Hello, I recently replaced both the thermostat and the temperature sensor, in my 97 xj, country 4wd automatic. The jeep will run fine and for as long as I want if I'm driving staying around 210 degrees. However whenever I stop, and let it idle within 10 minutes the check gauges light comes on, temp goes to 250, and then after a few minutes the jeep overheats. Any ideas? Also I had the smallest leak from the thermostat housing, I have water and coolant in the car, but haven't had to put any in since I did the repair. It's been a week.

 

Waterpump and radiator. Your '97 is old enough to vote now and is a few years from drinking age. Has the cooling system ever been rebuilt that you know of?

 

Not to my knowledge I got it stock completely about 2 years ago with 55k on it , I have 85k now, could it have anything to do with the small leak?

 

Sounds like the fan clutch is bad.




https://www.cherokeeforum.com/f2/fan-clutch-bad-13728/
https://www.cherokeeforum.com/f2/how...ch-bad-165904/

 

First thing I do when I buy a cherokee is replace the thermostat, water pump and radiator. It's cheap and an easy job. No money better spent on your cherokee than coolant system.

 

I would be cautious driving her around, nothing kills a 4.0 like heat. But i would definitely spend the money and get a new water pump and radiator (preferably aluminum) then flush the system out with some prestone coolant flush. then see what happens. if it still over heats then i would agree with dumajones and check the fan. good luck!!

 

Yes do the radiator >$100, water pump, fan clutch (upgraded) and a very good clean and flush of engine block and heater core. Needles to say new rad hose's and heater hoses with a fan belt.


At those temps the electric fan should have kicked in and been running also check it also.

 

Classic symptom of a fan clutch failure. While you're driving, there's enough air flowing through the radiator to keep the system cool. Once you stop, the fan clutch allows the fan to freewheel until you reach operating temp, at which time the fan is supposed to lock up and start pulling air through the radiator. Yours probably isn't doing that, so it overheats.

It costs $35 to swap in a new one, and the basic repair involves 8 bolts. It can be done without removing the radiator, but it's easier if you pull the upper radiator support to be able to tilt the radiator away a bit to give yourself a little more room.

I wouldn't waste the time or money on another radiator or water pump until you replace the fan clutch and maybe check the electric fan. If it's not overheating at speed, your radiator and water pump are doing their jobs.

 

Do the easiest first! Make absolutely sure that you have purged the system of all air! I had this problem couldn't figure it out after swapping ALL cooling components. Took it to 2 shops 1 being a dealer. Let it sit due to no resolution, started looking for a long block. Went and fiddled with it after lots of research on this forum (drilled small hole on thermostat) and had it running perfectly in about 30 minutes.

 

A sign of this is an inactive electric automatic fan clutch. Air traps/restricts the coolant and doesn't get the thermostat hot enough to activate. May take bit to purge it all.

 

I had those symptoms last summer but the electric fan would kick in and keep it between 115 and 130. I started with the simplest fix: Fan clutch. Never goes over 210 now.

 

This. All of this. There is no reason to blame the rad or water pump, otherwise the engine would overheat when it's making the most amount of heat, not sittig at idle...