I purchased a used 1982 300SD last year and for as long as I've owned it it's required an insane amount of oil. Every time I fill up the tank it needs a good 3 to 4 quarts. A few possibilities I found online were worn piston rings or worn vacuum pump diaphragm. To check for worn piston rings I tried unscrewing the oil cap after starting to see how much blow by it had. The cap danced around but didn't come of. I'd like to check the vacuum pump diaphragm but I don't know where it is. Maybe the problem is something else altogether? The passenger side of the engine is covered in oil, but there is so much of it I can't quite tell where it is coming from. Occasionally that side of the engine smokes a little bit when I'm waiting at a stoplight. I realize it could be any number of things so I'd like to start with most likely possibilities, where would be a good place to start? thanks.

If it was leaking that much oil you would see a pretty big puddle every day when you parked it...have you noticed any cleanup crews following you around?

Is there oil coming out the tailpipe? If so you could have shot turbo bearing seal too.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Haha, no cleanup crews. It does leave a few stains though. Note that I have to actually dive the 100 miles before it uses up the 1qt of oil. If I just let it sit there for a week in the driveway the oil level doesn't change. How do I tell if oil is coming out of the tailpipe? Am I looking for a particular color of smoke?

Start with cleaning the engine so you can tell how much is being lost from leakage while running.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

if there are puddles when you stop, maybe you just need a valve cover gasket. easy to replace, then go to the car wash and clean it off so you can see if it continues to leak. or just go there first and clean it off and see where is it leaking from.

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1985 300SD
1998 Jetta TDI
Previous: lots of diesel VW's, MB's, KW's, Pete, Freightliner


Walking isn't a lost art: one must, by some means, get to the garage.

Is the air filter oil soaked? The oil/air separator tube could be disconnected from the bottom of the air cleaner. Also, the turbo drain seals could be worn out.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D

If it's the passenger side, you've probably got a problem related to the turbo, either the turbo itself, the oil feed to or drain from it.

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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

Look here first. If the tube is connected, it could be a plugged check valve at the return to the block. I cleared mine by putting some oil under pressure down the return tube.

The lines to the turbo are metal (pressure line) and a loose air cleaner mount can rub a hole that will spray out oil at a fast rate. Also a check valve on this return line.

Not much else on the passenger side.

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Charles
1983 300D, bought new, 215k+ miles, donated to Purple Hearts veterans charity but I have parts for sale: http://www.peachparts.com/shopforum/mercedes-benz-cars-sale/296386-fs-1-owner-83-mb-300d-turbo-rebuild-parts.html

You've driven it a year needing 3-4 quarts of oil per fill-up? Thats not cheap!

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Check your oil cooler lines. If the motor mounts are bad, they let the motor sag and eventually it wears a hole in the cooler lines. Ask me how I know.

Could it possibly be the rear main bearing seal? I had a 1960 MGA 1600 sports car that had a rear main bearing seal leak, and it would use just about the same amount of oil that your engine is using. When parked, there would be an oil spot underneath the car, but not enough to account for all the oil being used. It seems that the oil was dripping out while the engine was running, and when it was parked, there would just be a stain from the residual oil left on the cross members. As mentioned by other posters, the first thing to do is clean up the engine as much as possible and try to ascertain where the leak is coming from. You mentioned some smoke when stopped at a traffic light. This could be coming from oil dripping onto the exhaust manifold or lower exhaust pipes. Good luck

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96 E300d

normally high oil consumption means bad rings....but sounds more like a leak and getting oil on the exhaust....like the others said, clean, clean, clean that thing. your gonna have to get down and dirty to find that leak.

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1987 300TDT
1981 VW MKI Caddy 1.6 diesel, waiting on engine swap
1983 D-50 Power Ram 4x4 "Mitsubishi" 2.3 turbo diesel
assorted gas powered crap and motorcycles

RIP: 1984 300TDT, 1982 300TDT, 1984 190D 2.2, 1992 300D 2.5, 1987 300TDT, 1982 Maxima LD28, 1983 Maxima LD28, Isuzu C223 P'ups X3, 1983 Holiday Rambler 6.2 Banks turbo diesel, 1984 Winnebago LeSharo 2.1 TD, 1985 Allegro 6.5

Valve stem seals are cheap to install and can make a huge difference...
also, be sure you are not filling the crankcase too full .. half way between min and max is recommended by many...

Ditto the overfilling statement. Also, make sure you pull the dipstick, wipe, re-insert then check the level. If you pull it directly out it won't read correctly.

If you overfill, there is a hazard of possible runaway.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Thanks for all the tips. I did some looking around under the air filter. Turns out the drain on the bottom of the air filter wasn't sitting inside the metal tube below it. So I suspect the oil was dripping from there right onto the exhaust pipe and vaporizing. The air filter must have rattled around so much that it came out. I re-secured it and tightened some screws. I'm cautiously optimistic that this will solve most of the leak.