Rotating clicking noise from engine

[keithmerc220]

I have 2002 classic 220cdi auto estate.
When I press the accelerator there is a rotating click noise from the engine with gets faster as I accelerate. As soon as I stop accelerating and cruise the noise seems to stop. I was wondering if it was the turbo unit?

 

[Stratman]

Welcome to the forums.

Sadly, the news isn't good. You have described the classic symptoms of Mercedes Black Death (use the forum Search facility). The seal between one or more injectors and the cylinder head leaks and the combustion gasses escape with the noise you mentioned.

Look carefully in the injector wells and if you see a mucky black gunge in any of them the diagnosis is confirmed.

The cure is to remove the injector(s), possibly recut the seat and replace the injector using a new crush washer.

 

[StevenN]

Or it could be the Alternator Pulley?

Look to see if the serpentine belt jumps when you run the engine