I have a 1993 dolphin v-6 4 speed auto, that is well maintained. While driving in hot weather 95 oat the temp climbed into the red. I pulled over left it running , opened the hood expecting to see steam and over flow and there was none. I could put my hand on the top of the radiator, the fan was running and the coolant level in the radiator was slightly elevated. I squirted water in to the radiator and the guage came down a little but still indicting very hot. I then drove over the summit and the engine cooled off very quickly and I continued another 150 miles in high altitude and warm conditions with no further problems. She runs great and was getting good mileage after the temp spike. I am almost convinced that the problem might be in my sensor. Anyone have this problem?