I sprayed WD-40 on my belt about two weeks ago and it won't stop chirping either. I guess I got some where it doesn't belong. But the chirping stops after the engine warms up (about 10 minutes after starting). Does your chirping eventually stop until you accelerate?

WD40 on a belt is a bad idea. I would replace that belt now....new or not. The WD40 will cause it to stretch and thus wear out prematurely.

Rob.....I would try the soap on your belt as well....it stays on and actually "lubes" better than the WD40.

Mine chirps as well, its very annoying. It does stop after a while of driving though. The worst is if I dont drive it for like a week or more and then start it, it screams like hell then. I have tried everything I can think of and still wont stop....I am glad to see that it isnt just mine that does it....LOL.. I do wish though that I could get rid of it once and for all though.

WD-40, like soap, is good for checking which component is slipping (causing squeak). It actually softens the rubber and causes it to "grip" better. But it is only a temporary fix.
Another possible cause can be Antifreeze leaks. Very slippery.

Yes but, soft rubber that gets hot will stretch....soap you can just wash off unlike WD40... it penetrates the rubber and makes it wear quicker. WD40 is a type of oil and what happens is that the belt will slip even more causing extra friction and make the belt hot and softening the rubber and in turn causing it to grip better for a little while but, it is a good way to ruin a perfectly good belt.

You should not use any type of lubricant on a serpentine belt. Even the Belt Dressing spray they make is for V-belts, not serpentine belts.

I can see using soap to find a chirping/squeaking component as it will wash right off as stated.

I've also found that the Goodyear Gatorback belts are one of the quietest serpentine belts out there.

Thanks for the advice guys, even though it's a little too late for that belt. :)

Mine does this exact same thing LOL. But after I sprayed it, it got worse... :( Won't be doing that again. I was starting to think it was a pulley or some bearings had gone, but hopefully it's just a bad belt.

Already stated. $30 gator back belt. Never use lubricants! Buy the gator back, All of you! and all your chirps will go away.

Switched the alternator and the ac compressor for the hell of it cause my buddy had one laying around the shop. Noise still didnt go away, tried a different idler and tensioner as well even though there's brand new ones. The harmonic balancer isn't moving. Tried to see if it was the power sterring or water pump, but they seemed alright as well.

So today I decided to try the soap trick. I held off so long because it's a temporary fix. When I put the soap on the undridged side of the belt, it did nothing. When I put it on the ridged underside, the whistling/chirping stopped while the car was idling. There's still a noise while I'm driving, but it's very faint and much more bearable than before. So I'm convinced it has to be a belt or pulley problem, but nothing seems to be working. For now I'm just gonna hope the soap lasts a while so I don't have to throw it on every day. I'll keep everything updated. But for now I have more important things to worry about, this has been a huge headache.

Thanks for the advice frog.

You're welcome....but, the soap is there just to help identify the problem....and will wear off in a few minutes.

The only parts on the engine that are "ribbed"...yes I said it!!!
Are the P/S pulley, Alt pulley, A/C compressor pulley, Harmonic Balance pulley and maybe an idler pulley. When you applied the soap to the back side of the belt and it did nothing that tells me that all the smooth pulley's are ok...ie water pump, tensioner etc...

Now, when you placed it on the grooved side of the belt that tells me that it is one of the grooved pulley's and you have already changed at least 3 of them A/C, Alt, Idler (if it is grooved), now on the P/S pulley how much if any of the shaft is sticking out that the pulley mounts to??

Oh, and for the record I am not running a gator back belt and I have no chirping.....(knock on wood) but, who knows I might in the future...I am running a gates belt from O'reilly.