when i got the jeep the head was off of it along w/ radiator and couple other things. i got it all back together last night and its over heating. its got new thermostat and water pump i cant figure out what the problem is. has any1 had this problem? any help would be appreciated

 

Did you put a new radiator in it? There may have been a reason it was off

 

the one that came w/ it was the wrong one for it so i got a used one from a friend that was workin when jeep was parked

 

I would try "Burping" the system first. Does the electric fan come on at all? and if that doesn't work (burping) you may have either a cracked head or block...Tj

 

X 2 on burping air out. Leave the cap of the radiator and the overflow tank. Fill the radiator and start the motor and turn the heater on high. Run it until the T-stat opens (until you can look in through the radiator cap hole and see the water moving through the radiator. Top the water level off and watch it for a couple more minutes and top it off again. Put the radiator cap on and shut the motor off. fill the overflow tank to the HOT line. This is the only way I've found to get all of the air out of 4.0 cooling system.

 

there is no leaking of water anywhere so i know the is no crack. and no the electric fan doesnt turn on. but it goes above 260 and electric fan wouldnt be the cause of that i dont think??

 

How high is the temp going and how quick does the the engine start overheating. Some times you can pull the spark plugs and tell if possible head or head gasket crack by the different color spark plug tip. On some models the head cracks at Between 3 and 4 spark plug on 4.0. Electric fan cycles on and off with a/c on and above about 115 to 130 on some models

 

My 96 was overheating when driven over 15 miles at a time or when traveling up a graded hills, the ones over 2 miles long on the interstate. I changed the thermostat, flushed the system and was doing ok, until the warm weather started. Pulling my tent camper was ok on flat roads, but inclines would push the temp guage almost into the red. One sugestion from my jeep mechanic friend, was to flush the radiator fins from the engine outward. The radiator collects dust that over time will dry and clog the openings. I found while flushing the radiator with water that my fan clutch seemed to be turning slower than the surpentine belt. When the engine is hot the fan should be turning as fast as the belt, since the clutch is engaged. I replaced the clutch (about $65) and Have not overheated since.

 

i had a valve job and the head sufaced so i know there isnt a crack in the head and i have new gaskets all around also. the temp goes up to above 260 in about 2-3 mins from when i crank it. will or could burping it bring the temp down to where its supposed to be(about 210)

 

Yes, air pockets trapped in your "pressurized" cooling system will cause overheating in a heartbeat.

 

its not the renix style it has a cap not sure if by pressurized you meant the closed style

 

any1 know??

 

No, my 91 XJ has the newer open style cooling system. They can get air pockets trapped, too. Just not as big of a PITA as the Renix closedtype, to et the airpockets out. You also want to have your heater turned on so no air pockets get trapped in the heater core or hoses that can move down the line later and cause you headaches later.

 

mine is not the renix style its the open style