I recently was told by my shop to replace the fan clutch in my '86 190d 2.5 5spd. The a/c compressor is shot and was making a little noise, but not too badly. I replaced the fan clutch and while I was in there replaced the vacuum pump.

Shortly after replacing the fan clutch, I noticed a little squeal that happened any time that my foot was on the gas, but not at idle. This only occured for 15-20 minutes and then stopped.

Now, my car is making the "Birds Chirping Under the Hood" squeal, but only while the engine is slowing down to idle speed (not while driving) and only once the car is good and warmed up. It isn't present when I start up in the morning, but when I take my foot off the gas after 30 minutes on the highway, it starts up, and diminishes as the engine slows to idle speed, but is still audible at idle. If I idle for a little bit it will all but go away.

What could this be. Could a very slight pinch of the top of the fan clutch pulley (had some trouble getting the stripped bolt out when removing the fan clutch and ended up using vice grips) be making the water pump bearing squeal when the car gets warmed up? Could it be the a/c compressor bearing going out, though this wouldn't seem to jive with the quiet when cold, squealing when hot, but only at idle speed symptoms? Or something to do with the new vacuum pump?

Anybody got any ideas of where to look first?

THANKS!!