03 liberty sport overheating

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03 KJ Gal

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My 03 liberty sport is overheating when I sit in traffic or a drive thru. But as soon as I start driving the hand goes back down. I let it sit in my drive until the temp hand registered over normal but the radiator fan never came on. But the fan DOES work if I turn on the defrost. Any ideas?
 

LibertyTC

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How many miles on this jeep? Has any work lately been done to the cooling system? Any leaks or having to add hoat coolant into the reservoir?
Inspect to make sure that the coolant is at the correct level in reservoir! (Hot/cold line)
Also check to ensure that the reservoir cap states 16psi.

The jeep temp gauge should sit in the middle if the gauge & everything else is working correctly.

The electric fan does not even turn on until 219 degrees, but the fans should come on if you select defrost. Use on obd2 reader to see the actual temp being reported.
Yes it could be the fan relay if the fan doesn't come on by 219F.

That being said if nothing's been done to your coolant system, a complete drain & flush along with a new MOPAR thermostat & hoses, even a new water pump may be in order.
Mopar Hoat coolant or Zerex G-05 is the only coolant to be used, and it does not mix well if the wrong coolant has ever been added, justifying a flush if unknown.
 

03 KJ Gal

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It has 240,000. No work has been done. There’s no water leaks. The level is always at the hot cold line where it should be. So if it’s in fact a relay, which would it be? Isn’t there more than one? I did check the one in the fuse box under the hood and it’s fine. Isn’t there one mounted by the battery somewhere? But I thought I read with that one it would show a code. And I’m not seeing that code. And then is that a relay that goes to the actual fan that I see up top of the fan? And does the cooling sensor by the water pump have anything to do with any of it?
 

LibertyTC

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2003 to 2004 changes were made & kinda a cross over year. My 2004 is a 2 speed fan with 2 hi and low relays under hood panel.
& if I remember correctly yours is a single speed fan.
You should have a relay mounted drivers side fender area.
Here is an interesting testing video that should help you out for the 2003.
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LibertyTC

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It would be best to conduct the electrical testing first.
You will have to drain rad and remove the lower rad hose to replace the thermostat. Get a new Mopar thermostat & lower rad hose as well.
You must be registered for see images attach

As always, Mopar Hoat or Zerex G-05 coolant for these jeeps only.
 

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