86 cherokee laredo

[bigdza]

Jeep is having overheating problems for a few months. Several months ago it started overheating and overflowing (closed circulation system) whenever we drove in medium to heavy traffic. Took it to shop, they said head was cracked...didnt have the money to fix, so they changed water pump. and put in a new radiator. We used a "seal" product to fix the supposed crack. (they did a compression test and it came back fine, and we've never had antifreeze mixing with oil) Anywayz, After we used the seal product it seemed as though the fluid wouldn't be "accepted" through the overflow tank until one day it overheated and all of the sudden it gulped down over a gallon. Since that day its been running perfectly fine!!! THAT IS....until my girlfriend decided to drive into New York city at rush hour. So needles to say we overheated in the holland tunnel of all places, and had to drive it with the temp gauge maxed out for a good 5 to 7 minutes. Somehow the car is still running but we're back to the point where it is overheating every 10-15 minutes BECAUSE the fluid is overflowing and there is nothing in the circulation to cool it. I pour a gallon plus in and it stays cool for 10 minutes and then it starts boiling over and empties....then we have to stop wait and pour more water in....go another few miles....repeat etc. I have no clue whats left to do. the thermostat is open. i've got both fans running (one is rigged straight to the battery bypassing the relay) its gotta be something in the circulation. I'm no mechanic, only thing i know about cars/jeeps is from the problems with this one. ANY ideas...or ANY advice is appreciated. I really appreciate anybody who has read all of this. thank you so much everyone.

P.S. anybody have a diagram or can tell me more about how to find the radiator hose(bottom one) that may be crimping?

 

[54cj3b]

crawl under the jeep and look if you own a jeep you shouldnt be afaid to get a little dirty but doubt its a crimped line
you most likely have air in the system remove your thermostate and replace before you put in new thermostate drop 2 alkaselzers in then install thermostate and gasket before putting neck back on tighten up bolts refill system park jeep on a hill nose facing down run jeep with cap off about 10 min till thermo opens add water as needed let run another 10 min watching bubbles perge from the system after therres no more bubbles the systems purged replace cap and you should be good to go in a day or so park on a hill again nose down do same thing to be sure all air is out of system

 

[bigdza]

can i just remove the thermostat for the summer time? or is it a god idea to have one in there? Definatly not afraid to get dirty. i already am pretty dirty :^) but i just dont know where the hose that crimps would be. And about the alka seltzer....um where do you want me to drop them in? in the overflow tank or where the thermostat is? I think air in the system is the problem actually. It seems to fit all the symtoms. and like i said last time it all of the sudden started gulping down fluid it ran fine for a good 4 or 5 months. so yea. I'l try to burp it. Thanks a lot.

 

[MudderChuck]

My dyslexia strikes again, looked at you model year 86 and saw 89 the first time. LOL What engine do you have?
Overheating in traffic (especially with a new radiator) is often a bad mechanical fan clutch. And/or your auxiliary fan isn't coming on, it should kick in when the temperature gets much above 212-220 (temp. gages lie a lot).
Getting the air out can be a pain. I squeeze the top radiator hose together a half dozen times with the motor running.
Possible your heater valve is gummed up, part of the flow that helps to purge air is through the heater valve and the coolant tank.
Also possible your radiator cap is gummed up and not releasing the pressure like it should.
In my experience you can have multiple things going on that add up.

The bottom radiator hose is the one from the drivers side bottom of the radiator to the water pump, 1 1/2" diameter (I think), kind of hard too mis looking from the bottom up. The view of the bottom radiator hose can be blocked looking down. If you squeeze it together, you should feel a spring in it. If you can squeeze it flat without using much pressure, it can cause grief at high RPM's (it my collapse).

 

[bigdza]

I looked at the radiator cap (which is a plastic cap that sits on the overflow resevoir and when too much pressure builds it supposed to lift up and let pressure out...i have a closed coolant system) anyway, i looked at it and it seems to have a chip taken out of the plastic "ring" that is surrounding the spring...i'm trying to find a picture to see if thats what its supposed to look like, ,but i guess i'll go buy and new one and compare them. If the cap is broken could that be causing all of this trouble?

 

[MudderChuck]

If the cap is loosing pressure it can cause your coolant to boil at a lower temperature.

 

[SteelHeadz]

Yep, i would replace the cap first. A minute leak in the cooling system would make the entire system overheat.