I had an authorized MB dealer change the oil on my 1985D Turbodiesel (238K miles) about a month ago. Since then I've driven about 1500 miles. I checked the oil and it is BLACK! What is going on? In my gasoline engine car, the oil has never gotten BLACK!!

welcome to diesel world!my 81 SD has 70k and burns nary a drop,after it's change my oil is black by the end of the driveway...
William Rogers....

I was under the impression that oil goes in and jet black printers ink comes out. That is why old diesels like to mark thier teritory every once in a while.

That's the nature of the beast.

Every diesel I ever worked on had THE blackest dang oil. I mean, if you get this stuff on your skin, it'll stick better than red lead #5. You have to wear it off .

It was even darker if you ran the engine for another five minutes after finishing an oil change .

Good diesels and Harleys have one thing in common -

if they ain't leaking a little black oil, there's something wrong.

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Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

I read some where that it's the soot that makes the oil that black. Diesel grade motor oils have additives in them to help control the soot. The newer direct injection diesels don't have this problem or at least as bad. With older diesels you can't use the darkness of the oil to determine how dirty it is.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

Oil in a diesel and Model T's have one thing in common, you can have any color you want, as long as it's black.

Have a great day,

I't normal for the oil to turn black almost instantly. It's known by several names such as soot, lamp black, but it's almost pure carbon. Very fine particles, so fine there is no menace to the engine. In fact, powdered carbon is used as a lubricant for some purposes.

I also makes it a convenient for reading the oil level on the dipstick because there's so much contrast.

BCingU, Jim

So, is the black "soot" coming out of our exhaust just harmless carbon?

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

Once when I was bringing the oil up to the full mark during a fresh oil change, I looked and couldn't believe my eyes. I could see the dipstick through the oil. Its only happened once though......


'84 300D-T 205K
'84 Volvo 244D 267K
'84 Chevette (Isusu Diesel) 155K (Sold)
'88 Eagle Coach Bus 690K

Interesting post! I too learned, the hard way, that engine oil in a diesel engine turns black immediately. After I bought my "old" 1984 300SD I had all the fluids changed, including the oil. After I picked up the car from the mechanic, an old Hungarian refugee, I went to put fuel in the car. Out of habit, I checked the oil. When I saw it was jet-black I suspected that the old Hungarian had stiffed me. I went back to his shop, all full of piss and vinegar. While I vented, he just smiled and nodded his head. Then he took me to the service bay, showed me a diesel that he had just changed the oil. The oil on the dispstick was pure honey color. He told me to get in the car, drove around for a mile or so and then, upon returning to the service shop, showed me the oil in the dipstick. It was now ink black!

Boy what a lesson that was. To make an already long story short, that mechanic and I became best friends. I admire him for his honesty and he admires me for my passion!

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Current Benzes

1989 300TE "Alice"
1990 300CE "Sam Spade"
1991 300CE "Beowulf" RIP (06.1991 - 10.10.2007)
1998 E320 "Orson"
2002 C320 Wagon "Molly Fox"

Res non semper sunt quae esse videntur

My Gallery

Not in this weather!

I was going to ask this same question in the general help section. I noticed that my 560SEL blackens the oil, although it takes longer than 1 mile. At 3000 miles, the oil looks nearly like ink. This car doesn't smoke, goes fast and is very clean inside the engine. I'm not worried, but I was just wondering if all of the gas engines do this as I see the diesels do.

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VR
1967 250SL

vrsmith, bet your engine is running a little rich ,and that the rings are a little worn probably not enough to effect performance, I
have worked on Toyotas that the oil stayed clean as new for six or more thousand miles, but they were normaly not brought up to the rpm and load that the big MB v8's are..........
William Rogers.......