Sponsored

Heavy Duty Cooling

go0001

Member
First Name
Gerald
Joined
May 30, 2020
Threads
1
Messages
20
Reaction score
18
Location
NJ
Vehicle(s)
Gladiator Overland Sting Gray
Occupation
Technology
The max towing weights and max tongue weights for each Gladiator model for each transmission type are in the owners manual. In the 2021 manual, the table starts on pg 205 (screenshots below).
(In the 2020 manual the table is on pg. 263, but the 2020 manual doesn't have the Diesel engine listed).
It's a shame they don't also have the max payload for each model in the same table - that would be useful.

I was able to download the manual here:
https://www.manualslib.com/download/2011196/Jeep-Gladiator-2021.html
(be careful of downloading adware by mistake)

It's also on the mopar site, but I've not been successful so far getting the download to work: https://www.mopar.com/en-us/my-vehicle/owners-manual.html

Jeep Gladiator Heavy Duty Cooling 1621129126465

Jeep Gladiator Heavy Duty Cooling 1621129150752

Jeep Gladiator Heavy Duty Cooling 1621129180511

Jeep Gladiator Heavy Duty Cooling 1621129404628
Sponsored

 

willys 41

Well-Known Member
First Name
Larry Olund
Joined
Oct 12, 2022
Threads
1
Messages
247
Reaction score
187
Location
Pleasanton Ca.
Vehicle(s)
2020 Jeep Willys
Occupation
Machinist / Auto Technician
Here is what I discovered and what I am working on
This is how the cooling system works or not working
The thermostat opens at 190 degrees
The cooling fans comes on at 1/4 speed at 221 and will only go fulls speed at 231 degrees
I have been trying to get control of the cooling system by adding a pusher fan on the condenser put this is what I found
Most cars including the jeep JK the condenser is mounted 1/4 to 1/2 in. from the radiator
On the Jeep JL the condenser is about 1 1/2 in. away from the radiator
I can get the pusher fan to shoot air though the condenser at 150 MPH put as soon as it hit the radiator the air blows out the large gaps between the condenser and radiator and NO air going through the radiator
Next step was to close the caps between the condenser and radiator to force the air through the radiator
So now with the gaps closed off I have about 15% of the air going through the radiator and the rest of the air is blowing back though the condenser and trans cooler
Two things wrong here. The gap between the condenser is to large and the radiator WILL NOT allow free flowing air to pass through it whether you are pushing air at 150 mph with a fan or diving down the road at 60 /70 mph and that is why you see a 30 to 40 degree swing in the coolant temps. You would thing driving down the road you are getting air passing through the radiator put you are getting very little to none until the fan kicks in and sucking the air through the radiator
I ordered a Mishimoto radiator (back ordered) it looks to have a more open core that will allow more free flowing air to pass through
I will install the Mishimoto and see how it goes
And NO. The radiator is not plugged in any way inside or out side. The jeep did this from day one . New in 2020
The Engineers got this one wrong and they know it from what I have read
READ THIS
https://jalopnik.com/the-engineering-behind-the-jeep-gladiators-tow-rating-1833657453

UPDATE
The Mishimoto radiator made no difference in lowering the temperature
Step 2
Just installed the Rpmextreme JEEP JL PWM FAN CONTROLLER
This is a game changer . Here is how your fan will work with this device


Operation:

When the engine is running the PWM fan will run at a low Idle speed (15%).
When the module reads the engine temp it will command the fan to the desired %.

Fahrenheit

199 degrees = 30%

205 degrees = 50%

212 degrees = 75%

218+ degrees = 100%

Override inputs: These are optional inputs depending on if you ordered them.

These inputs will run the fan as long as the unit is powered up, the engine does not have to be running for these to work. You can use these in various ways.

Example:
When the ( VIOLET ) wire has 12 volts applied the fan will run at MAX speed.

