Temperature Reading Question

[Alan SOBX]

Newish Jeep owner and apologies if this topic has been beaten up before—I searched and didn’t find a thread. Quick question about normal coolant, oil, and transmission temperatures. When I take my Jeep into the sand, all three rise quickly which is fine—I figure the engine is working harder. If I go into OffRoad+ with the different gearing (seem higher RPMs at lower speeds), my temperatures spike enough where I can feel the heat coming in through the rolled down windows. OR+ seems to really spike it. I ran 40+ mph on sand in just 4H without a heat spike but use the OR+ in deep sand so that I can lock my rear diff. The temps get up into the 230s.

Is that normal? How high is too high? At what point should I let it cool down?

SIDE NOTE: it is a bit irritating that I have to go through a work-around process to lock my rear diff in 4H when the ‘24 lets you do it with a flip of the switch. If I can hack around it, Jeep obviously could release me to do it with the ‘23.

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[ShadowsPapa]

Newish Jeep owner and apologies if this topic has been beaten up before—I searched and didn’t find a thread. Quick question about normal coolant, oil, and transmission temperatures. When I take my Jeep into the sand, all three rise quickly which is fine—I figure the engine is working harder. If I go into OffRoad+ with the different gearing (seem higher RPMs at lower speeds), my temperatures spike enough where I can feel the heat coming in through the rolled down windows. OR+ seems to really spike it. I ran 40+ mph on sand in just 4H without a heat spike but use the OR+ in deep sand so that I can lock my rear diff. The temps get up into the 230s.

Is that normal? How high is too high? At what point should I let it cool down?

SIDE NOTE: it is a bit irritating that I have to go through a work-around process to lock my rear diff in 4H when the ‘24 lets you do it with a flip of the switch. If I can hack around it, Jeep obviously could release me to do it with the ‘23.

Would be nice if you posted the actual transmission and oil temperatures you are seeing.
230 is high for coolant - not horrible, but getting up there.
230 for oil - not a big deal under heavy heavy load, try to keep the transmission temperatures down below that area.
If you run higher engine RPM the coolant temperatures may drop.

A lot depends on the ambient air temperature at the time. If it was 70 degrees, it should stay cool easily.
Elevation also matters - less air density at higher elevations means higher temperatures for the engine, etc.
My engine, transmission and oil temperatures don't all always follow together. I can see 215 coolant temperature and 195 oil temperature and 220 transmission temperature.

 

[Blade1668]

Temperatures that I have seen coolant 195-235 it dropped off after the hills are topped. Transmission up to 209 I think I've seen 205 or 209 but dropped back to 200. Oil temperature 195-240 but that's towing and it was 100°f last time driving I did see 235 Oil temperature still towing. The trip before in 100°f weather the oil life monitoring cut back oil life down substantially. To the equivalent of driving double the distance. IE: a 450 mile trip it calculated it as driving 900 miles or so. 9-11% oil life used.

 

[ShadowsPapa]

Temperatures that I have seen coolant 195-235 it dropped off after the hills are topped. Transmission up to 209 I think I've seen 205 or 209 but dropped back to 200. Oil temperature 195-240 but that's towing and it was 100°f last time driving I did see 235 Oil temperature still towing. The trip before in 100°f weather the oil life monitoring cut back oil life down substantially. To the equivalent of driving double the distance. IE: a 450 mile trip it calculated it as driving 900 miles or so. 9-11% oil life used.

Sounds exactly right. I noticed mine drops the oil life more when towing or heavy loads, but normal highway driving at moderate speeds the oil life goes on forever.
Your temperatures seem pretty normal to me under those conditions.
I haven't towed in extreme heat yet - it's only been in the mid-80s so far when I towed.
It's been mid-90s to 100 though much of the summer (when not towing, luckily)

 

[Lunentucker]

 

[Blade1668]

Sounds exactly right. I noticed mine drops the oil life more when towing or heavy loads, but normal highway driving at moderate speeds the oil life goes on forever.
Your temperatures seem pretty normal to me under those conditions.
I haven't towed in extreme heat yet - it's only been in the mid-80s so far.

Yeah it was a heck of a temperature change on that drive over 100°f pulling trailer. I actually went through the forum's threads looking for one on temperatures others had been tracking.
A side note*
In 2.5 years I've got to replace the trailer tires. Slicks, center and outside tread. From wear patterns the trailer is under loaded (3500 lbs axle) most of time, hauling around 2200 lbs probably some of it close to load rating. I'm sure I've towed it over 10k in last 2 years.

 

[Alan SOBX]

Would be nice if you posted the actual transmission and oil temperatures you are seeing.
230 is high for coolant - not horrible, but getting up there.
230 for oil - not a big deal under heavy heavy load, try to keep the transmission temperatures down below that area.
If you run higher engine RPM the coolant temperatures may drop.

