symptoms:

intermittent very bad rattling-knocking at front of the engine.

intermittent loss of belt driven accessories.

the car got hot on me on the way home and the belt is still on.

luckly my father in law was able to flat be it home. I am speaking of my 1990 300D which to this piont has never failed me. I have owned this car for a year put at about 20k miles on it with no real trouble till now.