Oil In Coolant

I have a 1960 CJ5 with the F-head that I plow with. Yesterday, I decided to run it a little bit as it has been sitting since I last plowed with it. I checked the oil which looked normal and just slightly below the full mark. I took the radiator cap off and saw a few spots of oil floating on top. I immediately pulled all plugs and did compression test and it had 110psi across the board. I attached a similar picture showing what it looks like in my radiator. The Jeep fired right up and runs good and no noticeable smoke (white or blue) out the exhaust. I’m looking for a little direction or insight as to what I should do next. Pull the head, inspect and if ok replace head gasket? Where else can oil enter the cooling system on these motors, but not vice versa? TIA

 

Yes when oil goes in the water, it is generally the gasket and if overheating the surface of the engine basis is not flat enough, it must be checked.
But socialists will tell you more. Better to check rapidly.

 

Thank you. It definitely doesn’t overheat. Runs and operates like normal.

 

I was scratching my head on that too. If it were mine, I would blot that oil out of there and put some more miles on it and see what happens. Since coolant isn't in the oil, I don't think you can hurt anything.

 

"oil looked normal..." No chocolate milkshake in the filler tube?

I'd be inclined to drain the oil and take a close look at what you find at the bottom of the catch container. Also, small amounts of water in the oil would theoretically evaporate at operating temperatures.

 

I guess I can’t be 100% sure that it is “normal”. Pulling off the oil cap, examining inside the filler neck, and the oil on the dipstick didn’t show anything of concern. If it were a minimal amount then it probably wouldn’t be noticeable. I guess I’ll be pulling the head off .

 

I’ve had it for 11 years and have plowed with it for all 11 years with no issues to speak of. No problems known of prior to that. Oil only goes down maybe a 1/16”-1/8 on dip stick between oil changes. Coolant has remained about 1” below top of radiator since I replaced it 5 years ago, and it always remained there prior to that. I was kind of surprised the compression test didn’t show anything. All cylinders were dead on 110 psi.

 

Your right, I think I will just change the coolant and oil, and keep an eye on it for a bit. Thank you for the help.

 

Maybe someone is playing a trick by adding a few drops of oil to the radiator ??

 

I've had oil in the radiator but it was because I used a funnel with oil all over it.

 

I doubt it. We live in the middle of nowhere and Jeep is tucked away in garage out of sight. Almost wish that was the case though

 

Oil will float on water, so you could have some water at the bottom of the oil pan. I would expect it to be picked up and mixed with the oil, which would make an emulsion that's easy to spot. Did you check the oil before or after you ran the engine?

I'm surprised that no one has suggested a coolant system pressure test. Seems like an obvious test.

 

I actually just bought a combustion leak detector that I am going to try. I will try a pressure test next. Theres not much else I can do after that, besides taking the head off.

 

Oil pressure is greater than water pressure in the radiator so a radiator pressure above 17 or so would tell you something.

 

Is the exterior of the engine clean and free of oil leaks?
I found oil in radiator water on a customers car and a thermostat housing gasket replace cured it. Slight amount of oil was drawn through the area by the bolt holes on engine cool down. A quick check to see if the bolts are snug might be an indicator.
When you pressure up the system use soapy water around all gasket mating surfaces, and also remove oil filler/breather and listen for leaks.

 

Easy on pressurizing the radiator or your next post will be " Where can I buy an F-head radiator?".....