After changing the thermostat and water pump on your 1989 Jeep Cherokee it still heats up what could be wrong?

Answer 1

The radiator may be clogged preventing water flow into the engine. With the engine cold, remove the radiator cap. Start the engine and let it warm up to the point where it should open the thermostat. Observe the flow of water in the radiator. If you can't see the water moving, the flow is being impeded somehow. Also suspect the coolant temperature sensor (located next to the thermostat housing).

you may have an air pocket in the coolant lines preventing proper flow of the coolant.be sure to flush the system thoroughly to remove any airpockets. There is a bolt on the thermostat housing which you can remove (when cool) that by-passes the thermostat, allowing you to fill coolant. Use a small funnel and fill to top, then replace the bolt. This will allow the coolant in the block to reach water pump, heating thermostat, and circulating the coolant through radiator, etc.

• • • • Also, remove the overflow bottle, and using a stiff wire (coat hanger in my case) make sure the pipe connecting the bottle to the system is clear. My case I had a calcium-like blockage stopping flow and creating air/steam in system.

I just changed the water pump, thermostat, flushed the system. Make sure no air is in the closed presurized coolant system, air in the system stops the water from moving around.

Usually the fan clutch deteriates after the water pump went.

It could also be that your oil pump is on the way out. Do you have good oil pressure via the pressure gauge? Are any "check engine" lights coming on? Good luck, Badgirl.

check the coolant bottle for cracks etc. and also check the pressure capon the bottle. the cap can be no good and appear to be fine. best advice.....go buy a new pressure cap from the dealer and see what happens. i changed almost my whole cooling system before i did the bottle and cap.....nothing got it to run cool until i bought and installed them!!!

I, too replaced thermostat, radiator cap, ect, even the cap on the coolant bottle. Finally, I had to replace the plastic bottle itself. Jeep dealer told me they are plastic, and therefore they warp with age.