Clack, clack, clack only at idle?
 

1983 300D

When warmed up I'm hearing a clack, clack, clack at idle & it's rhythmic with the engine. I've adj. the valves & I have the lubro moly comming in the mail. Injectors have approx. 55K on them.

I bled out all the injector lines & seems #3 keeps getting air in it. Yet I don't have any fuel leaking or even seeping.

Any ideas where to look?

Thanks for any help in advance...

I replaced the shock on the belt tensioner. No more noise.

Hugh Sr
1984 190d (W201) 99,454

I'll take a look at that in the am. thanks for the reply

A 190D and 300D are completely different. An OM617 has tension set by bolts on the AC, alternator and power steering pumps. In the meantime, you've answered your own question

When was the last time you changed your fuel lines? Made sure all the clamps pre-lift pump are tight?

I just got the car a few weeks ago, I'll check these also.

If It's picking up air pre-lift pump, why would only #3 have air?

Thanks

I rebuilt the lift pump, checked all the fuel lines pre pump. Vented the fuel system. It's still there. Only when warm & only at an idle.

Is it normal for the om617 to have a noise like this at idle?

Mine has a slightly different tap/clack when colt and slightly raised idle than the rest of the time. Just noticed it on my father's w210 e300d yesterday... Must be an injector-related thing.