slmskrs

I just did my 30,000 mile service, including changing the oil. After I changed the oil, I drove 9 miles, and then looked at the dipstick. It was already black. Is that normal? This is my first diesel.

formerjeepguy

Yes, it gets black very quickly especially if you suck the oil out through the dipstick as many do these days. The more old oil and residue left in the engine, the quicker it will turn black.

mjhawkins2346

I've changed diesel engine oil the old fashioned way and it is still charcoal black after a few hundred miles. Send it to Blackstone Labs when you change you oil to make sure it is still protecting the engine. My GLK is gas but I've had old Mercedes diesels in years past as well as trucks. They all had oil that turns black right away after changing. It still did it's job for the many thousands of miles. They were all pan drained until fully empty too. Made no difference.

dzl_benz

Yep, that's how it is on diesels - don't matter if it's MB, BMW, VW/Audi or any other brand. Freaked me out too first time! Keep on driving!

Alex Bel

This is already discussed on other tread. It's a diesel - do not worry.

slmskrs

Thanks all. I always drain the pan when I do oil changes, so was surprised with it black again at 9 mikes, I've always changed all my cars with synthetics at 5k miles regardless of schedule, so wondering if I should do the same thing with this diesel. Or am I wasting money? Doing it only every 10k miles would be nice but that stuff sure is dirty.

formerjeepguy

It would not hurt to change the oil and filter more often if it makes you feel better.

All diesels turn the oil black very quickly so don't let the color make you think it is dirty. A better indicator is the amount of metal particles and ash in the oil, but you need to send it off for analysis to determine those levels.

Be more concerned with the quality of the fuel that you are getting. One bad tank of fuel with too high of a sulphur content will raise hell with the emissions system. Replacing a blocked DPF or having the carbon cleaned from the EGR passages is not cheap.

slmskrs

Thanks. I think I'll go ahead and put 10k on it, and then when I change it, send it in for analysis. Would be good to know how it does over 10k.