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Building in a Catch Can/Oil Separator to 300SD OM617

Started by mummyjohn, 15 September 2022, 02:29 PM


This 1979 car has the crankcase vent hose that comes off the top of the engine and is routed into the U-tube connecting the air cleaner to the turbo intake; that hose is completely melted off so it's basically a draft tube now, coating everything with oily mist.

NOW, I understand that some cars have an oil separator inside the air cleaner (and the crankcase vent tube connects directly to the top of the air filter), and that condensed, separated oil returns to the crankcase via a metal tube under the air cleaner.  At some point the engine was replaced, and so mine has this tube.  However the air cleaner is the "regular" style (no separator or anything inside; see image).

I'd like to make an oil separator and install it in here, my questions are these:
  • How to put a hole in the bottom of the air cleaner in the right location so that it can hook up with the tube?
  • How to form a good (appropriate) connection between the air cleaner oil exit and the tube?
  • The oil separator itself - I was thinking of filling with a baffling of brass mesh/wool, is there anything lacking in that plan?

Let me know if you guys observe anything I haven't thought of in this plan.  I once came across a guy who more or less did this, but can't find the posts at all now.  MANY thanks in advance, I'm sick of dripping oil off every low point in the chassis!
1979 300 SD  W116