Hi all. Wonder if anyone has had this problem. I have a 1999 xj, 4.0l. Recently had to change the hoses on the radiator due to leaks. Since the change I have experienced radical overheating problems that come at intermittent times. I have changed the thermostat twice, the temp sensor, the water pump, flushed the radiator twice and burped the system. I do not think there is any air left in the system. Anyone have any helpfull hints out there? Oh, I did forget to mention, the operating conditions are usually with the AC on upon onset of overheating. The temp drops back to normal like a brick if I turn the AC off and occasionally have to tunr the heater on. As soon as I get back to a normal temp, I can run the AC with no problems.:confused1 Thanks for any help ou there.