Water in oil

[RDBuck]

Friend has a 90 automatic cummins. Runs fine but puts serious water into the oil. No oil in the water. Head gasket has been changed and showed no evidence of prior leakage. When we drained cooling system and pressurized with air only we could hear air leaking into base in vincinity of below the lift pump. Anyone have experience with this problem? Porous block? Cracked block?

Another thing different is the oil filler on the valve cover and a mechanical outlet for a tach on the timing gear cover. He bought this truck used and does not know its' history.

 

[CrewCabDiesel]

Big time Bummer,

Possible crack in one of the cyc. walls. Seen similar problems with a gas V8. Hope I am wrong, but it can be fixed by sleving the offending cyc. I would have the entire block Magna Fluxed for other cracks before doing any repairs. I would also have the head checked as well, the 1989 to early 1991s had 9mm heads, and were prone to cracking.

Kyle

 

[PMedina]

I had a problem with my oil cooler leaking. The oil cooler is basically a small radiator that mounts inside the block and is cooled by coolant. When mine leaked coolant passed into the oil, but no oil passed into the coolant. Coolant into the oil is a serious problem. It starts attacking the main bearings very quickly. My problem happened over 5k miles or less and I had to replace

the main bearings. If coolant is getting into the crankcase, you may see some condensation on the underside of your oil filler cap. Some of the oil and coolant mixture turns to a brown slime. I saw evidence of this at the crankcase vent tube and the uderside of the valve covers. Oil analysis is

probably the easiest way to determine if you have this problem. They can check the oil for glycol and water. The oil cooler repair is relatively cheap, $400 for mine, compared to replacing the

main bearings. My oil cooler was actually fine, but there was a problem with one of the gaskets.



Paul