I have only three days of testing put my temps now run 188 to 192 at idle all day long
Normal driving I see 192 to 195 and 199 to 205 under hard acceleration put comes down real fast
Also I notIced my oil temps are about 20 degrees lower mainly becouse the the engine is running cooler and now I have constant air movement over the oil cooler
This weekend I will be testing on a long up hill drive put I suspect of 215
I will keep you updated



info
Jon Schaefer RpmExtreme
205-631-8225 6774 Old Hwy 31N
Rpmextreme.com Gardendale, AL 35071


UPDATE
Just got back from a 60 mile round trip with up and down hills
One hill is about a mile long and fairly steep
Max temps on uphill clime WITH PWM module
Coolant 203
oil temp 206
Trans temp 195

Going down hill after 2 minutes
coolant temps 185
Oil temps 188
Trans temps 188 to 190

freeway driving 70 MPH
coolant temps 188 to 192
oil temps 188 to 190
trans temps 190 ( Note / The trans cooler I believe has a 190 degree thermostat so you will always see about 190 )

BEFORE the PWM module I would see going uphill
Coolants temp rise to 221 fans kick in at bout 15% and then if the hill was a long one go to 231 before the fan kicked in at about 75% . I have seen temps as high as 234
Oil temps would get as high as 225
Trans temps would hit 206

The JEEP JL PWM FAN CONTROLLER is a keeper
Now I need to add one to my wife's stock Rubicon
 
Last edited:

willys 41

Well-Known Member
First Name
Larry Olund
Joined
Oct 12, 2022
Threads
1
Messages
247
Reaction score
187
Location
Pleasanton Ca.
Vehicle(s)
2020 Jeep Willys
Occupation
Machinist / Auto Technician
UPDATE
Just got back from a 60 mile round trip with up and down hills
One hill is about a mile long and fairly steep
Max temps on uphill clime WITH PWM module
Coolant 203
oil temp 206
Trans temp 195

Going down hill after 2 minutes
coolant temps 185
Oil temps 188
Trans temps 188 to 190

freeway driving 70 MPH
coolant temps 188 to 192
oil temps 188 to 190
trans temps 190 ( Note / The trans cooler I believe has a 190 degree thermostat so you will always see about 190 )

BEFORE the PWM module I would see going uphill
Coolants temp rise to 221 fans kick in at bout 15% and then if the hill was a long one go to 231 before the fan kicked in at about 75% . I have seen temps as high as 234
Oil temps would get as high as 225
Trans temps would hit 206

The JEEP JL PWM FAN CONTROLLER is a keeper
Now I need to add one to my wife's stock Rubicon
 

willys 41

Well-Known Member
First Name
Larry Olund
Joined
Oct 12, 2022
Threads
1
Messages
247
Reaction score
187
Location
Pleasanton Ca.
Vehicle(s)
2020 Jeep Willys
Occupation
Machinist / Auto Technician
UPDATE
Just got back from a 60 mile round trip with up and down hills
One hill is about a mile long and fairly steep
Max temps on uphill clime WITH PWM module
Coolant 203
oil temp 206
Trans temp 195

Going down hill after 2 minutes
coolant temps 185
Oil temps 188
Trans temps 188 to 190

freeway driving 70 MPH
coolant temps 188 to 192
oil temps 188 to 190
trans temps 190 ( Note / The trans cooler I believe has a 190 degree thermostat so you will always see about 190 )

BEFORE the PWM module I would see going uphill
Coolants temp rise to 221 fans kick in at bout 15% and then if the hill was a long one go to 231 before the fan kicked in at about 75% . I have seen temps as high as 234
Oil temps would get as high as 225
Trans temps would hit 206

The JEEP JL PWM FAN CONTROLLER is a keeper
Now I need to add one to my wife's stock Rubicon
 

Sponsored

ShadowsPapa

Well-Known Member
First Name
Bill
Joined
Oct 12, 2019
Threads
178
Messages
29,091
Reaction score
34,572
Location
Runnells, Iowa
Vehicle(s)
'22 JTO, '23 JLU, '82 SX4, '73 P. Cardin Javelin
Occupation
Retired auto mechanic, frmr gov't ntwrk security admin
Vehicle Showcase
3
I see no points being made in all of that - what are the points?
I don't see that these trucks run hot when towing within their limits.

