Overheating issues 2023 JL

[Willys41]

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.

I read one time about a guy that did testing with and without the vents open
He saw very little to no change in under hood temps
The RPM Extreme JL fan controller will keep air moving in the engine compartment
I can now stand next to my jeep and feel the hot air on my legs

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[UncleJimmy]

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.

I agree as far as keeping engine temps in a good range, the fan has to be working and doing it's job. However, I will be opening the vents on my Rubicon hood as it does help with engine bay temps, for the battery, plastics, hoses etc. A fair amount of users result to opening the hood after shutting the engine off, so this would help in letting heat escape and creating a draft of cool air from the bottom, sides and front, although, like I said, it does not appear to effect engine temps per se.

Also, one my the features requests for the Tazer would be to add a user definable fan % and time (3-5 mins) for the fan to run after engine shut off to assist with cooling the engine bay.

https://www.jlwranglerforums.com/fo...help-prevent-overheating.125710/#post-2626683

 

[Willys41]

I agree as far as keeping engine temps in a good range, the fan has to be working and doing it's job. However, I will be opening the vents on my Rubicon hood as it does help with engine bay temps, for the battery, plastics, hoses etc. A fair amount of users result to opening the hood after shutting the engine off, so this would help in letting heat escape and creating a draft of cool air from the bottom, sides and front, although, like I said, it does not appear to effect engine temps per se.

Also, one my the features requests for the Tazer would be to add a user definable fan % and time (3-5 mins) for the fan to run after engine shut off to assist with cooling the engine bay.

https://www.jlwranglerforums.com/fo...help-prevent-overheating.125710/#post-2626683

I do agree with after shut down you will get convection cooling .
Heat rising and pulling in cooler air from underneath
The vents are the way to accomplice this

 

[HeavyMetalFox]

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.

And how do you make the fan run manually? With the tazer? Obd j scan?

 

[HeavyMetalFox]

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.

Thanks so much

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

whoa! Ok cool thanks. I’ll check this out

 

[SavannahAL]

This is the way the jeep Wrangler and Gladiator cooling system works
The thermostat starts to open at 190 degrees and is fully open at 212 degrees
The radiator fan comes on at about 15% fan speed at 221 and 75% at 231 degrees
This has been a ongoing concern with a lot of people with modified jeep with large tires low gearing and pulling heavy loads Like me
I tried a lot of different solution including grills / larger radiator / Large pusher fan without ANY results in lowering coolant temps
What I did discover is that the tight factory and Mishimoto core will NOT pass free flowing air and any speed. I got very little air to pass through the radiator with a large high volume high pressure fan mounted to the condenser. The air would hit the core and shoot out the gaps between the condenser and the rad. core
The only way is to suck air through the rad. core
6 month ago I came across the RPM Extreme JL fan controller. PROBLEM SOLVED
I now can run all day at 190 to 195. The highest temp I have seen pulling a long 10 mile hill was 212 degrees
Lower coolant temps
Lower oil temps
What supersized me was my oil catch can collects less the half the oil it did before the fan controller
I am open to answering any question you may have
Here is a link

http://www.rpmextreme.com/Product/311/Jeep-JL-PWM-FAN-CONTROLLER.aspx

That's good info.

My 2018 Wrangler JL 3.6 left me stranded on the side of the Interstate a half dozen times with actually overheating and steam coming out of the hood. Yet no warning light ever coming on.

It was in the Savannah, GA dealer almost every month for 30 months. I knew ever service writer by name and many of the techs. I spent a chunk of each year at the dealer, luckily I was retired.
I'd drink coffee all day, read magazines, talk to the salespeople. They never solved/fixed it but they did fixed all the other many, many items that failed on it.

A retired Ford service manager solved my overheating. Pin prick leaks in the head gasket. The engine needed at least an hour running before it started to get hot.

I further solved my problem by trading it in on a 2022 Wrangler EcoDiesel. Couldn't be happier.

