On my 96 850 Turbo, noticed some light brown flakes in the expansion tank a month ago and scheduled a coolant flush. Yesterday was the day and (crap!) saw oil in the expansion reservoir. Went underneath to drain the radiator, pulled the lower hose off, and nothing came out (zero, zip, zilch, nada). When checked, no oil on the dipstick, either. The car was on the driveway for a week or so, nothing dripping on the ground.

No white smoke out of the exhaust when running, and the temp gauge goes to normal and stays there (when I was driving it to the repair shop, BTW).

What could this be? Car runs smoothly, so I don't think it's a head gasket. The oil and coolant mix makes me think the oil cooler line ruptured in the radiator, but not having any coolant in the radiator adds something else.

What does the collective wisdom think this could be?

 

so there was no oil OR coolant in the car?

 

The dipstick was clean and nothing came out of the bottom of the radiator. I put four quarts in before driving it to the shop. The expansion reservoir was full (of sludge). I feel like Leslie Neilsen in Airplane: I picked a bad time to start doing my own maintenance on cars! Luckily, my other cars are OK on fluid level and colors.