Quote Originally Posted by cwhiteboy
^ both posts above make good sense. As well, if he didn't replace the water pump, you could have just got real unlucky and had that go out, but thats doubtfull. My money is either on the new compressor or the tension being off of the belt. Try to find out exactly where the sound is coming from, or you could maybe take it to a more reputable mechanic and see what he says. I personally dislike mechanics, most of them have no idea what they are talking about, or doing. Thats why most people will tell you if you find a good mechanic, to keep him.
to add on to that the best way to find out if u can pin point it by ear it to just remove 1 belt at a time until the noise goes away.