1994 jeep xj overheating
 

HELP my XJ WITH 4.0 is overheating 230 +after driving 20 or so miles at highway speeds in the heat of day with ac turned on. It runs cool (200 degrees) when ac turned off. I have a new dual core aluminum radiator with a working three electric fan set up and new 195 degree thermostate. The coolant looks clean no rust and no evidence of oil in coolant.

I live in Phx.. with ac on and driving on the freeway I usually see temps 240/250ish I have been told as long as it doesn't go into red or puke coolant run it jeeps run hot and just deal with it...and thats from a master tech/ jeep owner

I am in Tucson, not too far from corona De Tucson. It shouldn't run 240 unless something is wrong in my opinion. With Ac on, it should run 220ish in my opinion

​​​​​​My thoughts exactly...but I do know jeeps have heat soak issues. Also if the Jeep is modified it could be strianing the system even more. I have replaced all cooling system parts added trans cooler, hood vents. Prob spent close to 1500 on cooling system alone and nothing ever changes..just runs hot for me. Hoping when I put a new engine in (currently rolling with 262k) it fixes my heat issues...

If it gets that hot with the Ac on, then something isn't working properly. Either a flow problem, blockage in the heater core, collapsed radiator hose... In the near future, I plan on upgrading everything on mine

I have upgraded everything on mine and still runs 240 with ac turned on while on freeway

Well at least I am not the only one!

my be its because its been above 105 14 days in a row

yeah mine did not like the 122 day. its really hard to cool something off when its prob 130 coming off the asphalt.

may be waite to use our xj for every day driving until it cools down LOL

I use mine daily. Black bedlined and windows down

Yeah you guys seem way to cool with the idea of running 240....thats is way too high. A cooling system that's with no issues should be able to handle the heat.

See? I said the same thing. Its not suppose to run that hot unless something is wrong. When mine climbs above 220 for any reason, I freak out

My whole system is new 97+ e fan zj fan clutch new water pump t stat t stat housing upper and lower hoses 3 core radiator. Hits temps like that every year nothing changes it.