my engine has been squeaking for about a year and a half now havnt been able to pin point it. had to remove the a/c compressor cause it locked up. the water pump has been changed as well as the harmonic balancer, alternator, and belt tensioner. anyone else have that problem? what did it turn out to be? drives me crazy and cant really tell exactly where its comeing from. maybe the fan clutch?

 

Try some WD40 on the idler pulley bearing, If the noise quiets then replace the pully and your good. That is where the squeak on mine was coming from.

If it's not that then there is the possibility that it is the power steering pump bearing. Though that usually would be a much lower pitch.

You can always take off the belt and start manually spinning each item one at a time until you find something that either doesn't feel or sound right.

 

I like awe's idea of removing the belt and feeling things. See if the idlers wiggle side to side, that's how I figured out my annoying squeak was the plastic pulley on the spring loaded arm.

 

have you changed the serpentine belt and check the aarow thing on the harmonic ballance for the timing to see if it touching the balencer check the alternator