 

[Ratbert]

With another approach to dealing with overheating, @TOTL Innovations posted details of cooling characteristics of their hood. https://www.jlwranglerforums.com/fo...-r-o-hood-performance-testing-results.125807/

 

[Willys41]

With another approach to dealing with overheating, @TOTL Innovations posted details of cooling characteristics of their hood. https://www.jlwranglerforums.com/fo...-r-o-hood-performance-testing-results.125807/

You may see lower under hood temps put it will do nothing to engine temps.
They are controlled by the cooling system.

 

[Ratbert]

You may see lower under hood temps put it will do nothing to engine temps.
They are controlled by the cooling system.

Doesn't being able to evacuate more air out of the engine compartment imply that the radiator should be able to ingest more air? That is, there's less restriction behind the radiator.

 

[Willys41]

Doesn't being able to evacuate more air out of the engine compartment imply that the radiator should be able to ingest more air? That is, there's less restriction behind the radiator.

You may think that driving down the road at 60 mph you are getting lots of free flowing air through the radiator put you are not
After mounting a large high flow and high pressure pusher fan on the condenser I could only get a very very small amount of air to pass through the rad. core. Could hardly feel air on the motor side
The air would go though the condenser hit the rad. core and shoot out the gaps between the condenser and rad. core. The rad. core is built to tight and the only way is to suck the air through with the factory rad. fan
That's where the RPM Extreme JL fan controller solves the high engine compartment / coolant and oil temps
As far as air moving though the engine compartment. The hole under side and fender wells are open for air movement

 

[TOTL Innovations]

You may see lower under hood temps put it will do nothing to engine temps.
They are controlled by the cooling system.

It will do nothing to get below the factory specified operation temperatures but that isnt what is causing issues. The issue is what to do when those temps exceed factory cooling capacity putting the Jeep into limp mode etc...

Anything to help get heat out of the engine bay and get cooler denser air into the engine will absolutely help in mitigating that issue.

 

[Willys41]

It will do nothing to get below the factory specified operation temperatures but that isnt what is causing issues. The issue is what to do when those temps exceed factory cooling capacity putting the Jeep into limp mode etc...

Anything to help get heat out of the engine bay and get cooler denser air into the engine will absolutely help in mitigating that issue.

You need to get air passing through the rad. core first

 

[UncleJimmy]

It will do nothing to get below the factory specified operation temperatures but that isnt what is causing issues. The issue is what to do when those temps exceed factory cooling capacity putting the Jeep into limp mode etc...

Anything to help get heat out of the engine bay and get cooler denser air into the engine will absolutely help in mitigating that issue.

More is more. The more cooling the better. The primary issue, however, is the fan doesn't turn on. Period. It does nothing until it's too late because the values are programmed too high temp threshold and too low of fan speed. If the fan was running sooner and at a higher rate (100%) then many overheating issues would be prevented. Anyone can test this themselves if they have a Tazer by a 2 button push (with latest firmware 1.2023 - rt button on left SW and lt button on right SW simultaneously). I did this test myself this past weekend with the 3.6 on an extended grade loaded heavy by precooling the engine with fan Cooldown mode on Tazer to get too 192 F before the climb, kept it at a reasonable speed of 65 mph, kept the fan on and temps only got to 206 F. What would be nice is if the Tazer would do this automatically, which is why I sent them a feature request for next update.

If someone is exceeding the cooling capacity of the Jeep then I think venting/forced air will help but the fan has to be on and the engine in a low temp before the climb.

I will be venting my hood for engine bay temps for low speed crawling and engine shutdown to improve longevity of the battery, plastic and hoses etc.

 

[Willys41]

I have no issues with venting the hood.
In some cases it can be beneficial allowing trapped hot air out however I will not lower coolant or oil temps.
James and I have shown that the jeep cooling system is capable of keeping the coolant and oil temps down by increasing air movement through the rad. core

 

[stumblinhorse]

Venting the hood is “cool” in the winter. On my 3.6 that I traded, on winter drives, at a stop it would look like man hole covers in cold cities. People would point as steam would come out. In the summer it has that mirage look as heat escapes. Make the cars in front wavy! As you look thru the hot air.

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