Could some one tell me what the oil separator's purpose is? Is it an emissions device or does it serve? Is it possible to do away with it? I have an 84 300 SD and I want to remove the original air filter set up and use a K&N. If I have to keep the oil separator, does someone have some experience with providing a vacuum for the oil separator and using a K&N type filter?

Thanks

Ray

RayC,

Due to the idiosyncracies of the Diesel engine's normal operation, it tends to blow a little more blow-by gas into the crankcase. The tube you have going from the top of the valve cover to the aircleaner carries these blow-by gasses and quite a bit of misted oil, to the intake manifold. The separator is supposed to use cyclonic action to drive the liquid of the mixture to the larger diameter inside the unit, and collect it so it will drain to the sump. The gasses are ingested and burned.

Do a search on K&N air filters as within the last month a member posted a lot of details of exactly what you are trying. He had the system hooked up and running, and from the photos he posted it looked like a good, solid installation. Good luck, 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)

Ray,
I did the conversion you're thinking about a couple of weeks ago and posted my results (the link is below). So far, so good, no problems yet. I changed it around a little bit and will post a new picture of the engine bay tomorrow when I have a bit more time and my camera handy.

Air Intake Mod....

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

The oil separator is exactly that: a device to separate the oil from the blowby stream and return it to the crankcase. Reduces oil consumption considerably, and works better than the tube inside the valve cover earlier models had.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!