My Jeep is not willing to Cooperate With Me!!!

This thing is gettin quite frustrating. Just the other day i went over the cooling system on it ( replaced heater core, thermostat, flushed whole system, refilled with 50/50 antifreeze and water). It ran great for about 4 days then as I was in an icy parking lot spinning happily it started overheating, ran up to about 235 and stayed there. I stopped and put it in neutral and let it idle ( BTW the electric fan was on the entire time) and the temp didnt go down. After parking at home i can smell antifreeze and hear a hissing sound coming from the bottom left corner of the radiator (looking at it from the front), check the drain plug, its dry but there is a very small amount of moisture on the bottom of the radiator. Could this small leak be enough for it to heat up like that. This sucks since I am low on money.

I have a 1990 XJ, 4.0, AW4

First......JEEPS don't have the word "COOPERATE"anywhere in the system!
When you did all that you said did you change the thermostat?
I always backflush 2 times before I add new anti freeze n water.
Check all hoses and clamps...
Start it up and watch the hoses for bulging,watch the rad for leaks.
Check water pump,lossen the belt,see if you can move the pulley on the water pump from side to side...If you can the pump is a gonner..It should spin
freely.....

The steam you saw could have been from cold snow/slush on the hot radiator. Does your 90 have a closed cooling system? If so you may need to burp it. What happens is that air gets trapped in the thermostat area and the thermostat doesn't open because it's not immursed in hot water. If that's not the problem your fan clutch may be bad.

JoBo

Yes, '90 is a closed system. Had to put a new rad in mine with the front rebuild, and never had to burb the system. Maybe I just got lucky though.
Check carefully for a leak on your rad though. The new one we put in was bad. Seemed fine, but once we finally got the jeep started, it started spitting out the backside in the middle. Had to take it back and have it replaced. Replacement went in np. I'd carefully look over the rad, and see if you can tell where it's leaking from if it is at all. It was really easy to tell where it was spattering from on mine, and was only a couple of miniscule holes too.

Good luck!

Does your 90 have a closed cooling system? If so you may need to burp it. What happens is that air gets trapped in the thermostat area and the thermostat doesn't open because it's not immursed in hot water.

Click to expand...

How should I go about burping the thing?