Ive got a 1966 Allis chalmers m100b grader. I've owned and used it almost 30 years. Just discovered I'm leaking engine oil into my coolant--lots of it, say a pint of oil after a 2 hour run. I thought it was the oil cooler, but. Unfortunately, no. What's next most likely culprit?
Liner cavitation. Sorry for your loss.
I read up on cylinder cavitation. Dang. And, yes, my engine has wet liners. My situation is lots of oil in my coolant so I don't understand how a bad sleeve would allow much oil to travel from inside the cylinder to inside the coolant. Please explain. Also, short of a tear down, I'm wondering how to diagnose this. I suppose a leak down test could...but if I have bad rings I'd end up with the same results.
Thinking about more, there may be a leaking cylinder head core plug or a head gasket leak between an oil gallery and the cooling system. Is it possible to remove the oil pan? You could pressurize the cooling system with the pan off to try and find the leak.
You may be on to something, and when I've got some time I'm going to dig into this. I have noticed evidence if oil leaking at the back if the head and coming down around the back corner of the exhaust manifold, so something is going on there. I still don't get how so much leaking oil can end up in the coolant!
59 year old engine, originally built with machining practices and gasket/sealing material designed over half a century ago. Not knowing if any type of coolant additives were ever used. Just corrosion from age alone in area of gasket, block & head mating areas is highly probable. Depending on gasket material type, with X amount of heat cycles on old engines gaskets can deteriorate and allow coolant/oil in to seep. Remember the oil is under a much higher psi.
Yep, all good points. I'll do some more poking around but it's probably going to come to me pulling the heads and hopefully can just get by with new head gaskets. Best price I could find was 275 bucks...but, then again I'm just grateful that I can still source them!
Good news update...it is my oil cooler, after all! I was getting ready to pull the heads and I gavea look at the oil cooler and thought, hmmnn, I didn't really test it with much air pressure so I rigged up a way to put 30 lbs of air to the oil side and put water in the coolant side and it blows bubbles like an aquarium bubbler. A much easier fix, for sure.
Thanks for the update.
Time for a large dose of Cascade dish soap in the cooling system when you get it all back together. Cleans better than any proprietary "cooling system cleaner".