View Full Version : 98 Catera coolant in oil, oil cooler?

01-03-10, 11:04 PM
So here's the problem, I have a 1998 Catera that has antifreeze in the oil. I am unsure if it is a head gasket or if it is the oil cooler.

Here are the symptoms: antifreeze in the oil, white stuff int he filler neck and on the dipstick, oil is 3 quarts overfull because of antifreeze. No bubbles out of the coolant tank and no overheating. As far as I can tell it doesn't smoke out of the exhaust. But It has been cold here so idk.

For a while I was loosing antifreeze and I could smell it but I couldn't see a leak. So I thought it was the heater thingy.

I have read that if the oil cooler goes that you will get oil in the antifreeze, but this doesn't sound exactly like that would be the problem.

If anyone has any better ideas or any thought's on what it might be would be appreciated.
thank you in advance,
Michael Knight

01-05-10, 04:37 PM
From your description it sounds like the oil cooler. It sits inside the engine block, between the cylinder heads and under the intake plenum, in a large coolant gallery. As I understand it acid in the coolant eats pinholes through the oil cooler allowing the high pressure coolant to spray into the lower pressured oil system. A coolant pressure test might indicate a leak but won't tell you exactly where it is but the oil cooler is the likeliest place.

01-05-10, 10:01 PM
I took the intake off and tomorrow I am going to get a pressure tester and i will test it out with the plugs out. I am hoping that it is just the oil cooler but I am starting to think that it is a head gasket leak between the oil and coolant ports on one of the block/head mating surface.

I hope that I figure this out before I tear to much apart.