I have a 97 TJ 6 cylinder with a 5 speed, aprox 120,000 miles. I noticed when driving yesterday in Florida's spring heat that my temp gauge rose just above 210 on the freeway at 70 mph and with the AC on it went upto 235 range.

Being that the temp was always at 210 during the winter,I would guess my thermostat is ok, to be honest I havent looked to see if the jeep has a viscious clutch on the fan, do they go bad often?.... is it time to try a chemical cleaner, change the thermostat? Do I need to add an electric fan?

Open to ideas, they say it gets warmer here....
Doug