Hey Gang,
I have a OM617 that is knocking pretty well. I took it to the local Mercedes guys for a listen, and they think it is in the top end somewhere. They doubt that it would be the block.
It sounds to me like it is coming from around #1. I loosened each injector to see if the sound disappeared but to no avail.
I have done the diesel purge, and added some Lubro High-Test.
It is more noticeable at idle when warm, and when revved with no load, quiets a bit. Revved with load is VERY noticeable.
Does this data help, or shall I post a vid?
Later,
Nater