jrvandelac

i have a 1994 jeep xj 4.0l that has been running hotter than usual(between 220 and 235) and when at constant high rpms (over about 2100 rpms) it will start to creep up into the red.
ive replace the radiator, water pump, thermostat, coolant, all sensors, and hooked my electric fan to a switch.
the fan clutch and hoses look good, and my head gasket was replaced like 2 years ago.
im stuck on what do to and dont know why its doing this?
its starting to get on my nerves

Jlovekamp

check the radiator cap, if it doesnt hold presure it will allow it to over heat. also burp your system, if there is any air in the loop it creats a air lock and you will never get coolent to flow.

djb383

Have u verified coolant temp with a infrared temp gun? Seems like a lot of new cooling system parts to be actually overheating, especially this time of year.....as in maybe a false gauge reading???

The fan clutch is 1 of the 4 main cooling system components.....u cannot look at it and determine it's condition, as they slowly deteriorate with age/miles . Spendy $35 for a new 1.

Not only does the rad cap hold pressure (to raise coolant boiling point) but it allows coolant to return to the rad when the motor cools. For the most part, the system will self-burp air as long as there r no leaks, the 2-way valve in the rad cap is functioning correctly, coolant level is at the top of the rad when the motor is COLD and coolant flows to/from the bottle as the motor heats up/cools down.

jrvandelac

I know its overheating because it boils over but i feel like it might be false reading. But ive also like taken the fan clutch and made sure it was good. The only thing left to try is replace the fan shroud because the bottom is cut out. Or the rad cap