Chevrolet Repair: 01 Chevy Express 3500, chevy express 3500, air leak

Question
Above vehicle has a 5.7L V8, about 65000 miles.  I can hear a very subtle noise while idling which is hard to describe.  I guess best analogy would be similar to saying "ah" at the doctor's office, but a little lower than that.  I don't hear it at cruising speeds & it isn't noticeable until after the engine is warmed up.  The belt looks ok & I also replaced the idler pulley with no change. Tensioner pulley rotates smoothly.  I'm sort of leaning towards a problem with the power steering pump (although fluid is full & looks ok) or a/c compressor (a/c itself blows cold & seems to work fine).  I'm not really sure if either of these are possibilities & how to test if they could be.  Someone else told me they thought it could be an air leak, but I think that would be more of a hissing sound, but correct me if I'm wrong.  Any ideas,and is this something I can handle myself?  Any help you can give me would be appreciated.  Also there doesn't seem to be any change in noise with the a/c on or off.


Answer
Hi Austin, Two things here, the a/c compressor hub bearing and the alternator bearings. If the noise is near the a/c then that hub bearing would be the problem. You need special tools to replace this bearing. I have done a few of these and is not a bad job, the parts are the most cost.

Hope this helps

Have a Great Day                 Mark