Three or four times now I've found my dipstick dislodged and resultant oil spray on my 97 E300. Enough oil to cause the low oil message on the dashboard once (I refilled...and then subsequently changed the oil).

It's not everyday, and I'm trying to find a pattern. The first couple times the weather was cold (5-15F) and I had done an italian tuneup on highway onramps a couple times. Today it's in the teens, and I was driving through town with no load on the engine. The telltale sign is that I can smell oil in the cabin when I'm at a stop.

The dipstick o-ring is probably getting tired and doesn't make a real tight fit when in place, but it's not loose enough to have play in it. I tried to put in a fresh O-ring, but don't have an exact match, and the closest one is too big to fit the dipstick back in the tube.

My first fear was excessive blowby, but it doesn't happen all the time. Many cold days it's been fine, and many hard accelerations it's been fine.

Is there some EGR or PCV related valve that may be sticking, thus allowing excessive crankcase pressure?

I searched the forum, but didn't find any issues similar to this.

Any guidance is appreciated. 195k on the clock.

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Mark in MA
05 MB E320CDI 402k Granite Grey Metallic
05 MB E320CDI 267k Black
05 MB E320CDI 232k White
05 MB E320CDI 209k Tectite Grey
99 Dodge 2500 Cummins 5sp 148k
62 Jeep CJ-6 120k

There have been a few threads on this topic in regard to 617's. I think at least once the situation has been resolved with a new o-ring.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I would guess that it might be a plugged PCV system. The ones on the NA cars are quite a bit more complex and subject to damage and blockage. More so than the turbo version.

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

I'm having trouble finding a good schematic of the crankcase ventilation system. My Star CD seems woefully inadequate, and the Russian diagram site didn't seem to have much either.

Anybody have a source for a NA OM606 PCV system diagram?

Thanks

Mark

__________________
Mark in MA
05 MB E320CDI 402k Granite Grey Metallic
05 MB E320CDI 267k Black
05 MB E320CDI 232k White
05 MB E320CDI 209k Tectite Grey
99 Dodge 2500 Cummins 5sp 148k
62 Jeep CJ-6 120k

trust me over time dipstick oil ring goes bad.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran