dblack

Back in June, local dealership replaced my radiator because it was leaking. Jeep is a 2014 JKUR with 30k miles...

Left the dealership and drove it to Blue Ridge and noticed on some of the hills in the mountains coolant temps were getting up to about 235 before coming back down. Fast forward to now, 3 months later, and my max coolant temps have been slowly rising. I live in a pretty hilly neighborhood and that's usually where it happens, but I've seen them get as. high as 242 at their peak before going back down. I'd say the Jeep normally is in the 220s.

Took it to a different dealership to look at (original dealership had a 3-week backlog...) and they couldn't find anything wrong. Said they pressure tested it and didn't find any issues, and said that the water pump and thermostat were working fine.

Those coolant temps still seem like they are getting awfully high to me, pushing my needle to the last tick mark before the H, before coming back down.

Is this "normal" like the dealership says, could there be other issues going on? I never remember them getting this high before the radiator was replaced, but to be fair, I didn't watch the coolant temps either; however, I feel like I would have noticed the needle moving.

Mark Doiron

I don't have a 3.6, but a friend of mine does. And he closely monitors his coolant temp. And 220s is correct. But, let me ask you about a possible problem (which is what led him to watch his temp): Do you have anything in your grill openings? We've (my friend and I) have done extensive measurements with various things (getting ready for a trip we took into the Arctic last year) and learned that some of those products dramatically drive up coolant temp. Anything more than a wire (made of thin metal) mesh will. The cheap plastic devices most definitely do. If so, remove that and check again.

Also, you might check YouTube for videos on how to burp your radiator. If you have a bubble in the system, that can cause higher than normal readings.

Finally, and I'm not sure how this applies to the 3.6L since it has a variable speed fan: I just finished up my solar eclipse expedition and during the return I had higher than normal coolant temps. Turns out I had a leaky water pump, which caused a bubble. But, even with sufficient coolant and new water pump still had a problem. On the 3.8s there is a high speed fan relay mounted behind the driver's headlight. When doing my research someone was asking where it is on the 3.6 as if they knew it existed. It may not exist at all, or maybe it does and yours needs to be checked. Symptoms would be that engine runs normally most of the time. But, if it does get hot, the high speed doesn't kick in to cool it back down. On the 3.6s, there is no problem telling if your fan is at high speed--it's very noisy.

Hope something there helps you out.

dblack

Thanks for the reply. I do have a winch and an LED on the fairlead, but the winch was there prior to having the radiator replaced. The LED was not, but it sits lower than the top of the winch, so I assumed it wasn't making a difference, but maybe it is. I'll pull it and drive around and see what happens.

Mark Doiron

No, all of that should be fine. I was thinking more of those decorative grill guards ...

https://www.extremeterrain.com/black...J108543&intl=0

dblack

Oh yeah, none of that. Just the winch and LED.