CM870 oil sample...

[Pete1990]

So i've been losing coolant.. My coolant lose is about 1 gallon every 25-35k Miles.. I change my oil at 15k... My recent oil sample came back with Higher numbers.... I had a shop pressure test my system we found the coolant filter was leaking. Replaced that then the system held Pressure just fine.. Where should i be looking next? This is getting old and i don't wanna keep spending money just to have a shop say sorry we don't know just run it....
This is on a 07 CM870 with welded EGR cooler and delete.. Miles on engine are almost 900k now.....

[Nilao]

Oil cooler perhaps? Fuel dilution is going up as well so maybe an injector cup is leaking. Couple areas to look.

[Pete1990]

I did have some idle time on this one. See i thought Injector cups too.. BUT i was told they would of gotten way worse by now.. But for the most part the numbers stayed the same until i idle then it will go up. Which makes me think its an injector cup issue.. Just because the numbers are very constant.. the high numbers(Sample 9) is the recent one and its when the system got pressure tested.
I thought oil cooler too but its about 2 years old and it would put Oil into coolant tank not the other way around.

[simon999]

If you have oil cooler issue you would see oil in coolant reservoir(oil in coolant). Your sample shows coolant in the oil. I had similar issue , it was oil cooler housing gasket( mixing oil and coolant ) but
I would drop oil pan and pressure test 20psi overnight. And then check there from coolant drops.
To check injector cups you can pull out injectors and see if any coolant found arround injectors.

[Pete1990]

Thank you ill get the shop to do this at the house when i go home. I pulled the valve cover before and didn't see any coolant. Would be nice to know what the real issue is though lol