For the last week or so, I've been getting this strange screeching/groaning sound from the engine area of my 1995 Volvo 850 T-5R. When I first heard the sound, it only lasted for a few seconds; now, the sound lasts for a minute or two, until the engine warms up a bit. For the music heads out there, it sounds like Sonic Youth or The Jesus and Mary Chain is playing in my engine.

The car has about 158k on it and the timing belt was changed at 135k. The temperatures here have been in the 80s and 90s, so according to what I've researched, this doesn't seem to be the air pump "ghost" that others have experienced when starting their 850s in cold weather. From what I've deduced from a Brickboard search, it could be the idler pulley, serpentine belt, idler bearing, water pump, air pump, or in fact the spirit of old man Volvo?

I recorded a 30 second clip of the sound today and uploaded it here:

http://www.youtube.com/watch?v=-9MvAjVXb7s

Any suggestions, advice, or personal experiences before I bring this in to the stealership would be greatly welcome. Thanks.