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Engine oil in radiator!!!!!!!!

Jeepm@n

NAXJA Forum User
Location
Northern, WI
Ok looked into my radiator noticing the coolant was a bit low in the overflow tank and found engine oil in the radiator. Performed a compression test on a cold engine and found compression to be good. Help!!!! What is causing this on my 96 XJ automatic. It is definately engine oil and not tranny fluid. There is no coolant or creamy gunk in either tranny or engine oil's. The Jeep runs good ,but I will not run it at all like this. What is causing it?
 
Head gasket or crack in the head casting Be my $.02 worth. Ive seen hair line cracks only be a problem when the engines hot so a comp test or rad pressure test dosent always pan out.
 
Would one replace the water pump being there is oil in the radiator? What about your heater valve?
:bawl: :cry:
I just put the heater valve in a month ago. There is large amounts of oil in the radiator and I'm guessing heater core.
 
There is no way for the heater core to let oil into the radiator. If it's tranny fluid, then it could be an internal leak inside the radiator. Otherwise, the only other source of engine oil is either a cracked head or bad head gasket.
 
Unless there is an aftermarket engine oil cooler that interfaces with the cooling system, I believe head or headgasket is best guess.

To clean the radiator and heater core after repair, poor in a box of calgon detergent, it was the only thing thta worked on the bus fleet when we lost a cooler and contaminated the cooling system.

When trans coolers went, there would be trans fluid in the coolant AND coolant in the trans pan sump. While the engine was running the trans press was higher orcing ATF into coolant, when the engine stopped the cooling system was still pressurized as the coolant was hot and would be forced into the trans. It was all pressure differential, higher to lower created flow.

good luck,
Tom
 
Just a quick question, how are you sure its engine oil and not tranny? you never mentioned that the engine oil level is low also? is it? when pulling radiators, as soon as the ATF hits the coolant in the drain bucket, it's hard to tell if its ATF ir oil.
 
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