I've used the search function and google and haven't found anything that seems to fit the bill exactly, I have a 99' xj 4.0 auto tranny and it tends to run between 215-220F, I try to cruise on the four lane between 2500-2900rpm's but due to some of the hills around my area I have to get up to 3500-3800rpm's for brief stints which I know should be fine, the jeep will handle this all day unless I try to do it while running my a/c I know the compressor pulls down on the motor more but should this make the difference??? I plan on doing a complete cooling system flush this afternoon and replacing thermostat which I won't know results for a day or two has for I get home from work at later hours and I plan on running the flush through for the bare minimum of three hours run time, any other ideas of things I should check or be concerned with I noticed radiator has a slight tint of rust in it (not oil) and I'm hoping maybe the flush and t-stat will work.

 

All cooling system components must be in top notch condition and the system must be well maintained. Brown/rusty coolant is a sign of neglect. The a/c condenser gets hot, thus increasing the air temp passing thru the radiator, thus reducing the rads ability to shed heat. The a/c compressor and going up an incline will increase the load on the motor, thus increasing coolant temp. Don't postpone complete cooling system maintenance.......there's more to it than a flush and new stat.

 

Water pump vanes might be eaten away too.

 

This is a recent purchase and not a daily driver so I have plenty of time for the maintence, I'm thinking the water pump may be a issue too, I also don't believe the radiator is oem, I'll know more this afternoon worst case scenario is replacing entire system which beats running hot and cracking the head

 

Consider hood louvres such as LeBarons or other aftermarket types. After putting mine on I rarely go over the 210 mark on my temp guage. Best $50.00 investment I made and you can do it yourself. They allow the heat to leave your engine compartment.