HMCJP98

1998 Jeep Cherokee Limited, 4.0L, Auto. Trans.
When the car sits and idles for a long time with the A/C engaged, I notice the Temp Gauge creeps up. The Check Gauge Light comes on. So then I check to confirm whether or not the car is running hot as the Temp Gauge indicates. I find that it is NOT.
I then drive the car. In about three to five seconds later the gauge goes back to normal and the check gauge light goes out.
I’ve had this issue for quite some time but to this date, I have yet to resolve it.
What could be the problem here???
This is what I’ve done as a precaution, just in case.
Replaced the thermostat, the Temp Sensor, Flushed the cooling system, I’ve checked to make sure both electric & clutch fans are operating correctly, there are NO LEAKS internal or otherwise, the car shows NO SIGNS of overheating such as boiling over or anything to indicate such. The temp gauge moving over to the right while idling is the only issue.
I have driven this Jeep literally for more than four hundred (400) miles with no overheating issues.
So again, I ask, what is the issue with this temp gauge???
What am I overlooking here??? Where do I look next???

djb383

How are u confirming that it's not running hot? Unless u have recently replaced the belt driven fan clutch, water pump and radiator, I'd suspect those. If coolant is good and rad cap is good, coolant can easily reach 250F and not boil but 250F is way too hot.

HMCJP98

Well, I do know this, there would be no way I could drive this vehicle as far as I've done without some overheating issue of some sort along the way. Remember, this problem didn't just begin. I'm the original owner of this Jeep.

wgpinatl

I am having the same symptoms on my 2000. Did you get this resolved?

HMCJP98

Here is what I did.

I replaced the thermostat with a Mr Gasket Hi-flow 195 degree thermostat, installed a Hi-flow thermostat housing, and a Hi-flow water pump.

I can tell you that by my doing these three(3) things it has help quite a bit.

I now believe that when I install either an electric fan (get rid of the clutch fan) and install a 3-row cfs radiator, this just might do the trick in resolving this issue once and for all.

I will be sure to touch base with you as soon as this happens which will be within the next few days.

djb383

So it's been over heating all along? Original fan clutch (13 years old)? Idling, with the a/c on, in hot weather, is the ultimate test of a cooling system. Fans aren't even needed at hwy speeds. The mechanical fan draws some major air at slow/no vehicle speeds IF, and only IF, the fan clutch is functioning at peak performance. Fan clutch performance degrades with age. The "spin test" is not very reliable.