Squealing BELT - Which pulley

98 Windstar. Have been dealing with this problem on and off for 20k miles. My van eats belt like mad. Started with the first replacement, I used a Goodyear Gatorback belt; it didn't like that. Currently I have a ridiculous squeal that happen ALL the time (worse of course when driving). I know it's the belt because driping water on it shuts it up completely at all RPMs. In fact, I also know it is a pully on the ridge (not flat side of the belt) because dripping water on the flat side has no effect on the sound.

I have in those 20k miles replaced: the tensioner, idler pully, and the alternator; all of which have had no effect on the sound (worse or better). The most recent event left the tensioner riped in half; see it at: http://www.davidmbrooks.com/images/tensioner.jpg

So, what is the problem? Before you answer: This weekend I replaced the Powersteering pump (same pulley), the alternator (free underwarranty), and the idler (again). None of which had an affect on the sound. I've checked the alignment and nothing seems off. I even adjusted the alignment of the bearing in the new tensioner to have the belt ride more in the middle.

Any ideas?

I do need that stethoscope, and I'll get one today, but I'm still wondering if anyone has had this problem on their 98 Windstar.

Another thing is that it gets better (never goes away) as the belt ages. Makes me think maybe the depth of the ribs in the pully don't match the depth in a new belt?

I do need that stethoscope, and I'll get one today, but I'm still wondering if anyone has had this problem on their 98 Windstar.

Another thing is that it gets better (never goes away) as the belt ages. Makes me think maybe the depth of the ribs in the pully don't match the depth in a new belt?Try this spinktec, This happened on my 96 windstar this past summer. I found crud and oil residue buildup on my pulleys. I just cleaned the pulleys with brakecleen(small amount on a clean rag) around all the pulleys then I used a teflon non scratch pad on the pulleys to get any left over crud on them. Gave a final wipe with a clean rag reinstalled the belt presto noise gone. If that does 'nt work you'll need the stethscope. lets us no what happened.

I cleaned the pulleys with carb cleaner and a wire brush, then rinsed them with brake cleaner. It worked.

While I was doing it I could tell by the amount of rubber washing off that it would probably work. I cleaned 4 pulleys in all: power steering, tensioner (plastic), air conditioner, crank. I took the belt off and cleaned all except the crank by hand. I cleaned the crank with the engine running by laying wire brush against the pully from under the car while spraying carb cleaner on it. Sounds hairy but in fact it was quite tame.