Maverick,

On my old 1975 240D the injection pump had a little red cap with "OEL" written on it. If you pulled it out, there was a little dipstick hanging there to measure the oil in the lower end of the injection pump. I am not sure if the 350SD has this feature or not, but along with the little red cap was a small tube that came up and then bent 180 degrees to point at the driveway. Well, once upon a time I was changing oil in a buddy's parent's driveway and I got done, saw this little red cap and thought I ought to check it out. So I pulled it and found the oil level above the bottom mark, but below the mid point of the span to full. So, I thought I should top it off. Well, I poured a little late '70s Mobil 1 of a near water viscosity in and checked again. Still looked a little low, so I poured some more in. After two quarts, I noticed oil building up on my sneaker as it ran down the driveway. And then I discovered that little vent/drain tube. I never got invited to work on cars at that buddy's house again.

Anyway, that car did not have any injection pump to engine oil connection. The stuff that was in there was clean as new oil. Even before I did what I did. But if the new ones do, and they have a little "U" shaped tube on the inside wall of the injection pump, you may be getting oil out of that tube. Can't go check a car since I no longer have a 350SD, but thought I would pass on the story. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)