Noise at start up?

[Beowulf]

The idler pulley and alternator have been replaced. OPDA has been removed and checked for wear. Belt has been replaced. The sound is forward of the OPDA. Happens at startup when cold. After 15 minutes stops at idle but does it with throttle. After another 15-20 minutes stops at any throttle position. It is a squeak like you would expect from a loose belt or bad pulley.

What could be causing the noise?

 

[Beowulf]

The sound is clearly on the center/left side when facing the vehicle so that eliminates the AC compressor and the power steering pump in my opinion. The fan clutch is a possibility but it has no play and feels smooth. In the mean time I am installing the OPDA.


Possibilities
Fan Clutch
Water Pump
York Compressor Clutch
Other internal engine issues such as timing chain, bearings, lifters, etc.

 

[Jim K in PA]

You say the idler pulley was replaced. What about the tensioner pulley?