OK so, here is the problem: My engine overheated and died after this long trip my wife was making (over 100mi) had to tow. Changed out the 4.0 engine (used 300 bucks from grand cherokee) and it worked fine locally. On the way back going up the mountains the engine`s temperature startet rising up to the first line after normal temperature, than it suddenly went up to red line, I pulled over and aid the engine to cool again, there was coolant coming out of the reservoir when I first stoped, countinued the trip having to stop 3 more times (I pulled over *** soon as it overheted) you can see the temperature go down to just over normal in the blink of an eye. This doesnŽt happen in any other driving condition, exept whe I go over that mountain. Since than I replaced all the hoses, water pump, thermostat, put in an aftermarker 3 line radiator against old 1 line, flusher the cooling system, burped it several times with nose up; Im about to make it climb like 90 degrees to try to burp it again. By the way going up these mountains heat raises SLOWLY than flash to redline temperature. My last engine was blown head gasted and cracked head, I know what an engine does when is blwon, his one is not. I,ve been trubleshooting this cherokee for like a year now and nothing different. I just take my other car to go over those mountains. I cant live like this, all the fun is behind the mountains, north: mountains, south: mountains, west: pacific ocean. Please HELP!!!! IŽll be driving over the mountains on the cherokee today, IŽll be makng stops to prevent it from overheating, and to test the burp I did this morning, It actually took 2 gallons of 50/50 anifreeze, had to do it slowly, took me like 2 hour. Thanks so much for any ideas you can come up with, IŽll be answering questions tonight after like 9pm Pacific.

 

BURPING the COOLING SYSTEM
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www.lunghd.com/Tech_Articles/...BurpAirMod.htm


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No worky bro

 

I just tried what the above website sugested, I coulnŽt find the part but, I took one of the heater hoses off to mimic the upgrade, there was no air, nose up, didnŽt take any more antifreeze. Going on trip now. Thanks dogh.

 

I ran into a similar circumstance in my '95 XJ, and replaced everything in the rig cooling wise. Still, I had the overheating problem. One day, when I had the engine running, and reached in the window to shut it off, and happened to be looking at the engine at that time, and when the key went to off, the fan clutch allowed the fan to still run (fast), then wind down slowly. I replaced the fan clutch the next day, and it's been dandy since then. Who knows, this might be the problem. My buddy had a Ford pickup that had the same problem, and a new clutch cured his problem also.