Hood louver thread to end all hood louver threads

I'm curious, and maybe I missed it, but.... What ACTUAL, MEASURABLE temperatures are we chasing here? People call my shop all the time talking about how their vehicle is getting hot or overheating. They aren't stranded on the side of the road, and there are no real symptoms, but "the gauge is closer to hot than it normally is".

These days with today's fuels, 235* (for example) on a temperature gauge isn't really a concern.
 
nathanotis said:
I'm curious, and maybe I missed it, but.... What ACTUAL, MEASURABLE temperatures are we chasing here? People call my shop all the time talking about how their vehicle is getting hot or overheating. They aren't stranded on the side of the road, and there are no real symptoms, but "the gauge is closer to hot than it normally is".

These days with today's fuels, 235* (for example) on a temperature gauge isn't really a concern.
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Not getting up to operating temp and then struggling when pulling the trailer.
 
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nathanotis said:
I'm curious, and maybe I missed it, but.... What ACTUAL, MEASURABLE temperatures are we chasing here? People call my shop all the time talking about how their vehicle is getting hot or overheating. They aren't stranded on the side of the road, and there are no real symptoms, but "the gauge is closer to hot than it normally is".

These days with today's fuels, 235* (for example) on a temperature gauge isn't really a concern.
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210 or close is a typical/normal temperature for the TJ.
 
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mrblaine said:
There are two issues to deal with inside the block. One is scale and the other is rust. The Prestone 3 day drive around flush works great for scale, not so great for rust. We try that first and if that doesn't get it done, we use the Thermocure product.

Before you swap anything, do the flush, then make sure the AC condenser and radiator do not have any blocked fins.
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Definitely appears to be rust inside mine. I ordered the product.

I may comb my condenser fins as well.
20211121_134123.jpg

Jerry Bransford said:
Mopar. Not "OEM replacement", Mopar.
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Understood.
 
nathanotis said:
Yes. But people freak out when it get's to 225-235. I'm just saying that's not a cause for panic that I see so often.
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I dunno about freaking out but I'd wonder what was happening if I was seeing that unless, perhaps, I was pulling my trailer up a long steep grade on a hot day. Even then I'd consider that unusual.
 
Steel City 06 said:
Any idea how the control system works? PWM? Analog? That is interesting though. Might actually be an OEM SPAL fan.
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Adding an electric fan is not a high priority as my cooling has no issues. It has been a while since I looked into controlling a fan. It isn't too difficult to do with some of the OEM fan control boxes with a stand alone ECM. I have a GM and a Dodge fan control for my Mustang and ended up installing the Dodge controller. The GM seems to have issues with melting the connector and scared me away. The new OEM fans integrate the PWM controller saving some wiring and simplicity. I don't know how to get an Arduino programmed to drive the fan. I do have a MegaSquirt 1 laying around that I think I could use to run the fan.
 
Brianj5600 said:
Adding an electric fan is not a high priority as my cooling has no issues. It has been a while since I looked into controlling a fan. It isn't too difficult to do with some of the OEM fan control boxes with a stand alone ECM. I have a GM and a Dodge fan control for my Mustang and ended up installing the Dodge controller. The GM seems to have issues with melting the connector and scared me away. The new OEM fans integrate the PWM controller saving some wiring and simplicity. I don't know how to get an Arduino programmed to drive the fan. I do have a MegaSquirt 1 laying around that I think I could use to run the fan.
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Most OEM integrally controlled fans, including with the SPAL fans, accept a PWM to ground signal. Usually only requires 10mA or so. The SPAL aftermarket brushless fans accept a PWM to 12V signal, 10mA or less. The frequency isn’t important, generally around 100Hz is used.

The Arduino is easily capable of PWM; there’s even a single line of coding for it. However, it only supplies board voltage (5V IIRC), so you’ll need a fast switching transistor to boost that to 12V.

So to power an integrally controlled brushless fan, all you likely need is an Arduino, a transistor, and the fan itself. Zero relays are required.

The old style brushed fans, including the ones used on the 4.0 engines, required PWM to be amplified to the supply voltage. They used solid state relays to amplify the PCM PWM up to 12V and 60A. This is a relatively inefficient and rather finicky system, and they failed often.
 
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Brianj5600 said:
Adding an electric fan is not a high priority as my cooling has no issues. It has been a while since I looked into controlling a fan. It isn't too difficult to do with some of the OEM fan control boxes with a stand alone ECM. I have a GM and a Dodge fan control for my Mustang and ended up installing the Dodge controller. The GM seems to have issues with melting the connector and scared me away. The new OEM fans integrate the PWM controller saving some wiring and simplicity. I don't know how to get an Arduino programmed to drive the fan. I do have a MegaSquirt 1 laying around that I think I could use to run the fan.
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I run my Spal brushless using their integrated temp sensor / controller. It works very well and provides variable speed control. I gave some thought to integrating it into the hemi ecu - which I believe is certainly possible - but at the time I was solving a cooling issue and did not want to spend the effort. Just because I enjoy challenges such as that, I may go back at some point and try to integrate it to the ecu.

Edit: And if I ever make that attempt, I’ll definitely be reaching out to @Steel City 06…
 
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Unfortunately I have had zero improvement on my hot starting issue.

Last Saturday I pulled the trailer at 70mph for approximately 60 miles at an ambient temperature of approximately 70 degrees. My temperature gauge never passed the 210 mark and ran fine. I stopped at a gas station to see how it would react with the engine off for 15 minutes before restarting. The temp was showing a little over 210 ignition on and engine off from sitting without water flow and then after starting returned to 210.

It started and ran roughly for a minute or less. Felt like it had a bit of a miss and has a knock as it runs until smoothing out.

Without pulling the trailer this doesn't happen unless it is 95 degrees plus and stuck out on trails crawling around for hours. I have some heat shielding for the injectors and fuel rail lying around I may try, but it appears that a mopar radiator is the next step to eliminate the aftermarket oreillys radiator as the issue unless I have gathered the information wrong.

I don't mind an expensive aluminum radiator as an option if there is a good track record but it sounds like that it just doesn't exist from some thread searches.
 
A new radiator will not improve your hot start issue. If the cooling system is able to maintain 210 it's fine. Hot restart problems are usually a result of fuel system issues. Check your fuel pressure when it is running rough. Also make sure the factory fuel rail heat shield is installed.
 
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