i have an old 1985 Benz 190D (disel) that still runs well with over 260,000 miles...?

Question

i change oil every 5,000 miles using synthetic oil... does anyone know why the engine oil turns black juct after a few days of normal driving, even after using engine flush with each oil change?... are there any disel oil additives that will prolong oil change intervals?

Answer 1

Because the compression ratio is so high on diesel engines, a lot of compresion gets past the piston rings. This is just a fact of life for diesel engines. Don't worry about the black oil, it is normal. If you are going to change oil every 5k, I would use regular oil. Synthetic oil is designed for extended oil change intervals. Also try running biodiesel if you can find it in your area. Or even consider learning how to convert used cooking oil to biodiesel and save tons on fuel cost. I have a 1981 240D that I run on biodiesel that I make myself for 75 cents a gallon. For more info on making biodiesel go to
www.biodieselcommunity.org

Answer 2

Ignore the first answer, they obviously have never owned or even driven a diesel. I have an 84 Chevy Suburban with a 6.2 diesel engine. If you take care of them diesels will run forever. In a diesel engine, it is normal for the oil to become very black after a short time in use. The only time you need to worry is if it smells burnt. Trust me, you'll know the second you pull the dipstick if it is burnt or not. Keep taking care of your old diesel, and she'll keep taking care of you.

Answer 3

It's called carbon and since you didn't mention changing your air filter also, I would say that is a good source of muck. The way I see it, drive the car until it won't drive anymore and quit wasting time and worry on a 1985 Mercedes Deisel with that many miles on it. Plot it out to get newer transportation and sell it to a Mercedes enthusiast before it leaves you stuck. Stop beating a near dead horse.