I have a very annoying belt squeal in my 96 XLT. My mechanic replaced the idler pulley and the noise was gone for about a day. Out of frustration I gave the belt a shot of WD40 and the noise immediately stopped. I had my mechanic put on a new belt and that did the job for a few weeks and now the squeal has returned again. Again with a shot of WD40 the squeal stops for just a few minutes and then starts again. I was wondering if anyone else out there has had this same problem and found a solution. My mechanic doesn't have an answer, and I can't afford to replace the belt every month or so.

 

Have the same on my 92 F-150. Changed belt and idle pulley. Keeps coming back. Squirt some WD-40 into the new idle pulley & it goes away.Do not have the problem on 3 other Fords????If you figure it out let me know?

 

--Had the same on my 96 4.0. It went away if sprayed with belt dressing, but only stayed away when I replaced with a different brand belt. Of course, I can't recall the brands.

 

I've run into this also and the culprit turned out to be generously sized replacement belts that allowed the tensioner to unwind to the point where proper belt tension could not be maintained. I verified the first belt was the proper stock number from the parts store and then tried a second manufacturer. Sure enough, the second was smaller by at least 1.5-2.0 inches. Mine was most noticeable when the A/C compressor was engaged, producing a load on the system.

 

I have the same noise. I may try a new belt again. I got the van used (2 years old). Its a '94 extended, 3.0L. It squeeled from the first hot day after we bought it, with the a/c on. I assume it did this from new! I promptly replaced the belt. I don't know if it had the factory original then, I assume so being 2 years old. I did not replace it with a Ford belt either. (I don't remember what brand I got, it was in early '97). But with that new belt it was quiet for a while and then it has managed to keep that horrible noise still for all these years, with the a/c loaded. I did go underneath one day and lightly touched the side of a shiney wrench against the back of the noisy belt as it spun. I did this on the belt before it went up, over the a/c compressor (if I remember right, its been a while). The noise went away with the wrench on it. I looked at it and see the belt seems to vibrate a million times a second as it spins and slows for the loaded compressor. This seems to create the noise. Maybe wrong aswell! But as long as it makes the noise, I know the compressors working!!
I can see that the new belts we have all replaced with are quiet for a week or so, until they get broken in and soft enough to vibrate more. This is what I have managed to deduce from this problem!
But maybe I will try a new belt, finding one a little shorter as mentioned in one of the other replys. Maybe the tightness will stop the noise. We'll see.

 

Finally got round to replacing the belt. Used Motorcraft from Ford. After a few weeks it hasn't squeeled yet. Those other brands squeeled almost as soon as I installed it.

 

just in case it comes back, replace the belt tensioner that solved my squeal indefinitely.