BEFORE the PWM module I would see going uphill
Coolants temp rise to 221 fans kick in at bout 15% and then if the hill was a long one go to 231 before the fan kicked in at about 75% . I have seen temps as high as 234
Oil temps would get as high as 225
Trans temps would hit 206
I see no problem here.
The oil is well below and trouble temperatures and transmission of 206 is cool, no problem.
What is the goal?

I have only three days of testing put my temps now run 188 to 192 at idle all day long
That's cool to me - I prefer to run in the 195 area on my vehicles. I don't like cold running engines - inefficient and will build up contaminates in the crank case.
If my cars or trucks run below 190 I put a hotter stat in.
 

willys 41

Well-Known Member
First Name
Larry Olund
Joined
Oct 12, 2022
Threads
1
Messages
247
Reaction score
187
Location
Pleasanton Ca.
Vehicle(s)
2020 Jeep Willys
Occupation
Machinist / Auto Technician
Obviously you have not been following the entire post and other post about high temps
Like me and other here have been seeing coolant temps as high a 240 and oil temps 230 or higher
Some going into limp mode
With are modified jeeps you need a modified cooling system
Jon at rpmextreme has made and programed a JEEP JL PWM FAN CONTROLLER
This is not new. This has been done to other cars/trucks and motorcycles
With the JEEP JL PWM FAN CONTROLLER I have lowered all my temps by as much as 30 degrees
You can wait until 231 degrees before your fan kicks in at just 75% fan speed. Not me
READ THIS
https://jalopnik.com/the-engineering-behind-the-jeep-gladiators-tow-rating-1833657453

It shows how jeep engineers had a hard time getting the Gladiator to stay cool under heavy loads
This apply to any Wrangler or Gladiator with heavy loads or modification such as large tires / gears / winches / camping gear / trailer
 

TheRealStreetcommander

Well-Known Member
Joined
Apr 13, 2023
Threads
4
Messages
184
Reaction score
323
Location
East Coast
Vehicle(s)
Gladiator
Occupation
None of your business.
That Jalopnik article is complete propaganda. Unless they completely misquoted the statements of this alleged lead thermal management engineer, I don’t believe he’s an actual engineer of any consequence on the Gladiator product.

I agree with ShadowsPappa and Ecidiego on this one.

Your fan staging strategy can buy you a few seconds of reserve cooling capacity and nothing more. That futile gain may have been at severe consequence to reliabilty, durability, and fuel economy.

You have not increased the maximum cooling capacity of your Gladiator at all.

I applaud your efforts. You’ll need to add either efficiency or surface area to the actual heat rejection surfaces at the actual design conditions.
 

Sponsored

willys 41

Well-Known Member
First Name
Larry Olund
Joined
Oct 12, 2022
Threads
1
Messages
247
Reaction score
187
Location
Pleasanton Ca.
Vehicle(s)
2020 Jeep Willys
Occupation
Machinist / Auto Technician
I am sorry. But you are wrong
Free flowing air will not pass through the radiator by ether trying to push it through with a 150 mph wind speed fan or driving down the road at 70 mph. Meaning very little heat transfer. I have proved this
Air will ALWAYS take the path of least resistance and in this case it shoots out the 1.5 in. gaps between the condenser and the radiator. If you don't believe my test results. Prove me wrong. Do your own testing
In most cases the factory radiator is efficient in keeping the motor cool as long as you have enough air passing through it. And we don't until the fan kicks in a 221 degrees at 15% fan speed and 231 at 75% fan speed. To little air to late
Here are MY test results by moving air though the radiator / heat exchanger with and without the JEEP JL PWM FAN CONTROLLER

BEFORE the PWM module I would see going uphill
Coolants temp rise to 221 fans kick in at bout 15% and then if the hill was a long one go to 231 before the fan kicked in at about 75% . I have seen temps as high as 234
Oil temps would get as high as 225
Trans temps would hit 206
I would also see coolant temps around town hit 221 to 225 every day all day

WITH PWM module Max temps on uphill clime
Coolant 203
oil temp 206
Trans temp 195
Around town temps stay at 188 to 192 all day every day
 

ShadowsPapa

Well-Known Member
First Name
Bill
Joined
Oct 12, 2019
Threads
178
Messages
29,091
Reaction score
34,572
Location
Runnells, Iowa
Vehicle(s)
'22 JTO, '23 JLU, '82 SX4, '73 P. Cardin Javelin
Occupation
Retired auto mechanic, frmr gov't ntwrk security admin
Vehicle Showcase
3
Around town temps stay at 188 to 192 all day every day
Too cold.
Give me temps of at least 195-205.

