[MBZ] Squeak on startup

[Peter Frederick]

I'm getting a funny little squeak with a cold engine on my 87 300D.  
Can't hear it inside, I only noticed because I had to run back into 
work today right after I started the car.

Sounds like a slipping belt, goes away as the engine warms up.
Is this a bad tensioner pulley?  I'd just as soon replace it now as 
wait til it breaks....


Peter