Latest sequel to "Destruction of the Squeak"...
Following advice from the technical department of a well known fan belt manufacturer, I attempted to take the glaze off the tensioner pulley with emery paper to cure the squeak in my 300Tdi which is apparently endemic in nearly all 300's.
The squeak went!
Unfortunately, 2 - 3 weeks later, The Squeak is back. I am off to try to make a device to fit into my electric drill that will make sand papering easier and (hopefully) more effective. It is difficult to do a decent job for lack of space, short of taking off the tensioner. I will report back later....again.
Whether the initial success was due to the removal of the pulley shine or small fragments of emery getting onto the belt is debatable. It seems just about anything put onto the belt will cure the squeak short term.
Derry