psfred,

That event with my 220D happened when the car had just about 35,000 miles. I was in Vermont at the time, and I drove to the nearest dealer (Woodstock, as I recall now about 27 years later) and had the diaphragm replaced. I was more of a novice at this Diesel stuff then and was sure I did not want to drive the car around billowing smoke. The oil consumption at idle was horrendous, but at normal speeds it was higher than the norm for the car in near new condition, but not so bad as to require frequent stops to add a quart.

The experience so unnerved me at the time I actually bought a spare pump diaphragm and carried it in the car for the next 200,000 miles but never needed it.

My point was, when you dump a significant quantity of wet, liquid oil into the combustion chamber, along with the appropriate amount of Diesel fuel, there is not enough air to burn that extra rich load of hydrocarbons. Since the engine oil is not being atomized to enhance combustion since it is probably never going to ignite. Which gives rise to the white smoke.

When seals leak, and eventually I got a little more daring with that 220D and did a head rebuild in my driveway and saw the evidence first hand, they allow a steady dribble of oil to run down the valve stem. In my car the intake valves got so covered with carbonized engine oil they stopped seating, and choked off the flow of air. The intake valves and surrounding area upstream of the combustion chambers was wet with tarry oil deposits. It all cleaned up well enough and went back together fine, running another 80,000 miles when I "sold" it to my Father-in-law. He used to chide me about driving a Mercedes Diesel, but he was converted. He kept the car for 3 or 4 years, and traded it in on a 1981 240D with 84,0000 miles about ten years ago. He still has that car, a manual, with around 180,000 miles on it now. It rests during the winter to keep it from rusting, and is in near new condition.

Well, all I wanted to do is point out leaking seals can cause unusual quantities of oil to be sucked into the combustion chamber, and once in there can show up in a variety of colors at the tailpipe. 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)