Dave!

So I noticed that my car was making a chirping noise, very much like lower-pitched crickets. I pulled the belt and ran it and yeah, it's something off the belt. None of the pulleys are loose, but turning the alternator I can hear a somewhat rapid (but faint) "tic tic tic tic". Is this standard for the alternator or is it shot?

Edit: Tried to get a video but the chirping doesn't come out in it.

Double Edit: I have a solid pulley (apparently I'm supposed to have a clutched pulley with a manual), or did they put the clutched pulley in after 2000?

peavynation

Do you have a 6sp or Tip?

6sp cars have a free-wheeling pulley that will allow the alternator to turn faster than the engine (like a free-wheeling rear hub on a bike). That is, if you spin up the motor to 7k, and the alternator is going like heck, and then the motor spins down to a much lower RPM, the slowing belt wont bring the alternator RPM down with it, the alternator will be left to freewheel until it's pulley speed matches the belt again. Tips have a standard fixed pulley.

Could be in that alt pulley, in the alternator input bearing, an idler pulley, or even the water pump. Hmm, I guess I didn't help much.

Dave!

I've got the 6spd, but I've got a solid pulley for whatever reason.

I've hit everything with a stethoscope and it sounds like the chirping--and a faint "whirling" noise, too--is coming from the alternator and not any of the pulleys. It's just odd to me that there's no slop in any of the pulleys.

Thanks for the explanation on the alt. pulleys, knew there was a difference but not really what it was.

1999Porsche911

Did you try installing a new belt? A bad belt can make all sorts of ticks and squeals and still look good to the eye.

Dave!

I put a new belt in a few months ago. Actually I remember a slightly "off" sound right after I installed it that I just identified as an idler--I figured it was just the new belt breaking in back then.

So that faint "whirling" noise was the idler next to the alternator, though I can't say what the chirping is, so I'm just going to switch out the idlers and see what it sounds like from there. Maybe the chirping is just part of the idler noise but it does seem like it's coming from the alternator. Guess I'll find out.

Quick note: Are the idlers different between the 6pd and the tip?

Dave!

Closure: So it turns out that it was the tensioner pulley, which was surprisingly easy to replace considering what I had seen about it. Crummy thing is, thinking that it was the idler pulley, I bought one, tried it on the car, realized it wasn't the issue but since it went on the car the dealership won't accept a return.

So anyone who's interested in a brand new upper idler pulley with 2 minutes of car time, shoot me a PM.