Oil in radiator help.
 

So the other morning I walk outside and see oil on the ground underneath my 96 12v. Night before I went on a little drive just a cruise no right foot action and the pickup was running cool as usual 160degrees and oil pressure was normal at 40psi. Further inspection my recovery tank is full of straight engine oil. No water, no coolant clean engine oil as is the radiator. I'm hoping my oil cooler went out and not the head gasket. I have had quite a passed with this pickup about 6 years ago I changed the whole engine. block is completely flat, brand new head check completely flat and I put in a multi layered metal head gasket with arp studs. I have a killer B turbo which is waste gated at 43psi and the truck doesnt ever get over 30psi of boost. My passed experience with headgaskets is oil and coolant mix into a grey milkshake or it drink water a lot. But never seen just straight clean oil in radiator and recovery tank. Hoping someone else has dealt with this new to me problem on a 12v.

You touched on the possibilities.

Oil cooler
headgasket
cracked block

i have experienced all all of these at different times.

You’ll just have to start testing to find out.

If you pull the oil cooler, make sure to have new gaskets in hand. I’ve gotten away with reusing gaskets. But I do not recommend it.

Crawler is right, but the question I have is, where has all your coolant gone? Is it now in your crank case?

or burned out the exhaust, or pushed out the overflow.