3.6 overheating
07-27-2017, 04:35 PM
#1
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3.6 overheating
My 13 JK is overheating. The electric fan stays on constantly. Seems to mostly overheat at speeds 20-55. Sitting at idle, I have never it overheat. Checked the coolant at the fill and it appears to be full. Overflow is nearly empty. What do you all think? Do these things have thermostats? Could it be the pump?
07-27-2017, 08:40 PM
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Knee jerk reaction tells me you thermostat is stuck open. The coolant doesn't get enough time in the radiator to cool down so the whole system heats up eventually and the fan stays on trying to cool the fluid.
07-28-2017, 02:30 AM
#3
JK Jedi Master
If the problem is the thermostat, it would be it's stuck toward the closed position, causing the water to not carry enough heat out of the engine.
07-28-2017, 06:20 AM
#5
JK Jedi Master
Yes they do have thermostats. Ic could be the pump--they are just plastic impellers anymore. To check the thermostat, wait for the engine to be completely cold. Start it and feel the coolant hose on top. It should be cold until the temperature gets to some value where the thermostat triggers (sorry, I have a 3.8 and am not familiar with the 3.6 value--bet Ronjenx can provide that, though).
Another thing: Have you done anything to the grill openings? If so, what? Many of the aftermarket products reduce airflow to the radiator.
You also mention that "overflow is nearly empty". Fill the coolant reservoir to the minimum line when it's hot with the proper coolant (OAT certified for Chrysler vehicles). If it drops too low when hot, then when cool it ends up sucking air into the coolant system. Get a bubble in the right spot and that can cause weird problems (overheating, heater not working right, etc), while your radiator looks full at the cap.
Another thing: Have you done anything to the grill openings? If so, what? Many of the aftermarket products reduce airflow to the radiator.
You also mention that "overflow is nearly empty". Fill the coolant reservoir to the minimum line when it's hot with the proper coolant (OAT certified for Chrysler vehicles). If it drops too low when hot, then when cool it ends up sucking air into the coolant system. Get a bubble in the right spot and that can cause weird problems (overheating, heater not working right, etc), while your radiator looks full at the cap.
07-28-2017, 07:18 AM
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Yes they do have thermostats. Ic could be the pump--they are just plastic impellers anymore. To check the thermostat, wait for the engine to be completely cold. Start it and feel the coolant hose on top. It should be cold until the temperature gets to some value where the thermostat triggers (sorry, I have a 3.8 and am not familiar with the 3.6 value--bet Ronjenx can provide that, though).
Another thing: Have you done anything to the grill openings? If so, what? Many of the aftermarket products reduce airflow to the radiator.
You also mention that "overflow is nearly empty". Fill the coolant reservoir to the minimum line when it's hot with the proper coolant (OAT certified for Chrysler vehicles). If it drops too low when hot, then when cool it ends up sucking air into the coolant system. Get a bubble in the right spot and that can cause weird problems (overheating, heater not working right, etc), while your radiator looks full at the cap.
Another thing: Have you done anything to the grill openings? If so, what? Many of the aftermarket products reduce airflow to the radiator.
You also mention that "overflow is nearly empty". Fill the coolant reservoir to the minimum line when it's hot with the proper coolant (OAT certified for Chrysler vehicles). If it drops too low when hot, then when cool it ends up sucking air into the coolant system. Get a bubble in the right spot and that can cause weird problems (overheating, heater not working right, etc), while your radiator looks full at the cap.
No obstructions in the grill.
Ok maybe I am just low on coolant. But how could I lose coolant though without a leak? Also, I do not see a level indicator in the overflow reservoir. Think I may just go buy a gallon of OAT and a thermostat but see if the fill helps before going into the thermostat.
07-28-2017, 08:47 AM
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Originally Posted by landis76
No obstructions in the grill.
Ok maybe I am just low on coolant. But how could I lose coolant though without a leak? Also, I do not see a level indicator in the overflow reservoir. Think I may just go buy a gallon of OAT and a thermostat but see if the fill helps before going into the thermostat.
Ok maybe I am just low on coolant. But how could I lose coolant though without a leak? Also, I do not see a level indicator in the overflow reservoir. Think I may just go buy a gallon of OAT and a thermostat but see if the fill helps before going into the thermostat.
I wouldn't spend the money on the thermostat until you narrow it down to that. Though it's not an expensive part, it may not be needed and I've had vehicles that never needed a thermostat replacement and some that have. I'd put that money towards a temperature gun which could be useful in troubleshooting this and many other issues. How long does it take from start up to over heat? Try to turn the heater on as it comes to temp...Does it blow hot? Does it noticeably (not sure if you have another source of reading or just the gauge on the dash) reduce the temperature?
-Brad
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07-28-2017, 08:50 AM
#8
JK Junkie
Do research on coolant. Make 100% sure you get the right one for your Jeep. 2013 was a transition year. Mixing two types of coolant has the potential to cause a disaster (hoat vs oat).
