Hood louver thread to end all hood louver threads

Joined
Aug 13, 2019
Messages
27
Location
Arlington TX
I've seen many threads about these things and nothing with real experience and data; only a myriad of baseless one line opinions. I'd be happy for more opinions to supplement my little journey here. Bear in mind I'm not worried about looks as I have hacked many a thing from mine and have been happy with the results based on function. If you want these things for looks then just admit it and cut that sh*t up guys.

Down to the business,

I have a heat soak problem (as far as I can tell) and have since I bought it a few years ago. My cooling system appears to work like the day it was made and I maintain it whenever called for. The water pump, hoses, thermostat, and radiator have all needed replacement at some point within the last two years. I did the little tech bulletin from Jeep long ago and it did not help much on the trails here in Texas on hot days. I started pulling a little trailer recently and I have a mild issue on hot restarts and it misses for less than a minute or so before evening out at gas stops. I also notice the engine feels labored on city streets pulling the trailer from a stop once this occurs. This is not just an issue on the trail on hot days, it also manifests the issue after pulling the 1500lb trailer at interstate speed for a couple hours. My rig does appear to run quite well any other time. The temperature stays about 210 all the time as well. The issue does not present itself below 60 degrees or so with the trailer on the highway. Without the trailer and without trail use I never experience problems.

Last night I pulled the hood and then drove home a couple miles away leaving it at the shop (never been the no hood guy, so the looks were super entertaining). This morning was 40 degrees and on my way to get coffee and run a couple errands here in town before work the engine temp could never get to 210. The only difference was that the hood was removed because this has never happened before. It usually heats up and stabilizes very quickly. The old response of the hood makes no difference on operating temperature I may call into question. This isn't even a cold day really, but bear in mind I never got to a highway and it was perhaps idling and street driving for 20 minutes. I plan on installing the louvers and then seeing what happens afterward. I also ordered a set nice of insulators from Design Engineering to install at some point for the fuel rail and injectors. I have plenty of 70 degree days between now and actual cold weather so I hope I can get adequate results before waiting for late spring months.

What I want to see is this:
Does the heat soak issue dissipate under trailer load? (has presented itself at ambient temps in the 70 degree range)
Does it dissipate under trail load? (may be next year before I know this one)
If not, does the extra insulation help?

I haven't really ever done a long thread before, but for as many times as I have tried to find something other than opinion on the subject I think this might help others who run into this type of problem. Either it helps or it doesn't. Questions, comments, and flaming is all welcomed.

TLDR
Jeep sucks with (presumably) heat soak, gonna try to fix it, cutoff wheels solve everything.

20211119_074722.jpg


20211119_074810.jpg
 
  • Like
Reactions: TJ Starting
I've seen many threads about these things and nothing with real experience and data; only a myriad of baseless one line opinions. I'd be happy for more opinions to supplement my little journey here. Bear in mind I'm not worried about looks as I have hacked many a thing from mine and have been happy with the results based on function. If you want these things for looks then just admit it and cut that sh*t up guys.

Down to the business,

I have a heat soak problem (as far as I can tell) and have since I bought it a few years ago. My cooling system appears to work like the day it was made and I maintain it whenever called for. The water pump, hoses, thermostat, and radiator have all needed replacement at some point within the last two years. I did the little tech bulletin from Jeep long ago and it did not help much on the trails here in Texas on hot days. I started pulling a little trailer recently and I have a mild issue on hot restarts and it misses for less than a minute or so before evening out at gas stops. I also notice the engine feels labored on city streets pulling the trailer from a stop once this occurs. This is not just an issue on the trail on hot days, it also manifests the issue after pulling the 1500lb trailer at interstate speed for a couple hours. My rig does appear to run quite well any other time. The temperature stays about 210 all the time as well. The issue does not present itself below 60 degrees or so with the trailer on the highway. Without the trailer and without trail use I never experience problems.

