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Discussion Starter #1
I have a 2011 JK unlimited with 36k miles that I drive mostly in-town. I may just be paranoid but I don't remember my radiator fan running so much until recently.
I have not had any problems with overheating. My temp gauge heats up quickly (usually within 5-10 mins) and stays near the center mark. However, it seems like my fan constantly runs once it warms up to that point. Ambient temp has ranged from 40F-80F but doesn't seem to make a difference in how quickly it heats up or the fan running once it hits center mark. I don't run the A/C or heater. Usually radiator fan runs in low but will kick to high sometimes, so the coolant temperature sensor seems to be working properly.

Is this normal for in-town driving? Like I said, maybe I am just paranoid but I have had this jeep for almost a year now and never really noticed how much the fan runs until a few weeks ago.
 

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It could be a few different things.

Have you been mudding or stream crossing lately? That could block the radiator and A/C condenser fins compromising cooling efficiency.

The thermostat may be sticking, causing the engine to run too hot, which can make the fan run excessively.

The coolant temp sensor may be giving the computer a higher than actual temp reading, making it kick the fan on when it's not needed.

So, look at the radiator/A/C condenser fins for any sign of blockage.

If that's OK, buy or borrow an infrared temp gun and point it at the base of the thermostat housing while the engine is idling and warmed up. The fan should come on when the temp is about 215°F, and turn off when it drops to about 195°F.
 

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Discussion Starter #3
Thanks for quick reply. The radiator both front & back seem really clean. I used an IR gun to confirm that the fan is kicking on around 215F, but it never drops back below 195F (while the engine is running) for the fan to turn off.

Does this indicate a sticking thermostat?
 

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Thanks for quick reply. The radiator both front & back seem really clean. I used an IR gun to confirm that the fan is kicking on around 215F, but it never drops back below 195F (while the engine is running) for the fan to turn off.

Does this indicate a sticking thermostat?
Could be. It's not expensive or hard to put in a new one.

If you have never had the radiator under water you can assume it's clean by looking at it.

If it has been under water, the only real way to know it's clean is to separate the the two (A/C condenser and the radiator) and look at both sides of each.
 

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My fan kicks on at 215 and off at 194.
If its not kicking off somethings not right. Would start with thermostat if radiator is clean.
 

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Discussion Starter #6
FIXED: Replaced my thermostat tonight and during my test drive the temp gauge stayed just to the left of dead center. Did the boil test on my old thermostat and it never fully opened.

Thanks guys.
 

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FIXED: Replaced my thermostat tonight and during my test drive the temp gauge stayed just to the left of dead center. Did the boil test on my old thermostat and it never fully opened.

Thanks guys.
That's good news!
 
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