2007 Tucson V6 Whining sound when idling NOT idler pulley
 

I've been hearing a whining sound while idling lately. It's sporadic, as in some days I hear it, some days it's not there, but I only ever hear it when idling--as soon as you hit the gas it goes away, then comes back when the engine returns to idle. Also, it only ever seems to occur when the engine has been running and is warm--don't know if that's relevant or not. I brought it to a mechanic friend close to my work who had a look while I was at work. He heard the noise, and could confirm that it was not the idler pulley, or in his words "anything external". It was something buried more deeply. He concluded that it was likely the alternator or power steering pump, but didn't want to perform any expensive "guessing and checking", so to speak, by replacing the parts and finding out later whether he was right or not. Can anybody steer us in the right direction?

He could try removing the belt if possible and see if the noise is still there.

Take the belt off and spin up pulleys by hand if any are real bad you will hear it also would feel rough if its bad enough....Use a long screwdriver touch the end on the alternator and listen through the handle if its real loud that is the problem but be careful for obvious reasons...lol