The notorious Cherokee overheating, heat not working thread.

92 Cherokee 4 door auto 4.0

Overheats when started, idling, driving etc.

If i pull the drain plug out of the bottom of the radiator and pull the radiator cap off and run the garden hose through it while running it will stay where it's supposed to (180* thermostat).

Also the heat does not get warm regardless of where the temperature reads, i dont notice a noticeable difference in temperature of the hoses going into the heater core either.

I also pulled my thermostat temp sending unit on the trail to try my friends and noticed that in his thermostat housing there was antifreeze just sitting in there while in mine there was nothing?

Kinda stumped on what to do or go from here... I havent used any flushing products but like I said I flushed it with the hose and still we are overheating...

Thanks!

 

Last water pump replacement was?

 

Have u tried replacing any cooling system components?

 

heater radiator clogged

 

Definitely sounds like water pump not functioning, or something impeding water flow.

 

Not sure if the water pump has ever been replaced. At 265k Im sure it wouldnt hurt to replace it.

Is there anyway to check it?

 

yes pull it off and look then put a new one on...

 

Pulled off the old water pump, it was fine. Spun fine, impeller was in good shape, nothing looked to be issue there.

Is there any 1 place more common for these cherokee's to clog than other places?

 

Both heater hoses at the firewall should be very hot when touched. How old is the radiator and fan clutch.

 

I think the key thing here is that when he pulled the temp sending unit he couldnt see any antifreeze. You should be able to see the antifreeze and since you cant you have a leak. If you find where the antifreeze is at its highest point then you know your leak is somewhere at or below that antifreeze line.
I had a leak at my thermostat housing and when I pulled my heater hose there was no antifreeze in the line. I pulled off my thermostat housing and you can see that the antifreeze line was directly where the leak was. Just a good troubleshooting tip I picked up.
I say fix the leak and then start spending money on components cuz its cheaper to buy a hose than a new radiator.... Just sayin.

 

If its leaking you just have to pressure test the system. If you don't have your own, I believe most auto parts stores rent them. The PSI you pump it to should be on the radiator cap.

 

I just noticed tonight that the radiator has a leak in the plastic tank on the driver side. It's leaking profusely which would lead me to believe that its not able to pressurize the cooling system leading it to the overheating?

I will be putting a radiator in it tomorrow, hoping for the best.

Thanks for all the reply's

 

That sounds like it! Let us know how it goes.

 

I replaced the radiator and it still overheated so I went ahead and pulled out the thermostat, that helped a little bit but once again it still overheated. So I went ahead and flushed it with the drain on the bottom of the radiator open and the garden hose running through the top and like before it stayed cool, very cool. I closed the drain and let if idle for 5 minutes or so with the cap off and it stayed cool. I put the cap on and drove maybe 3 or 4 miles and it once again got hot.

I pulled the dipstick to check the oil and it was a light brown like coffee with a lot of creamer in it..

I'm beginning to think the head gasket is out. Cylinders 2 and 3 have lower compression that the rest..

How bad is it to replace the headgasket? Time? Price?

It will be something I would do myself and doesn't look like its too hard to do..

In the mean time does anyone have any suggestions to the overheating?

 

Your head is also suspect at this point. How hot have you ran it?