94 jeep cherokee sport 4.0 runs hot going down the road

first I would try checking your coolant levels. If they are full check to see if the opening to the engine for the coolant isn't clogged. If it is not you may want to try getting a different temperature controller. Sometimes car companies use to small of injectors.

I have checked all that its all good. Just put a new thurmastat in it and it still dose it. Someone told me it is eather the water pump or its the radiader

You might want to look at your radiator while it is running to make sure it isn't leaking, or your hoses running from your radiator to make sure they are not cracked or split. Another thing is check your fan and make sure it kicks on at the right time and it doesn't freeze up when it gets hot.

i have a 99 that ran close to 210. i put a 180 super stat thermostat in it and flushed out and replaced coolant. fixed the problem.

the 4.0 is SUPPOSED to run at 210. putting in a 180 degree thermostat is actually hurting your engines performance

actually your wrong. Any time you can make a motor run cooler, its better. its the same is if you were to put a cold air intake on a car the cooler(and therfore denser) air going into the engine makes it run more efficientlycuz the air fuel ratio is better and also alowing the cylinders to be cooler, prolonging the life of the engine. there is no set temp that an engine is supposed to run at. Yes running too cold leads to other problems, but it is not bad to put a stat in that opens at a cooler temp. he is actually saving the bearings prom overheating.

when you changed the thermostat did you make sure that there where no air bubbles in the system before calling the job done? if you didn't that could be causing the fluctuation in temp. Also try swaping out the stock radiator fan for one that moves more air over the radiator.

actually no your wrong. the jeep 4.0 was designed to run best at 210 degrees. yes, your right about cooler air, cold air mixes better with fuel so it is more combustible, thus burning better. but the 4.0 engines performance is at its best once it reaches its running temperature. 210 degrees. look it up.

if vehc overheat going down the road, the rad is clogged. ram air cools the coolant in rad. If not enough coolant can flow through rad. Eng will overheat. At idle it doesnt need as much to cool eng. take elect fan out, allow eng. to warm up to operating temp.(t-stat needs to open) CAREFULLY reach down in and feel rad. Ck for cold area. (usually at bottom of rad.)

SOME KEEP SAYING WHAT THE JEEP SPEC CALLS FOR LETS NOT FORGET THAT WAS BEFORE JEEP REALIZED THEY PUT TOGETHER A FAULTY MOTOR

where do you get a faulty motor?

for one the 4.0 is a great engine if taken care of ive owned four of them and the XJs have a problem with overheating i have had this happen on a few of them its the radiator i put in a fail safe thermostat and a three core radiator and it runs cool barely gets to half when i tow my heavy boat and runs great it took me four to find it out but thats what works