V70 AWD oil in water help please
 

Hi all, this is my first post but not my first v70, I went to look a a v70 today the car is good all-round but it has oil in the water....
I dont mean I bit creamy but actual oil I dipped my finger into the header tank and it was thick oil.
I checked the dipstick and that was fine as was the rocker cap no signs of water in the oil.
Should I run a mile?? it only done 110k full history, starts perfectly, no clouds of white smoke to suggest head gasket,
fumes smell a tad oily, the ownwr said it would overheat after about 10 miles (but if the oil is in place of the water this would happen anyway wouldn't it)
I am very drawn to thinking the head gasket may be ok but the cooler in the rad has died. Any help please would be awesome. thank you dee