Truck Repair: egine temp., minites, w900

Question
hi cliff! I OWN A 2000 W900 KENWORTH. N14 PLUS 525E MOTOR 13OVER 355GEARS MY PROBLEM IS HIGH OIL TEMP ON HILLS OR UNDER LONG LOAD SITUATIONS WARNING LIGHT COME ON EVEN ENGINE SHUT DOWN. WITHIN MINITES OF IDILING OR GETTING OFF THE FOOTFEED ITS BACK TO NORMAL TEMP. IVE REPLACED COOLANT T-STATS; FLUSHED COOLING SYSTEM 3 TIMES; REMOVED A/C CONDENCER;AIR TO AIR & STEAMED THEM & RADIATOR STILL THE SAME & GETTING WORSE CRUISING SPEED WATER 180DEG OIL225DEG ?  

Answer
Well actually if the engine is not heating up,and depending on year model,they had a fix for that.It was a different water pump pulley & thermostat for oil cooler.The oil cooler thermostat does not START to open until 225 degrees.So your High temp light sensor might be faulty if it comes on at 225.