1977 240D. Just below the #1 (front) glowplug there is a round, recessed area with what looks to be a 3/4" bolt head. This isn't part of the engine (?) and I'm not sure what it is. The top of whatever this is is perfectly horizontal.
I've found an accumulation of really dirty oil about 1/8" deep in this recess. Tried to wipe out what I could with a paper towel but didn't seem to be removing much, as if it was coming in as quickly as I could remove it. But it isn't a deep accumulation, just 1/8" or so. At first I thought this was part of the vacuum pump until I looked at an online pic of the vacuum pump. What is this bolt for and anyone have an idea of the source of the oil? I don't think it is an accumulated spill from adding a quarts of oil over time. That oil would be relatively clean and this oil is jet black. -- If we couldn't laugh we would all go insane.
