actuall, now i think it is the #2 cylinder (or is it #4) second one from the back. the sound is usually much quieter, after the engine has warmed up. sometimes it can be loud even when the engine is warm. it goes in and out sometimes.

the sound is definately more of a ticking than a knocking, but at times it can be very loud.

i havent done diesel purge yet, but im going to order some.

how do i "crack" the injection line? does that mean disconnecting it and capping it?

thanks for all of the help

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1991 300 D 2.5 Turbo, 220k
also in the family:
1981 240 D 185k
1991 350 SD 185k
2006 S 500
2005 SLK 350