Why is my oil black?

[Rawze]

(10-08-2019 )Brock Wrote:  Yours is a bigger cpl engine isnt it? A factory 525? Is the programming set conservatively with the timing for a higher cpl engine? Even though your hp is set lower.....

Any chance this is your issue? A demandated isx wont necessarily clean up the oil without pushing the timing?

its a delicate balancing act. Always reliability and longevity vs. higher efficiency. They contradict each other.

There is such a thing as "too clean" of oil in an engine.
There is also such a thing as "Too efficient" for any given HP and torque too.

push those boundaries too far and a severely shortened engine life will result. Seen a lot of guys try to make a 1850 or 2050 engine (500+ hp and up) push high timing advance, trying to cheat that extra bit of fuel mileage, only to end up with a fretted liner or cracked piston.


Mine used to have clean lt-brown coloured oil for 20k+ miles at a time for it being set at 435HP, 1650 trq most of its first million miles. - was not so good for the components, but I got away with it for 950k miles because torque was low and I did not drive it hard.

It has since been re-programmed to where the oil starts to get a bit dark at about 10-15k miles or so, seems to be the optimum for me anyways, and 20k you can barely see the stick under it (though I don't let it go that long very often). Power is now set to 1720ft-lbs/ 450hp though too, so I had to back it off the efficiency a bit to keep it safe.

Waterloo's truck is a big tier engine. Bigger bowl piston, bigger injectors made for larger fuel flow and different angle, different cam for more air flow .. all add up to lower compression and a bit less fuel burn efficiency. Combine that with bigger turbo vs mine as well, and that is less efficient overall too. - Still, it is impressive what fuel mileage he is squeezing out of that thing because he is driving it right and HP/torque is turned down. it is not surprising that his oil does not stay quite as clean as a mid-tiere truck will.

It can most likely be tuned so that oil runs slightly cleaner, but at what cost to the components?. - he is getting good fuel mileage out of it,.. best leave it in its safe zone, especially him having a rocky history with it in its past. Last thing someone needs is more problems simply because they want to see the oil a bit cleaner, or those last few tenths fuel mileage.