1998 weird overheat issue

[jtippett10]

OK, I have a 1998 jeep cherokee limited. 110,000 miles. OK, here is my problem. Last summer I bought my jeep in Kansas City and drove it to Las Vegas where I live. It was fine the whole drive, blasting the AC. When I got it home, I had the coolant flushed and replaced. Soon after, the car started running very hot, and occasionally when stuck in stop and go traffic, would overheat. I changed the thermostat, and then the summer ended. I thought that fixed it, but it came back this summer. I have noticed that if I turn the AC off, it will stay around 215, but if I turn the AC on it will eventually pop up to 240 or so. coolant also boils out of the resevoir when this happens. No oil in the coolant, just got a new AC compressor, new belt, any ideas are appreciated. thanks

[wrightz28]

I just had a thread up in here about my 98 acting the same. The electric cooling fan was barely turning half speed due to resistance through the relays. Eventualy the motor unannounced burned itself up and I was in stop and go traffic with the gauge showing "220" until it started to run like poo and the gauge decided to tell the truth that I was running at 250

I ended up doing what I don't prefer, but seeing it's a known problem with these trucks, I put a new fan in and run it off a manual toggle switch. Now it stays a cozy 210-215 even with the A/C on.

[fredjacksonsan]

The fan can be the problem, but I've also seen a lot of threads in here where the radiator has just enough scummy buildup to reduce the cooling capacity -- in winter it's fine, but when summer comes it's not; just like your vehicle.

A new radiator might be a good option; you don't know how the person before you took care of the coolant, it might never have been changed.

[mastertech1964]

easy check is to start the car and turn the a/c on and look under the hood the electric fan on the left (drivers side) of the radiator should be running if its not look for a burned up relay or a bad fan its possible the connector to the fan was knocked loose also

[jtippett10]

the electrical fan is going when I turn the car on with AC. I am leaning towards radiator replacement. Does anybody have any advice as to what radiator? I can get a OEM reaplacement for cheap, but have read some comments that it is too wussy to handle the cooling load that I need here in las vegas. Should I get plastic, metal, two core, three core? thanks for any insight.

[corbinwaterski]

Bigger is always better, i.e. three core.

[fredjacksonsan]

Metal, three core.

[jtippett10]

update: threw a new three core metal radiator in and cools like a witches titty. no more everheating, and life is good