My diesel overland coolant temperature is running in the red while pulling a 3000lb camper up hills and mountain passes. The dealer says it is running normally. The owners manual says that running hot could damage the engine. Chrysler says find another dealer and try again. The answers so far are unacceptable. The front edge of the red on the temperature gauge seems to be at 230 degrees. The tech says that the engine can go to 300 degrees, but there is no way to know where in the red is 300 degrees. Anyone with a suggestion or fix?