feets

Do any of you guys have oil that stays clean for more than 30 seconds? If so, what's your secret?

oliver foster

Dead stock motors have the oil stay clean looking for longer.
Turned up pumps on these motors make the oil turn black very quickly.

feets

I put a bit of a turn on the pump but that's it. It'll put out a bit of a haze but does not smoke heavily under WOT.

jimbo486

Any diesel's oil won't stay clean for long. There is still some amount of combustion gasses that find their way passed the piston rings.

thrashingcows

My 93 motor stays pretty clean with almost all stock IP settings. Can go 3-4K miles before it really starts to even turn a chocolate brown.

My old 89 motor would turn the oil black in about a 1000 miles.

Rickcher

Anybody use synthetic? It stays clean in my gas engines but I've never tried it in the diesels.

loudhornsrule

Mine is like Tcows Stays clean 3-4000 miles then might go black. Not turned up and Rotella oil

sdseva

mine pretty much goes black right away.

MrFusion

Mine's been in there a year and looks like new.

Only put about 5 miles on her tho!

The oil in the 1995 CTD I had got filthy looking pretty quick.

I did a fair amount of research on oil for the CTD a while back. Lots of anecdotal evidence. Not a whole lot of physical or empirical evidence. One of the things that I found was that, due to the govt mandated ULSD, diesel engine oil has been reformulated because current diesel fuel is less "dirty". I can't recall the exact chain of research but its out there.
I am a dyed in the wool Pennzoil fan due to empirical evidence. I saw the inside of 70k-80k 440 motors that were run exclusively on Pennzoil and were SUPER clean. You could still see the paint on the heads under the valve covers. Pennzoil 15W40 is a bit hard to come by around here.
I ran Rotella in my 95 CTD and was generally happy with it however my current research seemed to indicate that the new Rotella is not so well formulated for the Cummins 12V. It did indicate that Valvoline Blue was well formulated for the 12V Cummins. Valvoline Blue is recommended by Cummins and meets all of their specs. Seems decent but I have no long term experience with it.

Jim Lane

About 10 minuets.
It is the soot from the combustion process,

Your compression ratio 17.5:1 is almost double that of a gas engine.

The nice thing about choosing oil for a Detroit Diesel is it is never in the engine long enough to get black

kensmachine

if you want to keep your oil clean put an oil centrifuge on it. At one time I worked for a place that sold and serviced spinner II centrifuges. Spinner IIŽ Products : High-efficiency lube oil filtration for heavy-duty diesel engines. they do work but are not cheap. Some very large engines this is all the use for a lube oil filter. there are copies made in china at about 1/3 the price but a neighbour bought 2 and I had to make bearings for both of them. WVO Centrifuge | PA Biodiesel Supply

jimbo486

If it ain't leakin', it's empty.

gyman98

My old skidsteer had a 4bt cummins in it and had 10,400hrs on it when I sold it. I would change oil about every 200hrs and it was always honey coloured.

peckens

My 03 would stay clean between changes 6k with T6. My 93 is black as soon as I start the engine, again T6. Trying seafoam in the oil for the last 500 miles of my oil change to see if that helps

Jim Lane

The old GMC transit coaches I used to work on would slobber out 5 gallons of Delo per 10 hour shift, they had 6-71 Detroit's with over one million miles on them.