ok i have a 94 xj 4.0 auto. when im driving along with the ac on on the highway temps will climb to the 3rd mark on the gauge. when i cut the ac its drops back down to around normal, when im sitting still idling i can have the ac on or off and its stays normal... not sure what i can do to fix it but i need to any help? i have a rad cap on the rad so thats open system right? thanks

 

is your aux fan working

 

I had the same problem and it also started heating up at random times but never overheating. I am at about 3,000 feet elevation so not sure if that matters. I just put a 180 degree thermostat and now the jeep runs much cooler only heating up to 210 occasionally on the highway with ac on or every so often around town. Aux fan works fine and can hear it kick on and off also I can tell when the main fan clutch kicks in so that shouldn't be the problem. The temp always drops back down and I did a flush. Not sure why the engine heats up randomly but it never overheats and has all the power I need. Anyone have the same issues? Jeep has 190k on it and is all stock.

 

yes both fans work ac fan and clutch fan