Pontiac Repair: Screeching Noise, shop mechanic, power steering pump

Question
What will cause a loud screeching noise coming from the belt area in a 1996 Pontiac Bonneville?  I recently had an intake manifold replaced and shortly there afterwards a loud screeching noise started.  The shop mechanic can't seem to find the cause of the problem.  I nee my car and no one seems to be able to fing the problem. Do you have any suggestions that we may be able to try.

Answer
HI Rosie, I can tell what I would do. I would take the belt a loose if the noise is there, then it is in the engine. and if is still makeing the noise then it could be a ilder pull, the alternator bearing, A/C can cause this, power steering pump. the water pump, and it also could be the belt. this is what i would check for.