So, i bought a 95 xj, and it over heating and boiled over, so i started replacing the most obvious things first, thermostat, housing, upper and lower hoses, it still over heated, thermostat was bad, bought a brand new one from napa, along with a radiator cap, it still boiled over, so i replaced the radiator, then checked the water pump, the old one was fine, but i replaced it anyways, and changed out the sensors, i flushed the system again and refilled, got all the air out too, and ran amazing for a day or so, then overheated, i raplaced the head gasket and checked the compression and checked the fluid for hydrocarbons, nothing, what else could it be? Ive replaced everything, i have a 180 degree thermostat from napa, brand new water pump, housing, and both fans work and spin the right way, the system has clean fluid too, im so confused on this one

 

What kind of traffic/driving conditions are you in when it overheats? Does it overheat at highway speed? Or does it only overheat when you're sitting still or moving slowly in traffic?

 

Fans working correctly.

 

Is your coolant 50/50? Straight coolant will not cool effectively.

 

Im driving about 30 mins in normal traffic, at about 45 mph, and as soon as i stop and shut it of, it boils out of the plastic over flow

 

Fans are working properly and going the right way, on of my fan shrouds is off, and i do have 50/50 coolant to want

 

clutch fan?.....and what is the temperature reading? temp reading while driving and temp reading while idling....better to read temps with a scanner than trust the gauge

 

the clutch fan is new too, everything it working fine, everything is brand new, but it still over heats, i do have the idiot lights some how. but they do work right, when i let it idle and check the temp, its at about 210 while idling, and then while running, at about 180-200, but then all the sudden, the light will come on, and as soon as i shut it off, itll heat up and start filling up the over flow and boil out a little bit. last night when it over heated, i pulled over and checked it with an ir thermometer, it was at about 225 after shutting it off.

 

Having a fan shroud missing will not draw air flow correctly. Does it heat on the freeway? Normally above 60 mph fans are not really doing much. It may be a way to see if it's air flow problem by running it on the highway to see if it heats.

 

this could be it, but it still over heats going like 55 around town, so i have no clue, i may go grab a shroud soon and check it and see

 

Could the condensor be clogged with debris? It would block air flow through the radiator. And did you change the temp sensor? Maybe your electric fan is not kicking on soon enough. Running lean or exhaust blockage could also cause an engine to run hotter than it should.

 

I'm wondering what the previous owner did-if he used some stop leak or something and it has a clog somewhere.

I would be great if you could get a scanner or torque app with obd2 adapter and looks at temps while driving

 

ive checked temps while driving, it checks out okay. itll only do it randomly. the only thing i can think of, is that the block is clogged somewhere and not allowing the fluid to flow properly.

 

He has a '95. Not OBDII. Torque won't work.