If you remove your tensioner, and find lots of cracks in the rubber that you will see on the non-operating side, chances are good that it's worn out.

MB must own patents on a certain kind of rubber. Their rubber parts cost more than anything. (I know... MB is just proud of their parts, and it costs money to keep rubber parts available for our 25+ year old cars!!)

__________________
My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.