Overheating issues 2023 JL

[UncleJimmy]

This is super useful for me! Thank you! My 2020 JLUR blew a radiator in 2022 doing high way speeds up a steep mountain pass in the desert while blasting the A.C (it was so hot we were dying!). I had a very heavy Yeti cooler and camping gear in with me. I was on 35’s with a 2.5 lift in a 3.6. What shocked me most is my temp gauge never moved! I could smell the coolant and became concerned but my gauge was green until it just suddenly wasn’t! By Then I was blowing smoke and spewing rad fluid on a desert mountain with my 4 year old without cell service! I didn’t even hear the fan come on! I’m not convinced it did! It was covered under warranty but ever since when I’m wheeling hard or idling for a while I can start to smell that smell an engine makes when it’s getting hot and I don’t always hear the fan come on. Chrysler told me they checked the fan and thermostat and it was fine. People tell me it’s all in my head and it’s my fault for running the AC climbing a steep mountain while hauling camping gear ?‍. But we are talking about a brand new vehicle with very little miles. So what’s really happening? To be honest I don’t trust that temp gauge or the fan and I’ve been on a journey to find a way of assisting in keeping the rad cool.

I just started using the cooldown function on the Tazer, turns the fan on full and I keep the oil temp up on the gauge all the time now. I hit it on before steep mountains or crawling off road or stop and go if it's long enough. (I put in a feature request for some additional cooling features to be more like the RPM but with user set temp values so I can customize the values exactly where I want.) This weekend went up a long 10 min grade gain about 3000 ft with probably extra 600-800 lbs payload in the Jeep, kept the speed at 65 mph and hit the cooldown function before I went up the hill and hit the top at maybe at 206 F, so worked great. Personally, I think the fan values are set way too high before the fan kicks on. I suspect it's CAFE related as they seem to make a lot of compromises for fuel economy. And yes, I know it's electrical fan, but the alternator has to run more and that costs horsepower which equals fuel. Same logic as going with light grade motor oil to save a .5 percent mpg. So, bottom line, keep the oil temp up on the gauge cluster, and get a Tazer or RPM to kick the fan on and it helps to anticipate the climbs.

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[mwilk012]

This is super useful for me! Thank you! My 2020 JLUR blew a radiator in 2022 doing high way speeds up a steep mountain pass in the desert while blasting the A.C (it was so hot we were dying!). I had a very heavy Yeti cooler and camping gear in with me. I was on 35’s with a 2.5 lift in a 3.6. What shocked me most is my temp gauge never moved! I could smell the coolant and became concerned but my gauge was green until it just suddenly wasn’t! By Then I was blowing smoke and spewing rad fluid on a desert mountain with my 4 year old without cell service! I didn’t even hear the fan come on! I’m not convinced it did! It was covered under warranty but ever since when I’m wheeling hard or idling for a while I can start to smell that smell an engine makes when it’s getting hot and I don’t always hear the fan come on. Chrysler told me they checked the fan and thermostat and it was fine. People tell me it’s all in my head and it’s my fault for running the AC climbing a steep mountain while hauling camping gear ?‍. But we are talking about a brand new vehicle with very little miles. So what’s really happening? To be honest I don’t trust that temp gauge or the fan and I’ve been on a journey to find a way of assisting in keeping the rad cool.

What’s really happening is that the OEM radiator is a piece of junk, every JL I have seen with a coolant leak is leaking from the exact same spot on the upper drivers side of the radiator.

A major oversight of nearly all cooling systems in modern vehicles is their inability to detect a loss of coolant. Once coolant is low, air and steam bubbles cause flow instabilities, and the coolant temperature sensor no longer provides an accurate indication of core temperature.

 

[Willys41]

This is super useful for me! Thank you! My 2020 JLUR blew a radiator in 2022 doing high way speeds up a steep mountain pass in the desert while blasting the A.C (it was so hot we were dying!). I had a very heavy Yeti cooler and camping gear in with me. I was on 35’s with a 2.5 lift in a 3.6. What shocked me most is my temp gauge never moved! I could smell the coolant and became concerned but my gauge was green until it just suddenly wasn’t! By Then I was blowing smoke and spewing rad fluid on a desert mountain with my 4 year old without cell service! I didn’t even hear the fan come on! I’m not convinced it did! It was covered under warranty but ever since when I’m wheeling hard or idling for a while I can start to smell that smell an engine makes when it’s getting hot and I don’t always hear the fan come on. Chrysler told me they checked the fan and thermostat and it was fine. People tell me it’s all in my head and it’s my fault for running the AC climbing a steep mountain while hauling camping gear ?‍. But we are talking about a brand new vehicle with very little miles. So what’s really happening? To be honest I don’t trust that temp gauge or the fan and I’ve been on a journey to find a way of assisting in keeping the rad cool.

I am not sure what dash cluster you have and if both clusters can show a digital coolant and oil temps.
I have the 7'' cluster or Rubicon cluster and can monitor the coolant and oil temps via the dash cluster.
Also you can monitor your temps in the off road page on the 8.4 radio
If you don't have the 7'' cluster or the 8.4 radio they can be added and it will give you a picture of your exact temps
Others can chime in here and let us know if the smaller clusters and radios have the ability

 

[Willys41]

What’s really happening is that the OEM radiator is a piece of junk, every JL I have seen with a coolant leak is leaking from the exact same spot on the upper drivers side of the radiator.

A major oversight of nearly all cooling systems in modern vehicles is their inability to detect a loss of coolant. Once coolant is low, air and steam bubbles cause flow instabilities, and the coolant temperature sensor no longer provides an accurate indication of core temperature.

You are correct
For months I could smell coolant put could not find a leak and never lost coolant
After installing the Mishimoto radiator NO more coolant smells however it did not lower my high coolant temps and that was my real goal

 

[HeavyMetalFox]

I am not sure what dash cluster you have and if both clusters can show a digital coolant and oil temps.
I have the 7'' cluster or Rubicon cluster and can monitor the coolant and oil temps via the dash cluster.
Also you can monitor your temps in the off road page on the 8.4 radio
If you don't have the 7'' cluster or the 8.4 radio they can be added and it will give you a picture of your exact temps
Others can chime in here and let us know if the smaller clusters and radios have the ability

I do have that ability. Now that this episode has occurred to me I will be putting those temps on my screen on hot days with steep inclines to monitor them manually. Honestly thought I’d much rather find a way to aid keep the rad cool to avoid these situations rather than having to pull over for 30 mins on a hot highway to let it cool when I have a kid in the vehicle

 

[HeavyMetalFox]

What’s really happening is that the OEM radiator is a piece of junk, every JL I have seen with a coolant leak is leaking from the exact same spot on the upper drivers side of the radiator.

A major oversight of nearly all cooling systems in modern vehicles is their inability to detect a loss of coolant. Once coolant is low, air and steam bubbles cause flow instabilities, and the coolant temperature sensor no longer provides an accurate indication of core temperature.

so would the fix be to swap this out with an aluminum rad? Mishimoto (not currently available for the Jl but I’m on their wait list). When I’ve told people I plan to do this the immediate response is that this is a bad idea for vehicles that flex went offloading. That Jeep designed the plastic and aluminum combined radiators to withstand the stresses on the vehicle.

 

[HeavyMetalFox]

I just started using the cooldown function on the Tazer, turns the fan on full and I keep the oil temp up on the gauge all the time now. I hit it on before steep mountains or crawling off road or stop and go if it's long enough. (I put in a feature request for some additional cooling features to be more like the RPM but with user set temp values so I can customize the values exactly where I want.) This weekend went up a long 10 min grade gain about 3000 ft with probably extra 600-800 lbs payload in the Jeep, kept the speed at 65 mph and hit the cooldown function before I went up the hill and hit the top at maybe at 206 F, so worked great. Personally, I think the fan values are set way too high before the fan kicks on. I suspect it's CAFE related as they seem to make a lot of compromises for fuel economy. And yes, I know it's electrical fan, but the alternator has to run more and that costs horsepower which equals fuel. Same logic as going with light grade motor oil to save a .5 percent mpg. So, bottom line, keep the oil temp up on the gauge cluster, and get a Tazer or RPM to kick the fan on and it helps to anticipate the climbs.