Last night I pulled the hood and then drove home a couple miles away leaving it at the shop (never been the no hood guy, so the looks were super entertaining). This morning was 40 degrees and on my way to get coffee and run a couple errands here in town before work the engine temp could never get to 210. The only difference was that the hood was removed because this has never happened before. It usually heats up and stabilizes very quickly. The old response of the hood makes no difference on operating temperature I may call into question. This isn't even a cold day really, but bear in mind I never got to a highway and it was perhaps idling and street driving for 20 minutes. I plan on installing the louvers and then seeing what happens afterward. I also ordered a set nice of insulators from Design Engineering to install at some point for the fuel rail and injectors. I have plenty of 70 degree days between now and actual cold weather so I hope I can get adequate results before waiting for late spring months.

What I want to see is this:
Does the heat soak issue dissipate under trailer load? (has presented itself at ambient temps in the 70 degree range)
Does it dissipate under trail load? (may be next year before I know this one)
If not, does the extra insulation help?

I haven't really ever done a long thread before, but for as many times as I have tried to find something other than opinion on the subject I think this might help others who run into this type of problem. Either it helps or it doesn't. Questions, comments, and flaming is all welcomed.

TLDR
Jeep sucks with (presumably) heat soak, gonna try to fix it, cutoff wheels solve everything.

View attachment 291392

View attachment 291393
You have a bad thermostat. Fix it and before you do, use a drive around flush to clean out the block.
 
I've seen many threads about these things and nothing with real experience and data; only a myriad of baseless one line opinions. I'd be happy for more opinions to supplement my little journey here. Bear in mind I'm not worried about looks as I have hacked many a thing from mine and have been happy with the results based on function. If you want these things for looks then just admit it and cut that sh*t up guys.

Down to the business,

I have a heat soak problem (as far as I can tell) and have since I bought it a few years ago. My cooling system appears to work like the day it was made and I maintain it whenever called for. The water pump, hoses, thermostat, and radiator have all needed replacement at some point within the last two years. I did the little tech bulletin from Jeep long ago and it did not help much on the trails here in Texas on hot days. I started pulling a little trailer recently and I have a mild issue on hot restarts and it misses for less than a minute or so before evening out at gas stops. I also notice the engine feels labored on city streets pulling the trailer from a stop once this occurs. This is not just an issue on the trail on hot days, it also manifests the issue after pulling the 1500lb trailer at interstate speed for a couple hours. My rig does appear to run quite well any other time. The temperature stays about 210 all the time as well. The issue does not present itself below 60 degrees or so with the trailer on the highway. Without the trailer and without trail use I never experience problems.

Last night I pulled the hood and then drove home a couple miles away leaving it at the shop (never been the no hood guy, so the looks were super entertaining). This morning was 40 degrees and on my way to get coffee and run a couple errands here in town before work the engine temp could never get to 210. The only difference was that the hood was removed because this has never happened before. It usually heats up and stabilizes very quickly. The old response of the hood makes no difference on operating temperature I may call into question. This isn't even a cold day really, but bear in mind I never got to a highway and it was perhaps idling and street driving for 20 minutes. I plan on installing the louvers and then seeing what happens afterward. I also ordered a set nice of insulators from Design Engineering to install at some point for the fuel rail and injectors. I have plenty of 70 degree days between now and actual cold weather so I hope I can get adequate results before waiting for late spring months.

What I want to see is this:
Does the heat soak issue dissipate under trailer load? (has presented itself at ambient temps in the 70 degree range)
Does it dissipate under trail load? (may be next year before I know this one)
If not, does the extra insulation help?

I haven't really ever done a long thread before, but for as many times as I have tried to find something other than opinion on the subject I think this might help others who run into this type of problem. Either it helps or it doesn't. Questions, comments, and flaming is all welcomed.

TLDR
Jeep sucks with (presumably) heat soak, gonna try to fix it, cutoff wheels solve everything.

View attachment 291392

View attachment 291393
I’ll trade you my hood with a louver installed for your windshield frame.
 
