Chirping sound...

[ufgators68]

After 148,000 miles, I finally had to replace the serpentine belt and idle tensioner pulley but a slight chirping sound remains around the A/C compressor. I only get the chirp when idling with the A/C running. If I run it up to 1100 - 1500 RPM, I hear nothing. If I turn off the A/C... nothing.

Any suggestions?

The OE belt still looks good... no cracks, missing ribs or dry rot. It's now in the toolbox, as a backup. The pulley... not so much. Spinning it produced a sound comparable to shaking a jar of pennies.

 

[xentris02]

it sounds like a bearring in one of your pullys are broken

 

[Irokranger93]

alternator sound like bad.made test your alternator if you hear the little bird under your hood.suggest get out serpertine belt for replace the smaller one w/ac to o/ac

 

[Ak_Ranger]

I had the same problum in my 95 Explorer, turned out to the Belt Tension pully, after a few days the berrings in the pully went out it locked up and my belt was just sliding accross the pully. The guy at the parts store was amazed my belt didnt break when I told him what I needed. Open your hood and watch your pullys and make sure they are spinning correctly.

 

[trader007]

my 99 4.0 ohv sqeals/chirps the belt in a heartbeat if something is not right. sometimes i dont even know what it is, its like it rains once or just gets wet and from then on it will chirp at idle no matter what i do. the only thing that works is change the belt (even if the belt is only a few months old). if you had a belt made in mexico, try a belt thats made in usa. i think it has to do with the pulleys building up a certain type of rubber and then once that belt wears out and you put a different compound on it you get noise... my theory anyway.

 

[Big Jim M]

Doesn't that engine have a tensenior pully and also another one with the same bearing in it? If you only swapped one of them I'd suggest swapping the other one also.
Big JIm

 

[ufgators68]

I've changed the idler pulley and the tensioner pulley and the noise is still there. I sat and tried to pinpoint it a little more and it sounds like it's coming from the tensioner itself.

Whatever it is, it's in that general vicinty. I spun the alternator by hand and didn't get any kind of noise from it.

I guess I'm going to replace the tensioner next, since it's the next in line from least expensive to most expensive.

 

[mosher41]

my 99 4.0 chirps like a flock of birds....new belt, new tensioner, checked and rechecked alignments......i have 2 other people with the same EXACT chirp.

I have a trusty can of bird repellent ( spray silicone) one small squirt between belt and A/C pulley and birds are gone for a couple weeks....also much worse in cold weather

 

[sholzy]

Years ago I had an Olds Starfire (think Chevy Monza) that chirped. Ended up one of the pulleys were slightly out of alignment because of a loose bolt. Tightened up the bolt and chirp was gone.

 

[ufgators68]

It was the tensioner. Replaced it, drove it until the engine temp got to the normal range and came home. Put it in park, with the a/c on max and it never made a noise.

Now to see if I can return the tensioner pulley I bought earlier.

 

[trader007]

my 99 4.0 chirps like a flock of birds....new belt, new tensioner, checked and rechecked alignments......i have 2 other people with the same EXACT chirp.

I have a trusty can of bird repellent ( spray silicone) one small squirt between belt and A/C pulley and birds are gone for a couple weeks....also much worse in cold weather

i had the exact same problem for years, but i finally have been able to keep it quiet for at least a year per belt now.

the trick is to have all your pulleys absolutely clean and free of dirt, oil or anything. i actually wrapped sandpaper on a long stick and pressed it on the pullys while the engine was running... not a recommended move but it worked for me. a better way would be to remove each pulley and take a wire wheel to it.

then soak and clean all the pulleys with acetone or something similar. the key is to leave no residue at all.

put a brand new belt on. drive it for at least a couple days, and if it still chirps then remove that belt, find what country it was made in, and exchange it for a new belt made from a different country. in my case, the gates branded belt i bought from orielly's turned out to be made from mexico, and it still chirped no matter how clean i got everything. i exchanged it for a belt made in usa (which happened to be the cheaper house brand belt) and it has not made a peep in over 15 months.

like i said, the key is to get everything super clean so the belt can initially wear into the metal properly. after that, try not to get it wet because even if there is plenty of tension it always seems like water or moisture is the main cause of this chirping. the silicone spray is just a mask, you really dont want to make it more slippery either... you want to make the belt grip best it can.

 

[ufgators68]

Now that I think about it, the 98 4x4 w/ 3.0 I had, had a constant chirp to it. It wasn't loud enough to be a bother though.

Ford couldn't figure it out.

 

[cedwards82133]

Weird chirping problem resolved!!! the actual chirp seemed to echo around the waterpump area,like the normal bad pulley bearing squeal. So, to start a process of elimination. The belt tensioner was replaced. Then the idler pulley replaced. Then the alternator replaced. But,before replacing the waterpump or the AC compressor. The truck was in the shop to get new ball joints. So,the mechanic was asked to track down the chirping squeal,that would usually come and go,mostly at idle and low rpm. Turns out that it was the flywheel flexplate....hmmmm. Never wouldve guessed. Ironically the tranny was replaced 3 years earlier. Probably shouldve replaced the flexplate too,Id imagine??