Need a little help,I run a 540 merlin with ext oil cooler.Over winter my oil temp would run 190 at high rpms water temp wouldnt get over 100 thought my water temp guage was bad tested guage and even replaced sending unit.two trips ago oil temp was up to 250 water was the same,I replaced the water pump impeller,Last trip oil temp ran 250 the water temp ran 105.I was told you dont want your oil temp any higher then 220. Is my engine running so cold that all the heat is going into the oil? Any HELP would be great.