BMW320i

I am looking at buying a 1984 Porsche 944 to fix up, the car has oil in the water but no water in the oil, I am pretty sure it is a leaky oil cooler, if it is fix will it be alright or is there damage already done? It has about 140K on it. THanks other than that it runs fine. TIM Has anyone else fixed this common problem? Is it hard to do?

__________________
1998 Lincoln Navigator
1988 BMW 320i (german) 1997 Lincoln Mark VIII
2004 Suzuki GS500F 1984 Honda V45 Sabre
1990 VW Golf II (german) 1994 Lincoln TC
Mechanic on the Army STRYKER