Big problem, oil in coolant

[IDIJunkie]

Hey guys, I've got a big problem! The other day when I shut the truck off I heard a funny sound, it was air bubbles comming out of the radiator, so I pulled the cap off and there was about 1 inch of oil in the radiator. It didn't appear to have any coolant in the oil, the oil is black and thick yet. I was really working the truck pulling a trailer, total weight 28000 pounds about 30 miles. The max temps were, water-210, egt-1050, and boost-10 psi. The truck runs fine, pulls fine, and starts fine. The exhaust has no abnormal smoke. It has 140,000 miles on it and new oil cooler orings were installed 4000 miles ago. I will try to get the compression numbers today to see whats going on. Anything that I should check first?

 

[tractorman86]

i'd bet on head gaskets... sorry man

 

[hesutton]

Bad - Oil cooler has leaking oil rings or a bad core.

Worse - Head gasket.

Worst- Cavitation.

Heath

 

[Agnem]

Do you see air bubbles when it is running with the radiator cap off? Oil in the coolant could just be our pesky friend the oil cooler. Compression gasses in the coolant however...

 

[subway]

compression test and coolent pressure test should help you narrow it down quick. sorry about the bad news.

 

[oldmisterbill]

I,d bet most likley the oil cooler since there is no pressurized oil passages in the head to leak through a head gasket & oil pressure is higher then the radiator pressure.

 

[typ4]

I,d bet most likley the oil cooler since there is no pressurized oil passages in the head to leak through a head gasket & oil pressure is higher then the radiator pressure.

Not at idle. when really hot. I bet,

 

[Diesel JD]

Oil in the coolant is going to be the oil cooler unless you have combustion gases in the coolant as well. Usually a headgasket leak is either going to blow on the compression side and let combustion gases in or cause an external coolant leak around the block edges. Also your sig says you have Evans waterless coolant, which should mean your cooling system is 0 psi, which means your oil pressure *better* always be higher than the pressure on the cooling side. Also I seem to recall you had head studs on your build...if so, and they were correctly installed you shouldn't have blown a gasket doing what you were doing. The weight is pushing it but the way you were working the engine was not. Mostly that weight is pushing it cause its unlikely you could stop it in a panic event.

 

[IDIJunkie]

Thanks for the comments guys, I was hopeing that it was the oil cooler, and was most positive it had to be with how good it was running. Here are the compression numbers.
1-430
2-440
3-420
4-400
5-370
6-380
7-420
8-400
Anybody know why 5&6 would be that much lower? This has to be the oil cooler leaking right? I've got the coolant and the oil drained and will try to pull the cooler tomorrow.
JD the truck has the original head gaskets and bolts.

 

[IDIJunkie]

This has to be the oil cooler leaking with those compression numbers right?

 

[hesutton]

Brandon,
I think so. It's a common place to get oil into the coolant and everything else seems OK.

Heath