You have a bad thermostat. Fix it and before you do, use a drive around flush to clean out the block.

I will do a flush on the block and swap thermostats. Do you have a preferred brand that works best?

Also just to be clear, it never overheats in any other instance except the two I stated and even that I couldn't call overheated. No boiling coolant, no overflow from the reservoir, nothing to note extra expansion. Except... I've cracked two radiator tops in the last 6 months. I chocked it up to inferior parts.
You may want to consider adding a trans cooler, too, once you replace the t-stat.
I have a standard transmission.




I've also already cut the hood, so I'm committed.
 
I'm sticking to a 1 line opinion here. Hood louvres aren't the fix to your issue.
To keep this to 1 line, I agree with Blaine that your thermostat is likely bad or not a 195 degree model.

Technically that is 2 lines. 😀

My theory is that air flow through the radiator is not good at highway speeds. There are a few threads that discuss easy mods to increase air moving through the radiator. I'm a bit busy, but will look for some of the threads.
 
Technically that is 2 lines. 😀

My theory is that air flow through the radiator is not good at highway speeds. There are a few threads that discuss easy mods to increase air moving through the radiator. I'm a bit busy, but will look for some of the threads.
I try to keep my radiator and ac clean each time I wash. I would be open to ideas if you can identify the thread easily. I'll peruse the search function as well.
 
I will do a flush on the block and swap thermostats. Do you have a preferred brand that works best?

Also just to be clear, it never overheats in any other instance except the two I stated and even that I couldn't call overheated. No boiling coolant, no overflow from the reservoir, nothing to note extra expansion. Except... I've cracked two radiator tops in the last 6 months. I chocked it up to inferior parts.

I have a standard transmission.




I've also already cut the hood, so I'm committed.
Stant. I think a 45359 is what you want.
 
My theory is that air flow through the radiator is not good at highway speeds.
Only if it's clogged with dirt, mud, etc. And note too that flow is better through a 1 or 2 row radiator like TJs came with than it is through a 3 or 4 row radiator. And of course air flows better through a radiator at highway speeds than it does when at slow speeds.
 
  • Like
Reactions: rasband
I will do a flush on the block and swap thermostats. Do you have a preferred brand that works best?
I only use Mopar cooling system components. If you get one, drill a 1/8" hole next to the jiggler so it will bleed the air out of the system better. Hole goes at the 12 o'clock position.
 
Technically that is 2 lines. 😀

My theory is that air flow through the radiator is not good at highway speeds. There are a few threads that discuss easy mods to increase air moving through the radiator. I'm a bit busy, but will look for some of the threads.
How does running with the hood off increase air flow through the radiator?
 
Air coming through the 7 bars will be looking for the easiest path. It looks like the factory made a modest attempt to force air through the radiator. I did not find the thread I was looking for that really addressed airflow through the engine bay. Air going under the Jeep, especially a lifted Jeep, increases pressure in the engine bay. That increased pressure slows air coming through the radiator and other heat exchangers. Anything that lowers the pressure in the engine bay like a vented hood, undertray or fender vented behind the front wheel will lessen the need for a fan. Removing the hood and strapping to the roof is the go to for overheating engines on Road Kill TV. @Paulstanfill85 forcing air to go through the radiator might cure the overheating when pulling a trailer.

OIP.jpg


02d4f9a0ab02c6d4993002cfecc01d89.jpg


3fabf3b6d953759cd591eead7a3764fc.jpg
 
My 100% stock Mopar cooling system with the OE hood never overheats even when towing my trailer up long grades in the summer. You have a fixable problem and you don't need hood vents or non-OE parts to do it.
OP has already cut the hood!
We have very hot summer air temps in West Oz and it doesn't cause TJ overheating and I know its the same in parts of US, highway speed air is too hot for top down in Jan & Feb (our summer), its similar to Vegas when its over 100 and windy during the day.
 
  • Like
Reactions: TheBoogieman