I find that if I continually run the car at 65-70 I have little to no oil consumption. But if I run the car at 80, for an extended period of time (30 minutes) I noticed a bit of oil consumption when I check the dipstick.

You guys find increased oil consumption when you drive fast?

The car never burned a drop when I drove slower.

First of all, let me advise that 70 is fast enough.

Do you notice any blue smoke behind you at faster speeds? How about an increase in drips on the ground when parking after a higher speed run?

I'm thinking the increased crankcase pressures at higher speed may be enough to start blowing out more oil from a seal.

So the question becomes one of whether you are burning or leaking oil. Then comes the thought about whether to fix it or live with it.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

I am definitely not leaking it at all. And only certain oils. I neer burn a drop of 10W30 Ursa, but its too light of an oil for normal use.

70 is not fast enough!!

240D's are known to drink some oil at high RPM's.. I have read so much about it I would consider it "normal".

Mine will easily eat a quart of oil every 500 miles or so at 80mph.

Len
'83 240D 335,500 miles

I've experienced a similar phenomenon last April during a brisk jaunt to Corpus Christi and I think it is oil blowby making it's way into the intake via the breather.

South of San Antonio there is a significant stretch of IH37 that permits extended high speed running. For several days after that 90 minutes or so of 85+ mph, I was seeing a lot of blue smoke at start up. Heres a link to that thread: New blue smoke at start-up

The smoke has not reappeared since then.

My theory is that extendend high speed operations managed to pump a lot of oil into the separator...enough that some of it was making it's way into the intake tract and not back to the crankcase after shutdown.

Maybe this is what is happening to you too.

Regards,

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Never a dull moment at Berry Hill Farm.

Mine does the same thing. Stay under 60-65 and it uses almost no oil. Take a trip down the interstate driving above 70 and I see oil consumption. I believe the oil separator gets overwhelmed and oil is blown into the intake???

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1976 240D
1987 560SL
2007 E320 Bluetec
1998 C280 (now son’s car)
1982 240D Manual - Sold

Folks,

Not sure it applies... but similiar symptoms. I have a 96 Ford Conversion van, 5.8L V8. 110K miles, never burns a drop of oil in normal use. In two recent trips to Florida (from NC), with extended 80-90 mph speeds and heavily loaded I used about 1/2 quart of oil in my usual 3000 mile oil change cycle. In each case the next oil changes went the 3000 miles and no oil burned. I am using Castrol GTX 20w-50 weight oil. The van has a 3:55 rear end gear so it spins pretty quick even with the overdrive. I guess this may just be due to the extended time at high rpms / load.

Chuck

I drove the car to Boston yesterday...high speed..just to see how it'd work out.

Oil check beforehand reveals that oil is halfway up the dipstick.

Oil afterwards reveals about 3 ticks above the "low" line on the dipstick. And there is no noticeable smoke either.

Next change I am tempted to either change to Ursa 15W-40 (the 10W-30 never burned) or the Mobil 1 15W-50 Red Cap synthetic. I want to try synthetic.

Get Mobil Delvac 1. It's Mobil 1 for diesels.. the regular stuff does not have the soot control properties our diesels require.

When did you check the dipstick? My 240D runs at 75-80 mph most of the time. If not I get ran over. It may consume a quart or so every 1K miles. No oil seperator or EGR on the early 123 model 240D's. Crankacase straight to air filter assembly. I'm using Delvac1. I check the dipstick in the morning after the car has set for the night.

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Fred Johnson
1977 240D
1983 300SD

isn't that an oxymoron kinda'? A 240D and 80mph?

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Frank
84 500SEL EURO 101K ( JUST LIKE MY 1ST WIFE. GLAD TO GET RID OF HER! )
85 300D 310K (sold)
90 350SDL 184K sold
83 300D 118K (sold)
88 300E 153k (sold)
93 400E 105K (sold)

I have an 83, does have a separator, and I put in about half a quart to filll it up.

You will like synthetic.... swithed over 2 months ago on strength of recommendation at this board.

Improves performance, and less oil consumption too.... from 1,200 miles per quart - up to 1,500 in my case...... always driving at higher rpms, never using 3rd below 30mph and 4th never sees anything below 50... upshifting on the hashmarks..... am constantly grabbing and dropping gears at overlap range of say, 30-40mph and 50-60mph.

My theory is that diesels 'settle' at whatever engine speeds they are mostly driven....... Have also noted increased oil consuption in hotter weather, along with increased engine temperature and lower fuel mileage.

The 240 seems extemely sensitive at accomodating driver's habits and its easy to 'feel' where the engine runs best...... In my opinion, the most endearing MB ever built - clearly having the most human characteristics.

Can anybody say why burning a little oil is bad thing??

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'80 300SD/ w116
'79 240D 4-spd
'71 750cc Guzzi

previously owned:

'83 240D 4-spd
'77 280SEL 4-spd
'74 280/8
'72 250/8
'65 220Sb 4-spd
'63 220Sb 4-spd
'63 190c 4-spd
'61 220Sb 4-spd
'60 190b 4-spd

I can see where 80 mph in a 240D would be an oxymoron in some areas of the country. I live where the expressways are flat and straight, and with patience and a heavy right foot 80 mph can be reached and maintained. I'm used to the din but passengers are sometimes concerned the engine is going to fly out of the car.

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Fred Johnson
1977 240D
1983 300SD