JD730

On stock trucks the oil will stay clean for a while, when you start turning them up and blowing smoke is when it gets real dark.

BlueOxD350

What kind of oil are you using? A non-detergent motor oil will stay clean much longer, because it's not pulling all that crud out of your engine. A good detergent oil - Rotella T, for example - will darken up very quickly as it cleans out the crap.
And I have to disagree about it taking a turned up diesel to dirty the oil... it's the nature of the beast - stock or tuned, it's gonna be black.

ruquik

Just thought I would say to go pick up the new DieselPower mag. It has a whole article dedicated to talking about oil used for diesels.

JD730

I ran Rotella T in all of my trucks and while the 93's where in their stock form the oil would still be amber on the stick after 2000 miles or more. Thats just my experience with these trucks.

BlueOxD350

Hmmmm..... for me, anything layin around the farm soot's it up pretty quick, from the Cummins' to the Deere's. Never had a modified Cummins to compare it to, though.

So I guess for the purpose of this discussion - no worries if your Rotella stays clean awhile - some do, some don't!


by the way JD - two thumbs up on the u/n ... our 730diesel is THE workhorse around the farm... dual's in the rear and a wide front = unstoppable!

Beamwalker

700 more and you could have got a really good one frome like suncoast

briankk

Thoughts on oil.. the reason that diesel oil turns black is that soot gets in it, no matter whether detergent or not. I 'bout have to think that there is something special about the ring pack in the older trucks that prevents the soot from getting to the crankcase, or at least delays it awhile..

My new, expensive transmission rebuild seems to freewheel in high gear, it's like there is no connection to the engine on overrun. Is this normal?