Annoying screech.

[Norbecke]

After I replaced the water pump this weekend I got this annoying screeching. I can't. Figure out what is wrong. I replaced the ac belt because it was trashed, I thought the main belt was fine but with the annoying screech I decided to replace it today. I noticed when it screeches the voltage will read 12 volts then when it stops it goes back up to 13.5-14 volts. Is there anything else I can do to stop this? Should I try to clean the alternator pulpy? The belt is within the proper tolerances for flexing. Could the alternator be going out? The screeching is not present all of the time. Just about 1/4-1/2 of the time. And I do smell almost a burnning rubber smell from the belts.

[IcemanBHE]

Yup...sounds like something is stopping and burning the belt.

[Norbecke]

The noise is gone completely I am guessing it was some residual coolant or oil that needed to burn off. My car is running great now, next on the list is to save up enough to so the VP gasket, osv utcg's, and vcg's and powder coast my spare vc's. But first I need to perhaps the wifes power steering system on her Ls400.

[Podmore]

Screeching will be caused by a slipping belt, as will the voltage drop as the alternator won't be running at engine speed when the belt is slipping, and also the burning rubber smell. Are you sure you adjusted the belt tensioner properly and have you checked the belt tensioner is actually providing the correct tension? Does it also screech when you turn the a/c on, or turn the steering wheel hard onto the stop? - all symptoms of a loose belt.
Other than that, yes maybe the slippage was caused by a few splashes of oil on the belt .... now burnt off.

[Norbecke]

I triple checked the tension and it stool made the noise. So I just drove it with the new belt on roughly 5 miles and it stopped. I was ready to go buy a new pulley and hydraulic tensioner.

[motion]

You may want to remove both belts (mark rotation direction) and feel the rotating elements and idlers to assess their condition. Just my .02