Oil in coolant

[jpspohn]

1989 BMW 3251 E-30 4-door. Running fine but oil in coolant. Beige colored sludge appearing in coolant reservoir. However, no coolant in oil. Suspected head gasket. Pulled head. Gasket showed no sign of leakage. Had head pressure tested. Tested fine. No cracks and not warped. Prior to this, I had begun to have over-heating problems. I had to keep adding coolant, too, every 50 or 100 miles. I got a new cap for the expansion tank. No change. I couldn’t find any leaks. I asked a mechanic and he said something about possible exhaust gases doing something or other which I didn’t understand. Another mechanic said that if it had become severely overheated, the head might have temporarily warped enough to allow some oil into the water jacket. I’m at a loss. Anyone have any ideas?

[Rodeojoe]

I am not claiming to be a mechanic, but I would have the cooling system flushed. I have never heard of oil getting into the coolant without having coolant in the oil. As far as temporarily warping a head and it returning to normal with no evidence of a break in the seal, or a cracked head, I call BS. When you had the head tested did they just check the ports or the whole head for cracks? You could have a small crack that they didn't pick up on.

Joe

[AlpineSixAndSeven]

Flush the colant and do an oil change but i think the head is probably cracked... maybe they just missed it? temp. wraped head does sound like BS but who knows maybe this is a first and you got lucky?

[jpspohn]

I have to assume they did a competent pressure test on it. Anyway, since I don't know what else to do, I'm putting the head back on with a new gasket and having a professional mobile mechanic torque it down with his $400 torque wrench. Of course, if I have no further problems, I still won't know if it was something I did wrong the last time I had it apart (15,000 miles ago when I had let my cam belt go too long and it broke requiring a new set of valves).

[AlpineSixAndSeven]

ahhh.... yeah mighthave just been a leaky gasket.....