If the stethoscope doesnt work, try droppng the tension on the belt and spinning all pulleys driven by it by hand to see if you can find a bad accessory bearing.

You can also fire a COLD engine up and run it w/o the belt for 30-60 seconds to confirm whether or not the noise is from an accessory device or not.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)