2015 Rubicon Coolant Temperature

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Aso544

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Was driving my 2015 Rubicon and went to get my battery replaced as it was getting pretty weak. When I got there and popped my hood I noticed it was pretty dang hot under the hood. I looked at my temp gauge and it was pointed straight up in the normal area. Coolant was a hair above the max line but that may be my fault as I may have overfilled it a while back. I clicked through the menu and got the electronic temperature and at idle it was 204 with AC on. When I drove home the temperature moved between 215 and 224 with the AC on. This was on a 78 degree afternoon.

Does this seem high? I did a search but couldn’t really find a definitive answer on where these 3.6s run temperature wise.

Also....does the electric fan come on at 225 degrees? Is there a way to test the fan to ensure it’s working properly.

Thanks for any info and advice.
 
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why not put a slightly cooler thermostat in them? I did this on my 4.0 TJ and it worked well.. guys were saying not to but I did & it was perfect.. But the 4.0 was a 205 or something & I went down to 195 I believe. JK may already have a 195 in it.
 
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There was someone recently that was having issues like that and replaced the coolant sensor, it wasn't turning the cooling fan soon enough.
 
Aso544 said:
Was driving my 2015 Rubicon and went to get my battery replaced as it was getting pretty weak. When I got there and popped my hood I noticed it was pretty dang hot under the hood. I looked at my temp gauge and it was pointed straight up in the normal area. Coolant was a hair above the max line but that may be my fault as I may have overfilled it a while back. I clicked through the menu and got the electronic temperature and at idle it was 204 with AC on. When I drove home the temperature moved between 215 and 224 with the AC on. This was on a 78 degree afternoon.

Does this seem high? I did a search but couldn’t really find a definitive answer on where these 3.6s run temperature wise.

Also....does the electric fan come on at 225 degrees? Is there a way to test the fan to ensure it’s working properly.

Thanks for any info and advice.
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Couple things I should have mentioned, yours is newer than the write up, and your has an electronic temp, so you can see the exact temp.

What you describe seems normal. The electric fan is set normally to come on at 225. So, you hit 225, the fan hits high and will bring it down.

The reservoir is not an issue. If you fill it to full exactly when cool, then run the Jeep to operating temperature, the reservoir should expand and go up....maybe an inch or so.

If you're bored, you can run this experiment yourself from cold. I did it, and put 1" hash marks on my reservoir with a sharpee from low to full and a few above that,. Start it, let it just idle, keep feeling the top radiator hose. watch temp, at 195 the top hose should get hot, then watch and as it rises, the fan should come on and turn off and the temp go up and down. The reservoir should have gone up as it came up, and will take about an hour and fall down to starting point when it cools.

Do all of this with the AC OFF. Get a track record of what it does, 30 mins to an hour and have a few beers or whatever.

Then, turn the ac on when the fan is off....the fan should immediately come on. When the AC is on, the fan is on, all the time.

These electric fans are shit, they are not water tight believe it or not, so they get wet they will go out. If your fan doesn't act and do what is described, time for a new fan.
 
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