I bought my truck used with 27k miles on it and maintenance (Oasis) shows it has had oil changes about every 5k miles. They changed the oil before I purchased it and it had 29 miles when I bought it. The oil is dark dirty. Not clean. My 6.0 and 7.3 oil looked cleaner after a oil change than this does.

I'm thinking of changing it again just for chits and giggles. So, does your oil stay clean for a few hundred miles after the change? Should I worry.

 

Completely normal. Most of the time just a couple of minutes of run time is all it takes to turn the oil black on the 6.7 trucks.

 

If the cleanliness of your oil sticks in your side like it does mine - by-pass oil filter time. I went with the Insane Diesel filter. I use Scaefhfer oil which is green. I check my oil once a month. After the 1st month it still had a green tinge to it. Insane Diesel claims you can run the same oil for a year, that I won't be doing. We'll be waiting to see what Blackstone has to say after the truck tells me to change the oil. A lot of this stuff is in the 6.7 forum including images of people's Blackstone analysis results.

 

oil has cleaner in it... going dark is normal..

some engines darken faster then others...

then there is the EPA / EGR parts.. unlike older engines.

 

I always wondered about the oil in the HPOP. I assume it fills from the oil pan pump and overflows back to the oil pan. When you change the oil it does not drain.

If this is correct, you will always have X amount of dirty filthy oil. In your new oil.

Am I close?

 

On a truck that has a HPOP, yes. The 6.7 uses a high pressure fuel pump though. The reason for dark oil so quickly in the 6.7 is the large amount of soot the engine produces.

 

I think the primary cause of the oil turning black so quickly is the EGR system.

 

Judging the condition of your oil by looking at it.... foolish. Even more so on a diesel. They can turn dark after 1 trip. Doesn't mean a thing.

 

All diesels turn the oil black quickly after an oil change. That means the detergents in the oil are doing its job.