I was going over all the tractors for the winter and found that I am getting engine oil in the radiator of the 2655. I am hoping for the best and am thinking head gasket, but where else could it be coming from? This has the MinneapolisMoline 504 engine. This has the 3 separate heads.... is there any way to tell which one might be the bad one?
 Any help would be apreciated.
                 Thanks,
                      Cal