A lot depends on the ambient air temperature at the time. If it was 70 degrees, it should stay cool easily.
Elevation also matters - less air density at higher elevations means higher temperatures for the engine, etc.
My engine, transmission and oil temperatures don't all always follow together. I can see 215 coolant temperature and 195 oil temperature and 220 transmission temperature.

I was thinking the same—needed numbers and changes. I couldn’t remember exactly so I didn’t want to just toss out numbers. They were 30 degrees higher than 2H on a road which makes sense with more air cooling the engine that is not working as hard. I have been taking my 82 year old father fishing so he is looking at fishing spots (sea level) and asking questions while I am dodging people and holes in the sand so there was a lot going on. LOL. I will save this thread and repost with exact temperature changes next time out. Looks like I am fine though. Just a ton of heat that I can actually feel venting off.

Thank you and others for experiences so far. .

 

[ShadowsPapa]

I was thinking the same—needed numbers and changes. I couldn’t remember exactly so I didn’t want to just toss out numbers. They were 30 degrees higher than 2H on a road which makes sense with more air cooling the engine that is not working as hard. I have been taking my 82 year old father fishing so he is looking at fishing spots (sea level) and asking questions while I am dodging people and holes in the sand so there was a lot going on. LOL. I will save this thread and repost with exact temperature changes next time out. Looks like I am fine though. Just a ton of heat that I can actually feel venting off.

Thank you and others for experiences so far. .

This is a guess, of course, but under load you are burning more fuel - which means more heat of course, but also more work for the catalytic converters. I wonder - and this is truly a wondering - if they run hotter while towing and being a high vehicle, that heated air from around the converters is part of what you feel?
It would make sense that the converters would kick out more heat- higher engine RPM, more load and fuel burned and so on.

 

[Rooster 2141]

Sounds exactly right. I noticed mine drops the oil life more when towing or heavy loads, but normal highway driving at moderate speeds the oil life goes on forever.
Your temperatures seem pretty normal to me under those conditions.
I haven't towed in extreme heat yet - it's only been in the mid-80s so far when I towed.
It's been mid-90s to 100 though much of the summer (when not towing, luckily)

I am cruising all of the temp related posts lately due to my recent experience. I pulled my 4800 ish Lb. travel trailer to the beach last week in 107 degree ambient temperature. Saw readings as high as Oil 230, Trans 225, Coolant ............... 251. The coolant temp ranged between 222-238 for the most part. I was not liking it. After making my destination I started researching. The Gladiator does not throw a warning or derate until 260 degrees in coolant temp. On the way home ambient air was 97 degrees and everything on the Jeep ran about 5 degrees cooler. About 4 hours into my trip I realized that if was going to blow a head gasket it already would have. Apparently the 3.6 can run hot. Not comfortable at those temps but I guess it is what it is.

 

[Alan SOBX]

I am cruising all of the temp related posts lately due to my recent experience. I pulled my 4800 ish Lb. travel trailer to the beach last week in 107 degree ambient temperature. Saw readings as high as Oil 230, Trans 225, Coolant ............... 251. The coolant temp ranged between 222-238 for the most part. I was not liking it. After making my destination I started researching. The Gladiator does not throw a warning or derate until 260 degrees in coolant temp. On the way home ambient air was 97 degrees and everything on the Jeep ran about 5 degrees cooler. About 4 hours into my trip I realized that if was going to blow a head gasket it already would have. Apparently the 3.6 can run hot. Not comfortable at those temps but I guess it is what it is.

Those were the temps I was running in deep sand, sea level, 86 degree day. I don’t remember my coolant getting that high but I was around 230-235 for all of them which was what worried me.

I guess I should have just asked, "At what temperature should I start to worry?” I guess that is all that really matters.

 

[Gvsukids]

Those were the temps I was running in deep sand, sea level, 86 degree day. I don’t remember my coolant getting that high but I was around 230-235 for all of them which was what worried me.

I guess I should have just asked, "At what temperature should I start to worry?” I guess that is all that really matters.

The fans will kick on if the temps get too high.

 

[willys 41]

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 two days of testing put my temps now run at idle all day long 188 to 192
Normal driving I see 192 to 195 and 199 to 205 under hard acceleration put comes down real fast
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

 

[willys 41]

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

 

[IPRoutes]

Running AC on Max will keep the engine and oil temps cooler as AC forces the fan to run throughout.

 

[willys 41]

Yap
That's How I new that the real problem was NO air flow through the radiator until the temps hit 221 and 231
The JL PWM FAN CONTROLLER salves that problem

On another note
I found out that the Maserati 3.0 V6 is the same motor as the jeep 3.6 put a smaller displacement
I also found that the Maserati's normal operating temperature is 195 to 200 degrees
Maserati also uses 5w40 oil
Just yesterday I changed the oil on my Willys to 5w40 Valvoline European and it seems to be quieter
Today I will do the same to my wife's Rubicon and see if it is quieter
If Maserati runs 5w40 in there motor it should be good for my 3.6

Link to motor comparison

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