'92 IDI oil cooler fixed, oil in coolant now?

[NMF250IDI]

Hello to all,

Decided to fix the leaking oil cooler on my "new to me" '92 F250 7.3 IDI 158,000 mi. Replaced all the o-rings/ gaskets and it is no longer leaking oil...Yea! However after doing this, I ran it for a while with the oil filler cap off and noticed a fairly steady stream of "steam" coming from the crank case, and also from where the dipstick tube goes into the block. After running another day or so I'm finding a gray sludge under the radiator cap. Is it likely that the coolant/oil circuits in the oil cooler are leaking internally ? I did not see any signs of corrosion on the inside or outside of the cooler body.

I can't remember if I ran it with the oil filler cap off before fixing the oil cooler, but I don't recall seeing "steam" from the crankcase. I know I did have the radiator cap off before fixing the oil cooler and did not see any "sludge". I don't see any evidence of coolant on the dipstick.

I suspect the previous owner had put in some sort of "leak stop" in the cooling system.

Could be just the gaskets leaking where the cooler headers mount to the block...or an unrelated leak elsewhere ? Any ideas on how to test for the source of the leak ?

Thanks

[FordGuy100]

My first guess would be they mixed when you replaced the o-rings. I would try a coolant flush first, and oil change. Drive it a while and see if it still does it.

[NMF250IDI]

As it turned out I had clipped one of the coolant (skinny) o-rings on the cooler tube assembly when I put it back together.

I did drive it for a bit with the leak...with pretty messy, but hopefully not disasterous results. The water boiling in my crankcase pushed a bunch of oil/water out of the dipstick tube and applied a nice protectective coat of lube on the underside of the truck. I think it also lubed up the front ends of cars behind me on the road...I wondered why people were using their windshield wipers on a nice sunny day !

I should have pressure tested the cooling system after the cooler fix, I will this time !