wUnexplained coolant loss

[bmwkiller]

I just looked at a '91 Q for sale and found that it was low on coolant. A little more than a gallon low. I pulled the oil cap and it showed all the signs of a head gasket...brown milkshake. However, the oil on the dipstick looked fine, as did the inside of the valve cover (from what I could see through the oil fill hole). I smelled nothing in the cabin from a bad heater core, nothing in the exhaust, and saw no puddles on the ground or wet areas in the engine compartment. Nothing around the water pump or any of the hoses. We filled it, ran it a little, and the level dropped again. Then we refilled it with about 2 cups of fluid, ran it again and it seemed to be ok, but I didn't have more than about 5 minutes to let it run.The car seems to run smooth, indicating no water in the cylinder, but that oil cap concerns me. Currently the car is rarely driven due to timing chain guide issues, so I'm guessing it may just be condensation on the cap from sitting, and the fact that oil being thrown around in the engine doesn't actually hit the cap, but the fluid went somewhere. Is there any Q specific problem that might explain coolant loss like this? I haven't seen any threads about head gaskets, so I'm assuming it's not any more common on these cars than any other, yes?Thanks

[maxnix]

Actually, far less common.

Never heard of the milkshake phenomenon before, so you may have a serious problem.

Stress on guides is greatest at engine start-up, so don't even do that until they are replaced, along with the head gasket, evidently.

[elwesso]

actually, you *can* have that milky looking oil if the engine is only allowed to run for a short period of time. I had it on the bottom of my oil filler cap after only running the engine for like 5 mins... its simply the condensation burning off... Now if you had the same thing after 10-15mins of driving (10+ miles) then I would be concerned.......

Recheck that, and for the coolant loss its posisble one of your under plenum hoses has developed a small leak, however you should be able to smell it..... Possible that there was some air in there or something....

[bmwkiller]

actually, you *can* have that milky looking oil if the engine is only allowed to run for a short period of time.

The guy doesn't drive the car anymore, since he already got a new car to replace it. On our test drive I only took it around the block, given the timing chain guide problems. Since I'm new to the Q, I wanted to make sure I wasn't diving into some kind of common head gasket problem that everybody but me knows about. I've seen this before on cars that aren't driven much...just wanted to make sure. Thanks for all the input.