JK engine temp fluctuation

[jean05]

Hi all

Hope you can help, I have a 2016 4 door JK with 11k on. Today for the first time the temp went up to 112°c. That was when I saw it but it never went over the 3/4 mark. The temp came down to 97 and went up to 108 again. I did almost 300km motorway today and its 40°C outside. But this was the first time since I bought it new. And the coolent level looks good and cant find any other issues.
Is this normal?

Cheers
Jean

[Easy77]

Jean, with JK it is very normal, especially on a hot day. JK with 3.6 pentastar engine will run at 96-98 degrees with no load on it. If you drove up a hill in a bit too tall gear, it can easily climb to 110-ish. I would not worry too much, just keep an eye on it and on the coolant level. You could also try to listen to the thermo fans on the radiator - they should switch on hotter days. If temperature goes up again to 110 and you hear no fans blowing, then you have a problem... Hard to diagnose from my chair so if you notice these jumps in temperature for no apparent reason then try to talk to a professional mechanic.

[jean05]

All good. Hope its normal. The fan does go on like it should. I need to take it for its first service soon and will mention it to them.

[jean05]

Hi all
So I went out 4x4 this weekend and the temperature was not too bad. It went up to 112 at the most while climbing hills in low range.
So today I did a bit of longer distance driving on the tar. Not even 5km from my place I found that it did the same thing again. So I drove to the longest hill I could find in my area and the temp just went up 118°C but the hill was also to an end. The indicator went to just before 3/4.
The question I have is that why now after 5 months. Traffic driving its all good. It seems like it happens when the revs goes up. I am sure if that hill was 1km longer it would have gone in the red.
Water in radiator and in bottle is perfect.
I know that the pentastar engine run hot but this is sure not normal.
Any ideas?

Cheers

[Heidi]

does not sound normal - we have a 2013 jku it the needle barely budges.

[Elio S]

If the needle goes up while you are driving, it sounds like you have a water flow problem. Possible causes, dodgy thermostat, dodgy water pump or a blocked radiator. As it's still under manufacturers warranty, get it looked at. It might help if somebody takes a photo of the needle or if it goes up quickly, maybe a video, so you can show the guys at Jeep what is happening, because chances are it won't do it when it's at the dealership and they will turn around and say there is nothing wrong with it.

[Dave]

Or bite the bullet and accept (like I did with fluctuating temps in my old KJ) that Jeep will not be able to find the problem, and pay to have a specialist fix it. I had Natrad replace parts to fix the problems I had because Jeep couldn't...

[jean05]

So I also asked the same question on the USA wrangler forum. Its seems like its a common issue with the 3.6. About 80% of them made have this issue and its nothing to worry about, I it will bother me until its fixed. So I got one of them and it seems like mine must be one of the worse 3.6 engines made. So, by the looks of it, the only way to fix it is to get the fan to kick in sooner. It seems like this is what they have done in the states and it works. They use a tuner program called Hptuner. So the magic question is: Who can do this for me?

[Elio S]

So I also asked the same question on the USA wrangler forum. Its seems like its a common issue with the 3.6. About 80% of them made have this issue and its nothing to worry about, I it will bother me until its fixed. So I got one of them and it seems like mine must be one of the worse 3.6 engines made. So, by the looks of it, the only way to fix it is to get the fan to kick in sooner. It seems like this is what they have done in the states and it works. They use a tuner program called Hptuner. So the magic question is: Who can do this for me?

Speak to the guys at Hills 4x4. I'm sure they can or know somebody that would be able to do it

[DanD]

I have a 3.6 also and the radiator fan kicks in for me at 112 deg C - please report back if you get it sorted as I don't like seeing the high temps either...