Overheating JK 3.6
07-05-2021, 05:39 AM
#1
JK Newbie
Thread Starter
Overheating JK 3.6
Wonder if anyone can help? My JK is overheating, it’s ok when you’re driving on road but when going slow off road it overheats. When it overheats there is no warning lights and the temperature gauge shows ok? Could this be the thermostat? Thanks
07-05-2021, 06:07 AM
#2
JK Junkie
If you just let it sit running at an idle will it overheat? I had that problem I my 2012. A connector on the battery which is a fusible plug for the fan became loose and had a bad connection. This prevented a fan from coming on. Though in my case the temp gage did show hot.
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jake_inspired (07-05-2021)
07-05-2021, 07:38 AM
#3
Super Moderator
If you’re overheating and your temp gauge is normal then you have multiple problems. What are the symptoms you’re seeing of overheating? Are you sure it’s overheating and not just hot? Everything gets hot when 4wheeling but that doesn’t necessarily mean overheating.
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jake_inspired (07-05-2021)
07-05-2021, 08:24 AM
#4
JK Newbie
Thread Starter
Yes it’s definitely overheating, it started to lose power and then a few seconds later steam was coming out of the hood. No warning lights show and the temp gauge is normal even when it was steaming and cut out. I’ve checked for mud between the radiator and it’s all clean. This is why I’m so confused as it shows normal? Could it be wrong coolant that has been put in by the last owner? Air in the system?
07-05-2021, 09:32 AM
#5
Super Moderator
If it were me, I’d do a couple things:
First, check your temp sensor. I have no clue where it is so you’d have to do some of your own research here. But sensors can usually be checked with a multimeter for proper resistance at a given temperature. If the sensor is bad then replace it. If it’s good then you have an issue elsewhere whether it’s in the gauge or wiring. I doubt it’s wiring because if it is wiring then your temp needle will likely always indicate cold.
Second, I’d flush the system. Let a shop do it so they can use a machine and cycle fluid through. This will not only get air out but will also get any sludge or junk out of the coolant passages.
After this is done, run the engine at idle in your driveway till it warms up and verify the fan turns on.
If after all this you still have issues, you may have a bad water pump or some other issue. I say to do this “if it were me” because some people have their own methods of troubleshooting. But this is just mine.
It’s important to document details of what’s happening. What was the temp outside when your engine did this. Where did the steam come from? When your engine lost power, was there any noises? Every detail matters so pay close attention to everything.
First, check your temp sensor. I have no clue where it is so you’d have to do some of your own research here. But sensors can usually be checked with a multimeter for proper resistance at a given temperature. If the sensor is bad then replace it. If it’s good then you have an issue elsewhere whether it’s in the gauge or wiring. I doubt it’s wiring because if it is wiring then your temp needle will likely always indicate cold.
Second, I’d flush the system. Let a shop do it so they can use a machine and cycle fluid through. This will not only get air out but will also get any sludge or junk out of the coolant passages.
After this is done, run the engine at idle in your driveway till it warms up and verify the fan turns on.
If after all this you still have issues, you may have a bad water pump or some other issue. I say to do this “if it were me” because some people have their own methods of troubleshooting. But this is just mine.
It’s important to document details of what’s happening. What was the temp outside when your engine did this. Where did the steam come from? When your engine lost power, was there any noises? Every detail matters so pay close attention to everything.
07-05-2021, 09:44 AM
#6
JK Newbie
Thread Starter
If it were me, I’d do a couple things:
First, check your temp sensor. I have no clue where it is so you’d have to do some of your own research here. But sensors can usually be checked with a multimeter for proper resistance at a given temperature. If the sensor is bad then replace it. If it’s good then you have an issue elsewhere whether it’s in the gauge or wiring. I doubt it’s wiring because if it is wiring then your temp needle will likely always indicate cold.
Second, I’d flush the system. Let a shop do it so they can use a machine and cycle fluid through. This will not only get air out but will also get any sludge or junk out of the coolant passages.
After this is done, run the engine at idle in your driveway till it warms up and verify the fan turns on.
If after all this you still have issues, you may have a bad water pump or some other issue. I say to do this “if it were me” because some people have their own methods of troubleshooting. But this is just mine.
It’s important to document details of what’s happening. What was the temp outside when your engine did this. Where did the steam come from? When your engine lost power, was there any noises? Every detail matters so pay close attention to everything.
First, check your temp sensor. I have no clue where it is so you’d have to do some of your own research here. But sensors can usually be checked with a multimeter for proper resistance at a given temperature. If the sensor is bad then replace it. If it’s good then you have an issue elsewhere whether it’s in the gauge or wiring. I doubt it’s wiring because if it is wiring then your temp needle will likely always indicate cold.
Second, I’d flush the system. Let a shop do it so they can use a machine and cycle fluid through. This will not only get air out but will also get any sludge or junk out of the coolant passages.
After this is done, run the engine at idle in your driveway till it warms up and verify the fan turns on.
If after all this you still have issues, you may have a bad water pump or some other issue. I say to do this “if it were me” because some people have their own methods of troubleshooting. But this is just mine.
It’s important to document details of what’s happening. What was the temp outside when your engine did this. Where did the steam come from? When your engine lost power, was there any noises? Every detail matters so pay close attention to everything.
07-05-2021, 09:57 AM
#7
Super Moderator
Did you open the hood and see where the steam came from? That’s what I mean about the details. Did the steam come from the radiator cap, engine coolant hose, between the engine heads and case? When you do as I stated above, spray some engine cleaner in the engine bay and wash it clean. This will help you determine where the new mess is when/if it happens again.
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user 729872082 (07-06-2021)