2012 JKUR Overheating Issue
#21
JK Newbie
Thread Starter
UPDATE:
Got some more work done on it this weekend. The combustion leak test appeared to be negative, although I wasn't able to get the motor fully heated before the radiator started boiling all of the coolant out. Tried it again AFTER it boiled all the coolant out and still appeared to be negative. So I swapped the damn water pump, no improvement. The old WP looked fine. Burped, vacuum bled, and opened the thermostat bleeder valve repeatedly, still no better. Don't see how it could be the radiator since it holds pressure and vacuum well, has excellent flow rate when flushing, and looks clean enough to drink out of (I'm about to drink the orange Kool-Aid dealing with this nightmare!!! )
I guess I am going to try swapping the Autozone thermostat with a MOPAR unit. Maybe also see if I can get a more definitive combustion leak test without boiling over. Otherwise I am at my wits end here and about to take it to a Jeep shop to see if they can help figure it out.
I do have an exhaust leak and have recently read about bizarre situations where this can cause overheating. Is anyone familiar with this?
Got some more work done on it this weekend. The combustion leak test appeared to be negative, although I wasn't able to get the motor fully heated before the radiator started boiling all of the coolant out. Tried it again AFTER it boiled all the coolant out and still appeared to be negative. So I swapped the damn water pump, no improvement. The old WP looked fine. Burped, vacuum bled, and opened the thermostat bleeder valve repeatedly, still no better. Don't see how it could be the radiator since it holds pressure and vacuum well, has excellent flow rate when flushing, and looks clean enough to drink out of (I'm about to drink the orange Kool-Aid dealing with this nightmare!!! )
I guess I am going to try swapping the Autozone thermostat with a MOPAR unit. Maybe also see if I can get a more definitive combustion leak test without boiling over. Otherwise I am at my wits end here and about to take it to a Jeep shop to see if they can help figure it out.
I do have an exhaust leak and have recently read about bizarre situations where this can cause overheating. Is anyone familiar with this?
#22
JK Jedi
you should be doing that combustion test via the reservoir, not the radiator.
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Digitek14 (09-26-2022)
#23
JK Newbie
Thread Starter
Got it. I thought that may be better since it would allow me to get the motor heated up, but the kit specified with the radiator cap off oddly. I also wasn't sure if that would just be fresh air in the reservoir since it's exposed to the atmosphere from the overflow tube. I'll try another combustion leak test from the reservoir and swapping the thermostat to MOPAR here in the next day or so.
#26
JK Newbie
Thread Starter
#27
JK Newbie
Thread Starter
Update
I was gonna recommend the same as i just kinda went through the same issue after another forum member mentioned that Autozone and Oreillys thermostats are prone to failing, or not functioning correctly out of the box. In my case, the autozone brand wouldnt open fast enough to control the temps and i would see the same temps the OP is seeing. Temp would creep all the way up to 245 degrees before it fully opened and allowed flow. I went with a MOPAR brand, did three or four bleed cycles and now i dont see over 226 in the worst conditions but around town, in 100 degree ambient, it will hover around 212 degrees, which i am fine with. Thats with a big ol winch blocking airflow as well.
Any other ideas? At least it is drive-able now!! Thanks for the help/input from all of you!
#28
JK Newbie
UPDATE: Swapped the AutoZone thermostat with a MOPAR unit. The one from AutoZone was pretty clearly inferior, didn't even look quite the same. At first (like you described) it would still overheat, but this has gotten progressively better over a few bleed cycles. It is mostly fixed but still does overheat a bit more than before when climbing hills on the highway.
Any other ideas? At least it is drive-able now!! Thanks for the help/input from all of you!
Any other ideas? At least it is drive-able now!! Thanks for the help/input from all of you!
#29
JK Newbie
Thread Starter
Can't recall, but do you have anything blocking the radiator? winch? aftermarket grill? bumper? etc. My first thought now, if you have the system burped correctly and the thermostat is opening all the way, is that it's an airflow issue. Even those cool little grill inserts will make a huge difference on the highway. Remember that these jeeps are designed to run at a higher temperature already, so anything added to the front will reduce its ability to do so drastically. Larger tires, lower gears will add to the struggle as well.