Are Vented Hoods a Good Idea?

[jav_eee]

You want longevity? In my mind opening the vents to allow hot air out after parking it will make the underwood plastics last longer. That’s why I opened mine. I don’t notice any difference in driving/idling temps.

Sponsored

 

[willys 41]

You want longevity? In my mind opening the vents to allow hot air out after parking it will make the underwood plastics last longer. That’s why I opened mine. I don’t notice any difference in driving/idling temps.

Are you looking at the idiot gauge on the dash cluster on the the real coolant temps in the off road page on the radio.
The graph on the dash cluster will not move between 188 to 235+

degrees.

 

[Rahkmalla]

it's a jeep... just run it without a hood like a 30s ratrod

 

[jav_eee]

Are you looking at the idiot gauge on the dash cluster on the the real coolant temps in the off road page on the radio.
The graph on the dash cluster will not move between 188 to 235+

degrees.

Looking at the digital number read out on the dash. Matches the off-road page gauge.

 

[MikeSalt]

I had a 2013AEV rubicon with the heat reduction hood and noticed a 25 degree temp difference compared to my buddies stock rubicon. Which worked well in the Florida heat.

 

[ATL_Rubi]

You guys want to really lower your engine and oil temps.
Install the RPM Extreme JL Fan controller.
I have his old version on my Willys witch Idles the fan at 15% fan speed keeping air moving through the engine compartment at all times. Running it for over a year now.
I have his new version on my Wife's Rubicon witch comes on at 195 at 15% fan speed and turns off at 190 degrees. In stalled last week.
I have seen a reduction of 25 degrees on both oil and coolant temps.
Jon can program the module any way you like.
Here is More info on how it works.
http://www.rpmextreme.com/Product/311/Jeep-JL-PWM-FAN-CONTROLLER.aspx

This has been a game changer and I will be happy to answer any question you may have.

Wish this worked on the 23s…

 

[Broccoli]

You guys want to really lower your engine and oil temps.
Install the RPM Extreme JL Fan controller.
I have his old version on my Willys witch Idles the fan at 15% fan speed keeping air moving through the engine compartment at all times. Running it for over a year now.
I have his new version on my Wife's Rubicon witch comes on at 195 at 15% fan speed and turns off at 190 degrees. In stalled last week.
I have seen a reduction of 25 degrees on both oil and coolant temps.
Jon can program the module any way you like.
Here is More info on how it works.
http://www.rpmextreme.com/Product/311/Jeep-JL-PWM-FAN-CONTROLLER.aspx

This has been a game changer and I will be happy to answer any question you may have.

Did you just call your wife a Rubicon witch?

 

[willys 41]

Did you just call your wife a Rubicon witch?

woops

 

[FatBaldandWheeling]

Thanks for the replies, everyone. There are a few points being touched on, which I think bear some more discussion:

Yes, they are engineered to stock spec to work as intended. However, I think anyone that's here has a modified rig that will probably demand a bit more of the engine and drivetrain. Additionally, the movement at lower speeds are the greater concern.

While I largely wheel in Colorado, it does mean that in some situations I'll be moving only a couple miles an hour with 2k revs on certain obstacles. The fan will produce some airflow and the thermostat will open up, but as others have mentioned, it can be too little, too late.

There is the additional problem of stress under load, especially with the aforementioned obstacle scenario, in which I might have 600 lbs in the bed with a camping setup. It's something I am trying to anticipate ahead of time in terms of venting heat.

And finally, there have been some touches on moisture getting into the hood. I'd like to know more about what hoods were being used in those cases, and where the moisture is getting to. Some areas of the engine bay (I imagine) are safer, while others with constant moisture contact can eventually, or even more quickly, spell disaster.

Thanks all! Keep up the discussion-- it's very informative! And I am looking forward to the experiment conclusion!

 

[willys 41]

Thanks for the replies, everyone. There are a few points being touched on, which I think bear some more discussion:

Yes, they are engineered to stock spec to work as intended. However, I think anyone that's here has a modified rig that will probably demand a bit more of the engine and drivetrain. Additionally, the movement at lower speeds are the greater concern.

While I largely wheel in Colorado, it does mean that in some situations I'll be moving only a couple miles an hour with 2k revs on certain obstacles. The fan will produce some airflow and the thermostat will open up, but as others have mentioned, it can be too little, too late.

There is the additional problem of stress under load, especially with the aforementioned obstacle scenario, in which I might have 600 lbs in the bed with a camping setup. It's something I am trying to anticipate ahead of time in terms of venting heat.

And finally, there have been some touches on moisture getting into the hood. I'd like to know more about what hoods were being used in those cases, and where the moisture is getting to. Some areas of the engine bay (I imagine) are safer, while others with constant moisture contact can eventually, or even more quickly, spell disaster.

Thanks all! Keep up the discussion-- it's very informative! And I am looking forward to the experiment conclusion!

One more thing.
A few years ago I read about someone testing with and without vents on a jeep.
His conclusion was there was very little to no difference in under hood temps.
Basted on his finding I decided not to do venting.

 

[PuddleJumper]

You are 100% correct.
I am highly modified and weigh in at 6400lb with 37 tires and that's with out vacation luggage.
I worked for 6 months trying to get control of the cooling system and reduce my high 235+ coolant temps.
The thermostat starts to open at 190 and is fully opened at about 212 degrees.
The rad. fan come on at 221 at about 15% fan speed and 75% fan speed at 231 degrees.
This is the problem. To little to late.
The RPM Extreme JL Fan controller solves this problem.
Here is the way your fan will operate with the fan controller.

195 degrees = 15%
199 degrees = 30%
205 degrees = 50%
212 degrees = 75%
218+ degrees = 100%

After a year I have yet to see my temps over 212 climbing 4000ft to 8000ft mountain pass.

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

I want so badly. But it doesn't work with the new post 22' model year ECUs.

 

[jav_eee]

I want so badly. But it doesn't work with the new post 22' model year ECUs.

I wonder what the difference between your 22 ECU and my 21 ECU is. Can’t be that much…

 

[PuddleJumper]

I wonder what the difference between your 22 ECU and my 21 ECU is. Can’t be that much…

old ECUs are GPEC 4s and have side cable hook ups. New ones are GPEC5s and have top hook ups, and are locked down. Currently they cannot be tuned or adjusted in anyway.

edit: my 22' and 23" don't seem to have cooling issues tho. The fan kicks on around 180F which is only 5 degrees higher than what the JL mod does. I just don't the percentage at which its running. But i have never had a over temp issue yet. Maybe GPEC5s are programmed more aggressively on the cooling.

 

[jav_eee]

old ECUs are GPEC 4s and have side cable hook ups. New ones are GPEC5s and have top hook ups, and are locked down. Currently they cannot be tuned or adjusted in anyway.

Mine has the GPEC5 with the connectors on top and I’m running the fan controller just fine…

 

[PuddleJumper]

Mine has the GPEC5 with the connectors on top and I’m running the fan controller just fine…

well there is some kind of difference. otherwise they wouldn't state any of that. And how would one know its working? and not just continuing to run on its stock profile? IS there a way to check that its actually running outside the stock set range? or do you have to get the switchable option and do it manually?

Sponsored