When to cool engine

[Nokones]

Today on the trail driving between 15-25 MPH my coolant Temp ran about 194-201 degrees and my oil temp ran about 210-219. On the freeway returning home at 75-80 MPH my coolant temp ran about 220-223 degrees and my oil temp ran about 221-232 degrees.

I think my Tranny Temp was about 195 degrees.

The air temp was 99-103 degrees.

I am using the Pennzoil Ultra Platinum 0W-20 oil and my oil pressure was about 32 PSI.

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[Ruger]

Today on the trail driving between 15-25 MPH my coolant Temp ran about 194-201 degrees and my oil temp ran about 210-219. On the freeway returning home at 75-80 MPH my coolant temp ran about 220-223 degrees and my oil temp ran about 221-232 degrees.

I think my Tranny Temp was about 195 degrees.

The air temp was 99-103 degrees.

I am using the Pennzoil Ultra Platinum 0W-20 oil and my oil pressure was about 32 PSI.

im in Scottsdale and running up/down the 101 last couple days i saw almost the exact same thing. '25 JLU 3.6l.

 

[PropDr]

A few weeks ago, I drove up the Noonday Trail in Oregon, outside temps around 90, 4 low.
All temps in the high 230s.
I installed the RPM fan controller and did a similar run yesterday, max temps for everything around 210; similar outside temps and AC keeping us cool.
That thing works.

 

[PropDr]

Not even close.

But it degrades your lubricants quickly.
If you change your lubricants often, like in race cars or UTVs with high performance engines, 240 is no problem.
But if you like to go a few thousand miles between oil changes, I'd keep it well below 240.
But that is just me.

 

[Nokones]

But it degrades your lubricants quickly.
If you change your lubricants often, like in race cars or UTVs with high performance engines, 240 is no problem.
But if you like to go a few thousand miles between oil changes, I'd keep it well below 240.
But that is just me.

Are you sure about that? Are you a professional subject matter expert or are just saying this without any expertise on the subject and read something to the contrary on this forum along with all the other forum self-claimed automotive and oil company experts?

The newer engines require oils with a certain API certification. In this case, Jeep only recommends the oils with the API Sunburst label because these oils were blended specifically for the newer engines not only for emissions, but to be compatible with the top tier fuel blends, higher engine temps, and the close tolerances.

The oils of yesteryear are not the same blends and no-way compatible with the newer engines and fuel blends, and if you notice, they will not have the API sunburst or donut certification symbols. Some oils have the API Donut symbol, but I believe those oils are for the more severe duty engines such as the diesels.

The newer oils were developed in collaboration with the automotive manufacture engineers, Oil Company Chemists, and the EPA Emission Regulators. The newer oils will not breakdown during the higher oil temps and that has been proven in the various oil analyses and there are numerous You Tube videos on that subject.

Do you really think that the automotive manufactures and the oil companies came together and conspired to let their products cause damage and actually say they won't?

As depicted in the 2023 Wrangler Owner's Manual.

 

[CopperMtnGuy]

on any of my trips to moab/sand hollow, I don't see over 222 for coolant or oil, 204 for tranny.

 

[CopperMtnGuy]

Today on the trail driving between 15-25 MPH my coolant Temp ran about 194-201 degrees and my oil temp ran about 210-219. On the freeway returning home at 75-80 MPH my coolant temp ran about 220-223 degrees and my oil temp ran about 221-232 degrees.

I think my Tranny Temp was about 195 degrees.

The air temp was 99-103 degrees.

I am using the Pennzoil Ultra Platinum 0W-20 oil and my oil pressure was about 32 PSI.

Mine mirrors this. same oil even!

 

[PropDr]

Are you sure about that? Are you a professional subject matter expert or are just saying this without any expertise on the subject and read something to the contrary on this forum along with all the other forum self-claimed automotive and oil company experts?

The newer engines require oils with a certain API certification. In this case, Jeep only recommends the oils with the API Sunburst label because these oils were blended specifically for the newer engines not only for emissions, but to be compatible with the top tier fuel blends, higher engine temps, and the close tolerances.

The oils of yesteryear are not the same blends and no-way compatible with the newer engines and fuel blends, and if you notice, they will not have the API sunburst or donut certification symbols. Some oils have the API Donut symbol, but I believe those oils are for the more severe duty engines such as the diesels.

The newer oils were developed in collaboration with the automotive manufacture engineers, Oil Company Chemists, and the EPA Emission Regulators. The newer oils will not breakdown during the higher oil temps and that has been proven in the various oil analyses and there are numerous You Tube videos on that subject.

Do you really think that the automotive manufactures and the oil companies came together and conspired to let their products cause damage and actually say they won't?

As depicted in the 2023 Wrangler Owner's Manual.

Does 40 years as a Field service Engineer working on Marine propulsion systems count?

 

[Nokones]

Does 40 years as a Field service Engineer working on Marine propulsion systems count?

Maybe maybe not. I am not the one to qualify or disqualify you as a SME on the discussed subject or even in your particular field.

 

[WillysMeow]

You may chose to run your jeep at 240 degrees. NOT ME.

• Normal Operating Range: 195°F to 230°F (90°C to 110°C) depending on the load, towing, or ambient outside temperature.
• Warning Sign: At 240°F (115°C), the cooling fans will run at maximum speed and the computer may start pulling engine power.
• Limp Mode: At 250°F (121°C), the dashboard will illuminate the red warning light, and limp mode will activate.

Agreed. Got tuned by Brad @bmp and in addition to much smoother and more powerful engine running, fans are now set to come on earlier and harder...engine coolant temp now stays 195-205 most the time, oil can get about 10-12' warmer. Before that, it was not uncommon to hit 220-244 coolant temps in normal daily driving!

 

[PropDr]

Maybe maybe not. I am not the one to qualify or disqualify you as a SME on the discussed subject or even in your particular field.

Well, I can guarantee you that that job made it a prime requirement knowing about lubricants and the influence of heat upon them.
And the requirements exceeded anything you would find in the automotive industry.
Now I'm done with you in the thread because you starting to annoy me, and, at my age, annoyances are detrimental to my health.

 

[Nokones]

Well, I can guarantee you that that job made it a prime requirement knowing about lubricants and the influence of heat upon them.
And the requirements exceeded anything you would find in the automotive industry.
Now I'm done with you in the thread because you starting to annoy me, and, at my age, annoyances are detrimental to my health.

I agree, it would be best for you to step away from the screen and keyboard for awhile for your health.

 

[alphawolff]

240 is like the absolute max under normal situations. The fan should be howling like a banshee at this speed. Anything over ~244 and it's overheating. If you're regularly hitting 240 something is wrong unless it's hell outside or you're doing some crazy wheeling situations

 

[ScotM]

Emissions and mileage at the expense of engine longevity. Higher engine temps , sorry not a fan.- yeah a pun . I don’t care what the manual or manufacturer says. Engineering is engineering, 240 is too high for a non disposable engine.

 

[Willys41]

240 is like the absolute max under normal situations. The fan should be howling like a banshee at this speed. Anything over ~244 and it's overheating. If you're regularly hitting 240 something is wrong unless it's hell outside or you're doing some crazy wheeling situations

The fan comes on at 15% fan speed at 221 degrees and 75% fan speed at 231 degrees. To little to late. So the fan is not howling. However with my RPM Extreme fan controller and the optional 100% fan speed override switch now it howling. There is a big difference between 75% and 100% fan speed. You will know when it is running at 100%. Before the fan controller and hitting 240 I never heard my fan hit 100% fan speed.

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