I picked up a 93 Impreza 1.8 153K. It runs fine but the coolant was full of oil, 99% oil. The oil does not have coolant in it, its clean as can be.

 

Initially, I thought one of the quick lubes missed serviced. The PO said, that was not the case and the engine was using oil. They kept it full of Oil.

 

Has anyone seen this? Head Gasket? Thanks, Larry

first - i would make sure that no coolant is getting in the oil. if the previous owner added alot of water instead of coolant (which is often done since antifreeze can be quite expensive if you have to keep adding it at $5-$7 a bottle). water won't show up nearly as well in the oil as the antifreeze will.

 

i have seen headgaskets leak only oil and no antifreeze, but that has been external leakage at the rear of the head gasket. if not coolant is getting in the oil it should be head gasket and not a cracked block or something bad like that.

I picked up a 93 Impreza 1.8 153K. It runs fine but the coolant was full of oil, 99% oil. The oil does not have coolant in it, its clean as can be.

 

Initially, I thought one of the quick lubes missed serviced. The PO said, that was not the case and the engine was using oil. They kept it full of Oil.

 

Has anyone seen this? Head Gasket? Thanks, Larry

There's potential for lots of problems under this condition. In comparison to a 50% water/antifreeze mixture, oil has only a bit more than half of the specific heat capacity and only about a fifth of the thermal conductivity, in addition to being more viscous. That makes it a very poor engine coolant, so whatever the original cause of the oil in the coolant, the longer the engine was/is run this way the more likely there will be additional damage.