I have the OBD J-scan. I’ll check and see if it has the same function. Thanks

 

[stumblinhorse]

so would the fix be to swap this out with an aluminum rad? Mishimoto (not currently available for the Jl but I’m on their wait list). When I’ve told people I plan to do this the immediate response is that this is a bad idea for vehicles that flex went offloading. That Jeep designed the plastic and aluminum combined radiators to withstand the stresses on the vehicle.

Overheating has been an issue for 15 years for wranglers. Every 3.6 jk ran hot. I got rid of mine because of that. And I can tell you there is only 1 solution. The fan…. A radiator, lower thermostat, water wetter, etc nothing else works. Trust me. My 3.6 I invested $5k in trying to lower temps. The fan must run to keep it under 225°. If that is your goal, you only have that one choice. Don’t waste a penny on anything else. Nothing else works.

But understand 1 thing. Running your fan all the time makes them wear out faster and they should be replaced at least every other year. It needs to be tested every oil change at least. Always a trade off.

 

[mwilk012]

so would the fix be to swap this out with an aluminum rad? Mishimoto (not currently available for the Jl but I’m on their wait list). When I’ve told people I plan to do this the immediate response is that this is a bad idea for vehicles that flex went offloading. That Jeep designed the plastic and aluminum combined radiators to withstand the stresses on the vehicle.

There have been a lot of reports of cracked aluminum radiators here. The OE is probably still the best option for longevity, but it’s also crap.

 

[UncleJimmy]

For anyone interested, see Tazer fan feature request here:

https://www.jlwranglerforums.com/fo...ogramming-to-help-prevent-overheating.125710/

 

[Medsker]

I have the OBD J-scan. I’ll check and see if it has the same function.

It does but it's a little hard to find. It's under:

Modules, then Powertrain Control, then Activations, then Radiator Cooling Fan PWM Control State, then Choose Action, then On.

At least this is what I have written down. I hope it makes sense.

 

[racerdude90]

Has anyone here with the “vented hood” tried opening the vents up? Any noticeable change in average temps?
I’ve read some neat threads about how to open them up and keep water from getting in through the vents but haven’t decided to do it myself yet.

Just polling for more opinions on that as it seems relevant to this thread.

 

[BDinTX]

@racerdude90 I messed around a little bit to ensure air was exiting through the opened up vents instead of causing back pressure:

Under Hood Heat | Page 6 | Jeep Wrangler Forums (JL / JLU) -- Rubicon, 4xe, 392, Sahara, Sport - JLwranglerforums.com

This was on our first Jeep and but I did the same on my diesel almost as soon as I got it. I did NOT do any temperature testing before/after/etc. I do regularly notice the air above the vents shimmering, particularly when out wheeling where I'm idling alot or moving slow. That's also a pretty good indication heat is coming out.

 

[Willys41]

I do have that ability. Now that this episode has occurred to me I will be putting those temps on my screen on hot days with steep inclines to monitor them manually. Honestly thought I’d much rather find a way to aid keep the rad cool to avoid these situations rather than having to pull over for 30 mins on a hot highway to let it cool when I have a kid in the vehicle

RPM Extreme JL fan controller is the answer
http://www.rpmextreme.com/Product/311/Jeep-JL-PWM-FAN-CONTROLLER.aspx
I ordered mine with the high speed override
You can order it with ether positive or negative trigger
When you turn on the high speed override it will sound like a jet taking off

 

[stumblinhorse]

Has anyone here with the “vented hood” tried opening the vents up? Any noticeable change in average temps?
I’ve read some neat threads about how to open them up and keep water from getting in through the vents but haven’t decided to do it myself yet.

Just polling for more opinions on that as it seems relevant to this thread.

Yes, short of removing the hood it does not help.

Trust me when I say, the fan is the only reasonable thing to do to lower temps. I cut hoods, bought special hoods, snorkels, CAI direct piped to outside air. Special winch mounts to lower it. Lower temp Thermostats all the way to completely removing the guts of the t-stat. Nothing lowered it. Fan on all the time lowers it.

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