Just bought '85 944. Temp. runs about 1/4 from bottom of temp. gauge but when I shut down coolant drains out of the expansion tank. Previous owner thought he may have overfilled tank due to it being hard to see through. Also the cooling fans are not coming on after shut down. Should both fans come on or just one? Also the oil cooler leaked and he had collant in the oil and oil in the cooling system. Can still see some oil residue in the expansion tank. He flushed the radiator 2 or 3 times and changed the oil 2 times afer removing the head and replacing the valve guides and head gasket. Is there a cleaning fluid I should run through the radiator and oil system to clean them better?

 

For the Engine if you are sure there is now no oil water cross contamination, do a couple of oil and filter changes in quick succession. For the coolant system drop the bottom hose and flush out with a hose, then refill with water and summer coolan/antifreeze.
Regards Big Bob

 

Typically oil in the coolant is a sign of a bad oil cooler. Now coolant in the oil on the other hand, is a sign of a bad headgasket.

Have you replaced the expansion tank cap yet? The spring may be weak and allowing coolant to escape under pressure.

My turbo runs a cooler auxillary fan switch, and the car runs right at the first mark. Sitting at a stop light, if the temp starts rising, the fans will kick on at the 9 o'clock mark.

You can hit your ac button on, and see if the fans come on, they should. If they do not, then spin the fans by hand (car off). If one or both does not spin freely, then the fans are probably shot.