just bought 944. While driving, engine temp. is stable at about 1/4 up from bottom of gauge. When shut down the fans don't come on and coolant drains out of expansion tank. The guy thought he may have overfilled it with coolant as the expansion tank is hard to see through. Would this cause the overflow? Should both fans come on or just one? Also oil cooler went bad and let coolant into the oil system and oil into the coolant system. The guy removed the head, checked for cracks and reinstalled with new valve guides and head gasket. He then changed oil twice and flushed the cooling system three times. I can still see some oil residue in the expansion tank. Is there a cleaning fluid I should run through the oil and coolant systems to clean them out better?

 

Sounds like it might be just low on coolant and needs to be bled properly. You can remove the expansion tank to try and clean it out, but it is a real bugger to get all that out.

 

I filled the expansion tank with plain water, did some driving and when I shut down both fans came on and no coolant overflowed-you get lucky sometimes. As far as residue from coolant in the crankcase and oil in the cooling system, I'm just wondering if it will hurt these systems in the long run. Thanks for any info.