. Also check your power steering fluid.

 

One of the tricks the techs at the shop i work at do is they take a piece of rubber hose for say, a gas line or something and hole one end in their ear and the other at the pulley, like a makeshift stethoscope. Another trick a friend used on his camaro that had a belt chirp was a cleaning powder called Comet and he would dust it on while it ran it stopped it for a few days but always cam back. Another thing is to clean all the pulley surfaces and the belt ribs. Thats about all i can think of, It isn't unheard of to get a bad part so that still could be very possible.

 

Don't use any light lube (oil, pb blaster, wd-40, etc...) on a pulley EVER, pulleys have bearings, which should be packed with grease, if you use any oil you could actually dissolve the grease, leaving the bearing without lube very soon.

 

You know Encho i wonder if that's what happened to my moms chevy van... The Idler Pulley snapped off not only leaving the bolt in the bracket but also cracking the threaded hole case i ended up buying one through my work and now i am just waiting on it to arrive in the parts dept.

 

It could be, grease is a permanent lube (of sorts, it does wear off... very slowly), that's why you should avoid getting your pulleys wet, and oil is even worse, the effect is immediate.

 

It's possible the new tensioner didn't have any grease in it.

I have seen actual "belt dressing" but it isnt much more then wd40. It'll quiet for awhile then come right back.

 

guess what? I JUST dealt with this, it was hell. For starters, keep WD40 and grease and PB and oil away from all of your pulleys, it will mess up the bearings, mess up your belt, etc.

I had a squeaky belt system, at first I replaced my smog pump.. it was still there but the smog pump said it would make noise for a while, eventually it went away, I thought it was over.
It came back one day while driving around and got worse, I repacked my alternator bearings and... it was still there. Replaced the belt and it went away for a few minutes but came back. Replaced the tensioner and it was still there.

I got so sick of working on it, I just let it make the noise waiting for something to break so I knew what was causing it. Eventually, it went away and stayed away.

This passed week I thought my tensioner was making a grinding sound, it ended up being my alternator bearings but since I had the replacement tensioner I put it on in place of my old replacement just to have a newer part. Well, put my belt back on like 15 minutes ago and it is screeching like crazy. I think what happens is the tensioners, like the smog pump, have to be 'worn in'. It doesn't make any sense, maybe the bearings are built a bit too big and have to wear in? I don't know.. but it did go away, it is the EXACT same noise as it was before, so I'm going to assume it will go away again.

I regret not keeping the old one though, it took a while for it to quiet down.


Belt system noise , Bronco 351w, Saginaw Pump ? - YouTube

is this similar to the sound? This was after a while of fighting it, after the new tensioner (the one I just replaced 15 minutes ago), the one I just put on now is much louder but the noise is similar.

 

O wow. I just did my Sag swap, Im glad mine doesn't sound like that. I was looking into a new tensioner too....

 

I'm not sure if mine is the tensioner now.. i'm scared to drive it

 

Well I know Dayco currently has a rebate now if you buy a belt and tensioner together

 

I did have my belt off of the truck for a week in the freezing cold, maybe it just needs to .. reset or something?
I use the same belt you do, that Dayco Poly-Rib, it's a great belt.. grr, it might just be my alternator being noisy now. I hate this, it has definitely been the biggest headache I've had with the BRonco and I have done everything. I feel for the OP! I really do.

Either way, to the OP, I know I'm doubting myself now but it really might just need worn in? I tried everything I could to find the source of the noise.. one way if you can manage, put an impact wrench on the end of some pulleys to see if they make noise, it's the only thing I can think of. I know all of mine were silent with the belt off, they sometimes just don't make sound unless there is some pressure on it.

Could also be the new tensioner causing one of your accessories to be noisy by creating too much force on it, if the bearing is worn or something? I don't know

 

I have had tensioners go out and the replacement never makes noise doesnt have to break in. The belt noise i chased through the whole system was the air pump

 

I solved this problem on my 1994 E350 5.8 by using the 1/2 inch longer belt listed in the parts book parts guys gave me the shorter of the 2 listed. That was after 2 alternators, 1 tensioner and smog pump. Longer belt went on easy and no noise.

 

My noise came from the rear bearing of my alternator, you can have that replaced.