I just noticed that if my JKU is idling for about 5 minutes the temperature gage rises and then a warning light come on. All other times driving, the gage is exactly top center and doesn't waver. Only sitting still idling causes the temp to rise. I am out of factory warranty but have lifetime (though there is a deductable). What do you think the cause is and how do you suggest I investigate?

 

I assume you have a two speed fan like the one in my 2011. Is the cooling fan turning on and is it coming on at low speed or high speed. Have you been off roading in any mud that would have plugged up the fins in the radiator?

 

I'll check the fans. It is a 2012. All stock. Never been in dirt or mud (sad, but true).

 

There is a rheostat located on the fan shroud to the fan motor that controls the low speed that can go out. Usually the high speed fan will still kick on but not before the motor reaches a higher temperature.

 

So my Chrysler lifetime warranty has a deductible. I forget if it is $50 or $100. Should I try to fix this myself, or take it to the dealer?

 

Without a doubt take it to the dealer. Reason being the 50 or 100 is cheap insurance and if something else fails downstream after you "fix" it they can wash their hands of it blaming you. Like a motor overheating and causing damage? Hey just my $.02

 

My check engine light came on shortly after this overheat experience this morning. Error code is P0480 for fan control circuit. I'll give the dealer a call.

 

Yep, mine was the same thing, same year 2 months ago. Dealer said the radiator had cold spots and kept asking me if I mixed different types of radiator fluids. I haven't touched that radiator except to check the fluid level.

Long story short, dealer wanted $600 to replace since it was out of warranty at 40,000 miles. I got a new one put in at a radiator shop for $200.

If you are out of warranty, shop around

 

Are you no longer under the normal 36 month/36k mile warranty? I would think you're still in the powertrain warranty, but I don't know if this falls under that umbrella.

 

Nope. Been down that road. See if this makes sense. The radiator is not covered under the 36K warranty, nor is the thermostat, but the water pump is. I guess if it directly bolts to the engine block, that's what's covered. I guess since the thermostat bolts to the water pump which bolts to the engine, that's not considered part of the "powertrain (engine"