Oil turns dark fast! - PeachParts Mercedes-Benz Forum

IZELJIC · #1 03-09-2003, 01:50 PM

I just did an oil change in my 1985 300TD Wagon and I noticed that the oil turns dark within a few miles of driving. The technician assured me that in diesel engines the occurence is normal and he sees it all the time. He suggested the engine flush liquid which apparently cleans junk in the engine (done when the old oil is drained and before new oil is poured in). Please tell me that he is right. What would cause this to happen? I thought that oil changes color over time but in my 260E W124 that happens over 4000-5000 miles from the oil change and the oil still remains lighter color then.

P.S. It was -10 this morning with -30 wind chill and after two glow cycles and not being pluged in she started on me the first try!!!

Igor Zeljic, Minneapolis.

Mike Richards · #2 03-09-2003, 02:10 PM

You may get an answer on this forum; however, there is a diesel forum here too. Maybe you should post there as well.

Joe Blowe · #3 03-09-2003, 02:23 PM

Igor Zeljic:

In addition to checking out the Diesel Forum, you really ought to familiarize yourself with the search function. Most of your recently asked question have been discussed at length.

For example, Black Oil?

#4 03-09-2003, 02:25 PM

Yes, that is absolutely normal in a gas engine. In fact, if it is brown when you first change it, then the engine is relatively clean and the oil changes are being kept up with.

The black that you are seeing is soot. If you will use one of the Universal grade oils that is designed for over the road diesel trucks, there are additives to help deal with the soot. These are oils such as; Chevron Delo 400, Shell Rotella T and Mobil Delvac.

Good luck,

IZELJIC · #5 03-09-2003, 02:41 PM

Thanks for the hint on the search, it really helps me understand the diesels a lot better.