Toyota Repair: Camry makes a funny sound, power steering rack, power steering fluid

Question
My car is a 2001 Toyota Camry CE, 2.2.  It presently has 116000 miles.  The problem:  There is a low grinding/buzzing sound that comes from the engine primarily between the rpm of 1800 to 2200.  Before or after, it goes away and it doesn't matter whether I am accelerating or de-accelerating.  The sound seems to be slightly more prominent on cold starts.  I've listen to the engine under the hood and it sounds like it's coming from the area under the alternator.  It has a new alternator, water pump, belts and timing belt.  I disconected the alt belt and the sound remained.  The sounds was there before and after these parts were replaced.  It hasn't gotten worse or better.  Other than the sound the car runs great and there seem to be no drivability problems but the sound is driving me crazy.  One Mechanic said he couldn't figure out what it is and another who listen to it said it was vibration from the timing belt cover which I really don't believe.

What do you think?

Thanks,

Ron Tullos

Answer
Check the power steering fluid, is it low? If so there may be a leak in the system and the noise may be coming from the power steering pump, there may be a leak at the pump or the power steering rack seals, this is what it sounds like to me, try disconnecting the power steering pump belt and see if the noise goes away.