I bought my 02 D/A 4x4 CC 2500 with 12k miles & the oil was black. I changed with Mobil-1 Delvac synthetic which cost a fortune. After only a few short trips around town 100mi max it is pitch black. Is this normal ? My only other experience with Diesel engines is with HUMVEES IN THE ARMY & after a oil change they would turn oil black just starting them up. I am going for the 10k oil changes & changing the filter three times before the 10k is up. Any input would be appreciated.

AIR ASSAULT 18B

That's normal for diesel engines, it's just soot that is produced as a byproduct of combustion.

I think your throwing money away. If your not running in high heat, keeping the engine hot, I'd use a quality dino, like Rotella, Valvaline super blue,or such and change oil every 5-7k. Use a a good filter, Mobil 1-303, Baldwin, OEM, NAPA, ect. Would also run a couple oil analysis test to determine what the oil condidtion actually is and just how often you need to change oil. Oil manufactures like for you to use synthetic, they make mor money on it.

Like Bill Gisse said, take an oil sample and run a good dino oil (I prefer Rotella). Once the oil goes black it's hard to get it to clean up again, that soot just sticks to everything inside the engine, especiially if it's been run hot.

I use synthetics in my truck... I do haul in missouri where its about 102 outside and i got a chip just want to take better care of my car. I do however run dino in my tractor and its almost 30 years old (diesel). I dont think synthetics really matter much in diesels.

when you say dino oil are you referring to a conventional oil? and where does one take his oil to get it analyzed?

Mobil 1 Truck & SUV is essentially the same as Delvac 1 and can be purchased at WalMart for $19.99 per 5 quart container, last time I checked (about 2 months ago).

That is almost half the price of Delvac 1.

The Duramax high pressure Bosch system keeps oil a lot cleaner than the old lower pressure injection systems that have been used for years. I change oil and filter every 6500 miles or so, and the oil at change time is never totally black on the dip stick. I suspect the truck you bought had not had an oil change in quite a while, and the Delvac 1 turned black because it picked up what was left in the sump.

As the sig says, I use Baldwin filters.

when you say dino oil are you referring to a conventional oil? and where does one take his oil to get it analyzed?

Dino means regular oil. I get my oil test kits from a nearby Catapillar dealer. You can get them from from Blackstone on the internet, some Cummins shops. They are not free. You buy the kit, follow thinstructions in the kit and mail them in.Maybe some guys nearby you can tell you where to get them in your area.

Thanks for the feedback as you are right the cost of the Delvac synthetic even at the 10k oil change is brutal. Glad to see I am not alone with the black oil. I will check with my local CAT dealer for the oil analysis.