Did the 1st oil change today, have a question.... Anyone know what Cummins uses for assembly lube in the engine? That was THE thickest, blackest oil I've ever drained from one of my own vehicles. I'm assuming the break in lube causes that( maybe lots of moly ?). Changed at 5100 miles (I fall in the 7500 schedule), mostly highway miles(90percent) I know alot of you have acknowledged the black oil syndrome, but I didn't expect it to be so thick. Just curious.

 

Cummins engines come with Valvoline Premium Blue in their bellies. Don't know why yours would be thick. My '95 came out fairly clean at it's first 4k mile change. My '98 came out ink black at it's 4k mile change. My '01.5 came out dark but not black at it's first 5k mile change. And my '03 SO came out black but not too thick at it's first 7500mile change. If this is your first diesel, maybe you're not used to 15w-40 oil. It's pretty thick. The 5w-20 Mobil-1 I use in my Hemi is like iced tea going in and coming out.

 

I drove a PSD Ford for 9 years, so not my 1st rodeo. It wasn't so much thick as tacky, maybe, hard to describe it I guess. Not a big deal, I have no issues w/ oil pressure, noises etc., just one of those things that make you go hmmm....