I'm with Bob. Seems like our English brother (crotchrocket) had a similar sound. Ended up being an idler pully with bad bearings or something along those lines.
Fingers crossed for you man.
It fixed mine!
http://vehicross.info/forums/showthr...ight=tensioner
SilverBullet75
Formerly: '01 Ebony VXSTLTH
Now: '08 Saab 9-7x Aero 6.0L