TJ is overheating

Grant G

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Original poster
Joined
Sep 6, 2022
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3
Location
Mississippi
My jeep is overheating when Idling. The fan is running. Checked water pumps I didn’t notice any leaks. When driving it will go back down to normal temps. It has coolant bought this jeep a couple weeks ago and hoping I didn’t get burned on it. It is an 01 with 93k miles.
 
There are a bunch of write ups from this summer. I know I did one. You have no idea what the previous owner did on this 21 year old Jeep. They could have mixed coolant, they could have tap water that's rusted, who knows.
If you're having this issue, I'd start by doing a flush and refresh. I'd check if its and aftermarket Radiator, and get a Mopar before you can't find them anymore. I'd flush with Thermocure and put a Mopar thermostat, new cap, run the whole process personally I'd drain the block in that process as well.
 
Define overheating.
But regardless of that, it is smart to do a complete refresh of all fluids, this way you have a clean start.
 
My jeep is overheating when Idling. The fan is running. Checked water pumps I didn’t notice any leaks. When driving it will go back down to normal temps. It has coolant bought this jeep a couple weeks ago and hoping I didn’t get burned on it. It is an 01 with 93k miles.
How hot is it getting when idling? That the temperature drops once you start driving it could mean the fan clutch has gone bad and isn't spinning the fan as hard as it should. Without the engine running the fan should be easy to turn by hand when the engine is cold and very hard to turn by hand when the engine is hot. Hayden is a good brand of aftermarket fan clutch.
 
How hot is it getting when idling? That the temperature drops once you start driving it could mean the fan clutch has gone bad and isn't spinning the fan as hard as it should. Without the engine running the fan should be easy to turn by hand when the engine is cold and very hard to turn by hand when the engine is hot. Hayden is a good brand of aftermarket fan clutch.

Did a little work around the house earlier and left it running say 25 minutes when I got in it was 250ish and had steam coming through the vents. I drove it back up to the house to check everything and temp went back down to 210ish
 
Did a little work around the house earlier and left it running say 25 minutes when I got in it was 250ish and had steam coming through the vents. I drove it back up to the house to check everything and temp went back down to 210ish
Yeah that's too hot, I'd check the fan thermostat as suggested above.
 
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The dash from the air vents but it was only after I turned it off

It sounds like your heater core is leaking and as a result your cooling system cannot maintain pressure. Coolant always flows through the core. There is no valve.