Obviously you have not been following the entire post and other post about high temps
Like me and other here have been seeing coolant temps as high a 240 and oil temps 230 or higher
Some going into limp mode
With are modified jeeps you need a modified cooling system
Jon at rpmextreme has made and programed a JEEP JL PWM FAN CONTROLLER
This is not new. This has been done to other cars/trucks and motorcycles
With the JEEP JL PWM FAN CONTROLLER I have lowered all my temps by as much as 30 degrees
You can wait until 231 degrees before your fan kicks in at just 75% fan speed
Those "heavy loads" you are talking about are almost always outside of the engineering criteria - they needed to keep things working under the advertised ratings. That means towing loads, payload, etc. - and these will do that. Those putting on bigger tires, weighing the truck down with gear, exceeding posted payloads and towing abilities - the solution is to stay withing the engineering design of the truck. That's a big "DUH". Those who tow with these, GAS engines, and stick to the safe margins below the ratings don't normally see trouble.
I frankly don't sweat oil temperatures of 230. I don't like seeing 240 for coolant, but then I've never seen it that high. And for those who have - what the heck were they doing?

If Jeep saw a problem, the fix is easy since the fan is already there and all you are doing is speeding it up more quickly or at a lower threshold.
There's a give and take here, too - when you fire up that fan, you max out the alternator and take more HP from the engine, so you actually reduce the horsepower that can be applied to those big fat tires while towing maximum loads at extreme elevations.
If you are pulling that sort of load, you frankly bought the wrong damned truck.

I did the math a while back when people started swapping out the fans, checking their high current fuses and so on - and yes, you are loading up that alternator, putting more load on an already hard-working engine, which means that engine puts out even more BTUs.
The energy to spin the fan isn't free. It must come from the alternator.

When you modify your truck, you reduce your towing rating. Bigger tires - you've reduced the tow rating. Lift - you've reduced tow rating, more weight on the truck - skid plates, other armor, you've reduced your tow rating and yet some seem to believe that no, they can do whatever they want and keep the same payload and tow rating. Nope.
So what you are doing is fixing your own mistakes. you want to haul the same payload and tow the same trailer with those mods and that's not how it works.
You said it yourself "with our modified Jeeps" (corrected the word are to our for you) - your modified Jeeps are towing and hauling way over ratings because they ARE modified.
You want your cake, icing, ice cream and all served up to you.
Once you modify that Jeep - it's no longer rated to tow or haul what the book or door jamb sticker says. You've just unengineered it.

Jeep got it right - a stock JT towing within the limits will have no problem.
Any modifications to suspension or weight of the vehicle, including tires, lifts and so on, LOWER your payload and tow ratings - so you aren't really trying to fix anything Jeep did, you are trying to put a bandaid on what you've done to your Jeep.
 

willys 41

Well-Known Member
First Name
Larry Olund
Joined
Oct 12, 2022
Threads
1
Messages
247
Reaction score
187
Location
Pleasanton Ca.
Vehicle(s)
2020 Jeep Willys
Occupation
Machinist / Auto Technician
Nope
It was the engineers that added the larger fan and fan motor alternator and Z fuse in an attempt to bring down the coolant temps
Why do plains crash / air bags kill people and all the safety recalls . ITS BECAUSE ENGINEERS GOT IT WRONG
I am done disusing this
You have seen my results and I am very happy with them
Until you do your own testing and prove me wrong we are done
 

ShadowsPapa

Well-Known Member
First Name
Bill
Joined
Oct 12, 2019
Threads
178
Messages
29,091
Reaction score
34,572
Location
Runnells, Iowa
Vehicle(s)
'22 JTO, '23 JLU, '82 SX4, '73 P. Cardin Javelin
Occupation
Retired auto mechanic, frmr gov't ntwrk security admin
Vehicle Showcase
3
Around town temps stay at 188 to 192 all day every day
LOL - talk, or rather brag in a way, like that's a good thing. It's not really when you start building up acids and moisture in the crankcase because it doesn't get hot enough.

