There are many request what changes in temp were experienced. How do you measure under hood temp?
Anyone install hood vents?
- Thread starter 1TrackJack
- Start date
I don't know about the engine bay temps, but I do know that adding hood louvers decreased the intake temps about 10 degrees. This suggests that the intake plumbing that is exposed to the engine bay is not being heated as much when heat is able to escape through the hood.
Before my vents I needed gloves to open up the hood to use my onboard air.
With them, I don’t need gloves but it’s still pretty warm.
Engine seems to operate the same.
Before the cowl intake, I could cook food in the engine bay. After the cowl intake, a burrito takes a long time to barely warm up after leaving the gas station.
What change in engine bay temps would have significance? By which I mean it would improve performance or longevity in some meaningful/measurable way?
The factory wanted the thermostat to open at 195*, so we say get a 195 thermostat. Don't get a 180* or lower. Why do we say that? Becaus ewe want the engine running in the 200* range for optimal performance. What the heck is dropping the engine bay temps 10* going to do that is significant?
The factory wanted the thermostat to open at 195*, so we say get a 195 thermostat. Don't get a 180* or lower. Why do we say that? Becaus ewe want the engine running in the 200* range for optimal performance. What the heck is dropping the engine bay temps 10* going to do that is significant?
Heat degrades plastic and many other materials over time. Reducing heat exposure will help things to survive longer.
I thought of that, but how much longer with a 10* difference? What? 6 months? 5 years? 20 years? Who has any hard data? Seems like too many environmental factors (live in AZ vs MN, etc...)
How much more space proportionally does one have for heat release when they install some PS hood vents? GCherokee hood vents? Or God forbid but MotoBilt Fab 4 Wanna Be hood vents? I mean we're driving down the road and air is moving in and out of the engine bay (I assume). Water gets up in there so air must be going in there.
If the tradeoff is between being able to heat my trail lunch on the fuel rail or reducing intake air temp by ten degrees Ill go with a hot lunch every time.
No idea. There hasn't been much study in the off-road world of the long term effects of thermal degradation that I am aware of. All I know is that in both my previous and current careers, heat management was/is a concern in the interest of preservation and longevity. So, this is something I am aware of to consider.
If the plastic bits under the hood of my Jeep survive a few years longer before disintegrating because I did things ten years ago to reduce heat exposure, I will be anecdotally satisfied with my efforts.
Not burning my hand on the prop rod would be nice. I've never owned a vehicle that reaches the APPARENT high temps the TJ does.
For those who are worried about water getting on the engine from installing the hood vents the Motobilt version has drip trays similar to what was installed on the 1998 Grand Cherokee.
I know this is a JL hood but the drip pans are basically the same.
Genright used to sell some longer vents that weren't as wide but I looked and they don't seem to have them listed anymore on their website. But these are very similar to them
https://hoodlouvers.com/shop/side-l...IlisXduliE-nTFs4OhQj8-KY7YFYSxtEaAmdqEALw_wcB
I know this is a JL hood but the drip pans are basically the same.
Genright used to sell some longer vents that weren't as wide but I looked and they don't seem to have them listed anymore on their website. But these are very similar to them
https://hoodlouvers.com/shop/side-l...IlisXduliE-nTFs4OhQj8-KY7YFYSxtEaAmdqEALw_wcB
I installed the hood vents and where it made a big difference was heat soak. I have run the Jeep hard then sat for a bit and when I restarted it it ran horribly for a minute or less. This was due to fuel boiling in the rail but clears up once you run it. When driving I don’t really notice but when I stop and sit, then get back in the incab heat was where I noticed the difference. I do have a belly up I put on the Jeep that brings the cat up next to the floor. I originally did it without the body lift but installed a body lift which helped also.
As far as under hood heat, I worked for Ford for many years and then took a job down on the waterfront. When I got there I saw many issues with wiring harness and all plastic components under the hood due to heat. These vehicles idle for essentially 15 hours a day, the driving is under 15 mph traveling from location to location in the yard.
On the 05-06 I would think the IAT should be a decent indicator. I regularly see into the 180s in summer if I'm not moving.
At speed I wouldn't expect louvers to make much difference, but I can see it keeping the upper region of the engine compartment quite a bit cooler when idling or crawling. We all know hot air rises so giving it an opening in the direction it wants to go would definitely let the heat out. I don't doubt their effectiveness in underhood temps.
As to whether lower underhood temps provide any benefit is another matter. Someone with better understanding of the PCM programming could probably comment on what happens with lower IATs. I've seen the results of years of heat cycling on my 99 TJ - the harness loom and the vacuum line would crumble if I breathed on them. My 06 has crows feet all over the hood. Would either of those have still happened with hood vents? Don't know.
I'm not partial to the louvered sheet of steel screwed to the hood look. If I was ever to install some, it would have to look believable that it came that way from the factory, both from the top and bottom of the hood.
When I see non-factory louvers on a vehicle, I check the rear for a wing.
First, make sure the cooling system is operating properly.
Running a colder thermostat on a hot day does not make a bit of difference. It does make a huge difference on a cooler day. Your engine may not reach the proper operating temperature to burn off crankcase moisture.
Remove the cowl gasket during hot weather months. If rain is forecasted, it's a couple minutes to replace. If the hood bounces, buy a cheap replacement cowl gasket and cut 3 pieces about six inches long and space them out.
If underhood temps were an issue, sometime in the last 75 years, Jeep would have come up with a solution.
First, make sure the cooling system is operating properly.
Running a colder thermostat on a hot day does not make a bit of difference. It does make a huge difference on a cooler day. Your engine may not reach the proper operating temperature to burn off crankcase moisture.
Remove the cowl gasket during hot weather months. If rain is forecasted, it's a couple minutes to replace. If the hood bounces, buy a cheap replacement cowl gasket and cut 3 pieces about six inches long and space them out.
If underhood temps were an issue, sometime in the last 75 years, Jeep would have come up with a solution.
You might be OK with your underhood temps but some of us aren't. No one is claiming that installing vents will lower your operating temperature one bit. But what is being addressed is the sometimes higher tamps experienced under the hood.
I've got a V-8 in my TJ and my hood would be warm enough that I'd need to wear a glove to open the hood sometimes. I also had some plastic parts melt due to the heat. By installing the hood vents it allowed some of that heat to escape. Just like every other modification we all do to our Jeeps it's a personal choice. If you dislike them then by all means don't install any.
You mean like them ricers with the big fart can mufflers? Do you like mazda miatas?