RPM WS6

iTrader: (3)

Just to add some additional information, there was a revised alternator bracket released by GM for the '98 to mid-'00 cars to help with this concern (I believe the pulley mounting location is moved by 3mm with this updated piece). The revised bracket also requires a different pulley.

I don't have the TSB or part numbers handy at the moment, but it should be searchable under "revised alternator bracket" or something like this.

wssix99

iTrader: (5)

We think that your pulley's are likely the problem and not necessarily the tensioner. (We do not believe that business about the belt slipping is true.)

As the engine (and the grease in the pulleys) heats up, that noise may be going away.

We are saying that you should replace all of the pulleys on each belt at the same time. Suppose the misunderstanding about belt slipping is taken off the table and the pulley on the tensioner is the one squeaking... The car is old and it's only a matter of time until another one of the pulleys goes.

LS1121

iTrader: (17)

please watch this video. I did and bought a Gates. At 2:50 in the video is the informative part.

wssix99

iTrader: (5)

This seems consistent with what the "mechanic" is calling out, but the OP's symptoms don't appear to be fitting with the scenario as they go away when the engine warms up.