A co-worker just had his first oil change while on vacation in his 2004 Dodge Cummins. We bought our trucks about the same time. I have not had my first oil change yet. He said that the oil was very black. The crew that did the oil change said he should change it at 5000 miles due to the black color. (He was not at a dealership.) He was pulling a 28' RV and had only good things to say about the truck. Is it normal to have oil that is very black (no new oil look) on the first change? Should he change it earlier than the book says?


Just wondering!

There is nothing wrong with "black" oil in a diesel. This is normal. The oil is doing its job by keeping the soot in suspension. By working the motor hard (pulling a load) you would expect the oil to turn black at a quicker pace than if just driving around town. The new diesel motors with the Bosch Common rail fuel injection system (Cummins and DMAX) seem to keep the oil cleaner (than on older diesel engines). I had an older Mercedes passenger car diesel that used to turn the oil pure black after 500 miles. Of course, I changed it every 3000 miles.


I am not a member of the "Cummins" club, so I will let those that own one address the mileage that that motor should go between oil changes.


By the way, welcome to the forum.http://www.dieselplace.com/forum/smileys/Hug.gifEdited by: OC_DMAX

My oil was the fresh light tan color when I first got it. Or at least up untill the point I towed a small 20' tandem axel trailer with 5 tons on a 9 1/2 trip. Once I arrived at my deer lease, I checked the oil and it was pure black, but smelled clean. And it pretty much stays black and I change it every 3,000 miles.

I have changed mine 4 times in 15K miles, each time is very black, last interval was 5K, that is what I am going to change it at from now on. In the manual the change interval on my truck is 3750 miles for extreme duty and 7500 miles for normal, it has the enhanced emmisions being a MA truck.

Thanks for the info. I felt like it was normal to have black oil at change, but I read some posts where people were talking about their oil looking fresh at change intervals. I had a Chevy 6.5 Turbo Diesel (170,000 miles) and a F-350 PowerStroke (120,000 miles) and the oil was always very black at changes. I had good luck with those engines and never worried about it. I'll tell my co-worker to just get in it and drive.


Have a nice day and thanks again!!!!