Dad's first gen always did this, he tells me not to worry about it, but it annoys me. Sometimes when I start up, the belt will give off this annoying chirp sound. It sounds like a canary caught in the fan. I checked, no birds. If I turn the air conditioner on, it stops. If I move the throttle just above idle, it (usually) stops.

Sometimes it does not chirp at all when I start up. I have noticed that it seems to chirp more loudly on cold, damp days than on dry hot ones. I have tried spraying with belt dressing, which fixes the problem for a few seconds then it comes back. It sounds like it is coming from where the A/C compressor is, but it usually seems that when I stand on the injector side and spray where the belt links to the fan that's when it stops.

Yes, i have tried replacing the belt. Both the old and new ones do it. The idle tensioner still works properly, had to use a darn breaker bar to move it.

I did run into one interesting writeup on the subject at a Ford site (of all places), anyone have any thoughts on that?

 

I had the tensioner fail. It made a horrible amount of racket because the belt was slipping over the stopped plastic wheel. Check your belt to see if it's burnt or melting. Could be a failing tensioner bearing.

 

Well, the writing and part number text is smeared, but I don't think that's what you mean by burnt. This is just annoying chirp, chirp, chirp. Its like a bird is stuck in the fan that gets smacked every couple seconds or so. Its just annoying.

 

Have you checked the tensioner pulley bearing? I've seen a few in our shop that still move freely, but the bearing is drier than a popcorn fart.

 

I recently had the same problem.

It turns out that . . . . . the tube that connects the primary compressors outlet to the secondary compressors inlet was real close to the secondary compressors outlet pipe (hehe! ) such that when the engine idles, one pipe buzzes against the other. I stuck a quarter sized piece of 1/2 inch foam rubber between the two to keep them from worrying a hole in one another. I thought being as tight a fit as it was, I didn't need to glue the rubber in place. . . . . . .

The rubber piece eventually found its way to get caught up in the serpentine belt and stick to the water pump pulley. If you've ever seen a penny that's been run over by a locomotive, that's what the rubber looked like on the pulley. Even though it was mashed flat, it was still tall enough that it made the belt run proud of the pulley surface when things came around to that point.
The pulley was beginning to rust where the belt was missing and was well polished where the belt ran true. The tensioner was bouncing rather unusually with all this.

I was most excited when I finally saw the pulley as I slipped the new belt on the new tensioner.


Check your pulley's belt surfaces for stuff.

 

Look at tensioner and see if belt is running in middle. Many time the tensioner (pivot part) wears slightly and knocks alignment off. Also make sure engine does not have excessive end play causing belt walk.

 

My truck will do this when it's wet out. I've even got a Gator back belt which isn't supposed to do this. Our CaseIH 7140 with the 8.3 Cummins chirps loudly and nothing will stop it, belt dressing, new belt....... Talk about annoying.

 

Do I have to take it off to check it and what is the proper test procedure? I did grab it and try to shake it (engine off, of course) to check for play and it seemed solid.

I did watch it while idling under the power of a strong flashlight I just got and I did notice that it seems to wobble a little bit. It reminds me of looking at the edges of the blades of a box fan when its on high.

So maybe that thing is bad. Can I rebuild it (i.e. new bearing(s)), or do I have to buy a new one?

 

HA HA, I NEVER HEARD THAT ONE BEFORE! My brother had the same thing but his did it all the time! Not just on cold mornings. Is the belt new?

 

Yeah, about 20K miles on the belt, new 6 months ago. Last one, prolly OE, broke.

 

Mine does the same thing, only chirps on cool damp mornings. Even after it's warmed up, as long as it's damp, it'll chirp. But it's worse when I first crank it.

 

You can try to wire brush the thing while its running. Its a good way to loose limbs but might work. Start it up and lay wire brush on the belt. ( dangerous )It will buff the glazed belt back to soft grippy rubber. Also belt dressing does not work on serp belts. It will plug the pulleys with crap and make the issue worse. Check the grooved pulleys for dirt / dressing build up.

 

Ah, great. Is there any way to convert this thing to normal V belts? Not only are they cheaper, they last longer AND work better.

 

i would guess that the a/c pump and pully are the cupret, mine would squeak and chip when cold, i unhooked bypassed the a/c and mine dont do that anymore

 

I had the same thing, my fix was the same as alwaysworking's. Compressor clutch was chirping. It eventually turned into a solid "scream". So I put a NON AC belt on and all is well.