It was the engineers that added the larger fan and fan motor alternator and Z fuse in an attempt to bring down the coolant temps
The larger fan gives the ability to run it slower at lower speed or capacity most of the time. It's not so they could run it maxed out most of the time or even very often.

Why do plains crash / air bags kill people and all the safety recalls . ITS BECAUSE ENGINEERS GOT IT WRONG
Plains don't crash unless it's a sink hole. Planes do.
And they crash most often due to human error or conditions that no one could plan for or that exceed the capacity or ability of the aircraft.
Rare are the crashes due to engineering failure. But that's way beyond truck engine cooling.

Engineers did all they could within the confines of time and other design issues, and certifications already run. (if you look at the numbers below - looks to me like they nailed it! It pretty much runs in normal ranges)

Any change to the fans must be accounted for and reported to the EPA as part of the evaporative emissions guidelines. They must state the size, air flow and location of that fan and report it annually. Any change - has to be documented and reported. So maybe it's an EPA thing as much as anything else, eh? (YES, I am talking engine cooling fans - I have some of the reports - location, orientation, etc. has to be reported)

Of course, I go back to - we are in the general topics area, not diesel specific. You don't see "a lot of" complaints about the gas engine running too hot when running within the original design parameters of the truck itself. So I see this as a solution looking for a problem.
Show me the long long list of people with gas powered Gladiators towing within the limits set forth by the book, following all guidelines for frontage area, weight, tongue weight, payload, etc. who are having massive over-heating troubles.
220 coolant, 230 transmission and 230 oil isn't a massive over-heating problem. Look at the numbers below. Those numbers are FINE for a gasser and not at all "too hot".
My Comanche's 4.0 used to run in the 215 degree range all the time, It might run as cool as 200, and as high as 220, but it was never hot.
The colder you keep that engine, the more future troubles you can have. And "running around town as low as 188 all day every day" would have me changing my oil more frequently than if I was running coolant temperatures of 200-210 all day every day.

I wonder if people freak out because now they have the ability to actually see these temperatures when in the past it was a go/no-go type gauge. Green is ok, red is not ok.

This from a 1973 TSM (Technical Service Manual) - and consider this - they wanted the minimum engine operating temperature for a V8 to be 195:
195 stat (V8 engines) fully open at 218 degrees, open .003" within +/- 3 degrees of its rating.
A 205 degree stat was used on the 6 cyl engines (meaning a MINIMUM OPERATING TEMPERATURE of 205 degrees!!) should be fully open at 228 degrees.
Hmmmmm.
And I've been involved in instrument cluster and gauge work for decades. Take an engine temperature gauge from the 70s or 80s and guess what the range of that green normal band is......
bottom of normal is 185 - that ain't even warmed up yet (and you want 188?)
top of normal (but still just in the green) is 245 degrees.
Hot, when you leave the green band, is around 260 degrees.
So when I see an engine temperature of 220-230 I don't freak out. It's perfectly fine, normal, whatever.
No the engineers didn't screw up. A hot engine, within certain confines, is more efficient.
We get into heat rejection principal and other stuff if we go deeper.
(lower heat rejection = better)

But really, think about it - minimum temperature of 195 for a V8 and 205 for a 6 = perfectly normal. Those people that put in cold stats or drove short drives and never got 'er hot - slowly killing that poor engine.

Normal operating temperature for an LS V8? 210-220.
The Chevy people say -
Whatever coolant temp you have, you want oil temp at least 220 to boil off water and acids. Head temps can be 300 F. degrees without problems.
I guess they agree with me.

Ford people are saying 205-210 is normal.
Some Dodge people say 210 to 230 for engine coolant temps.

So why would anyone believe they need to run in the 190 area?

Most idiot light temp sensors trigger about 245 degrees. So for many decades, engineers from all sorts of companies have been saying they don't care until it hits 245 degrees.

Solution looking for a problem.
 
 



Top