Normal Operating Temperature

[Yaak392]

Hi all, I can't find the official operating temperature on my 2021 392. I thought it usually ran around 197 - 203. But as spring is coming the other day I saw 222. No check engine light. Radiator fan runs slow. Analog gage seems normal.
Ideas?

 

[Robr651]

Hi all, I can't find the official operating temperature on my 2021 392. I thought it usually ran around 197 - 203. But as spring is coming the other day I saw 222. No check engine light. Radiator fan runs slow. Analog gage seems normal.
Ideas?

Hopefully this thread is helpful to you:

Running Hot

Not sure if this is the right place to post this question, but I wanted to see what everyone is running for coolant temp? Usually, mine is sitting around 204-206 for everyday driving. But when I get it up to highway speeds (75-80), I notice the temp shoots up to around 225-230. Can this motor...

www.jeep392.com

 

[hardhat]

You are good. I was looking at that other thread and noticed with oil temps around 250 that the "analog" part of the gauge was still less that 1/2 so must be within specs in the minds of the people that made the gauges. Open offroad gauges and watch your engine coolant temp gauge next time you start the car and watch how quickly it warms up to just under the 1/2 mark. The one on the dash gets to its final resting place just under 1/2 way mark quickly and just sits there while coolant temp continues to rise. As bad as it sounds, I would worry more about the idiot lights if they went off than the number on the gauge. Mine normally runs around 200, but I have seen 230 on coolant temp. Airflow over radiator is main determinant of my coolant temp it seems. Driving it goes down and sitting goes up until fans kick on.

 

[Yaak392]

You are good. I was looking at that other thread and noticed with oil temps around 250 that the "analog" part of the gauge was still less that 1/2 so must be within specs in the minds of the people that made the gauges. Open offroad gauges and watch your engine coolant temp gauge next time you start the car and watch how quickly it warms up to just under the 1/2 mark. The one on the dash gets to its final resting place just under 1/2 way mark quickly and just sits there while coolant temp continues to rise. As bad as it sounds, I would worry more about the idiot lights if they went off than the number on the gauge. Mine normally runs around 200, but I have seen 230 on coolant temp. Airflow over radiator is main determinant of my coolant temp it seems. Driving it goes down and sitting goes up until fans kick on.

Thanks Hardhat, I guess I never paid attention to the digital readout as the analog gage was fine. So far we've got 13,000 miles of pure fun with this Jeep.

 

[hardhat]

21k here and has never missed a beat. Makes me grin every time I drive it. So ridiculous, so capable, so fun. Most enjoyable vehicle I’ve ever owned. Just glad they make them.

 

[Yaak392]

Hopefully this thread is helpful to you:

Running Hot

Not sure if this is the right place to post this question, but I wanted to see what everyone is running for coolant temp? Usually, mine is sitting around 204-206 for everyday driving. But when I get it up to highway speeds (75-80), I notice the temp shoots up to around 225-230. Can this motor...

www.jeep392.com

Just a follow-up
I pulled 228 degrees coolant temperatures and oil went to 248 degrees while going over a mountain pass. 45 degrees ambient temperature outside. Traveling 30 -40 mph. My dealership is now suggesting a sensor may be bad. (No check engine light) I used a Bluedriver scanner but had no indication of a problem.
Less than 500 miles on oil change.
Scheduled a inspection/repair in 3 weeks.

 

[Fast-n-Furious]

Just a follow-up
I pulled 228 degrees coolant temperatures and oil went to 248 degrees while going over a mountain pass. 45 degrees ambient temperature outside. Traveling 30 -40 mph. My dealership is now suggesting a sensor may be bad. (No check engine light) I used a Bluedriver scanner but had no indication of a problem.
Less than 500 miles on oil change.
Scheduled an inspection/repair in 3 weeks.

Even daily drive in the city and highway, mine goes over 220 coolant and 240 oil temp. I consider this normal.

 

[Yaak392]

Even daily drive in the city and highway, mine goes over 220 coolant and 240 oil temp. I consider this normal.

Maybe I'm wrong but I
don't think the 392 was designed to run this hot purposely. Also, my fan isn't coming on on full speed mode. I would rather be proved wrong than destroy that engine. I'll post more later.

 

[Fast-n-Furious]

Maybe I'm wrong but I
don't think the 392 was designed to run this hot purposely. Also, my fan isn't coming on on full speed mode. I would rather be proved wrong than destroy that engine. I'll post more later.

Normally they are not this high. I monitor the gauges constantly and they would go up like these numbers when I play around and have some fun on the road. How do you know about if the fan is running full speed or not?

 

[Earl 392]

Normally they are not this high. I monitor the gauges constantly and they would go up like these numbers when I play around and have some fun on the road. How do you know about if the fan is running full speed or not?

Earl runs about 212 per gage like others have stated about 1/2 way on dash gage.. on off road trips with our club the diesel engine seems to run the coolest by a few degrees then the 4cyl turbo again 208 210.. all very close they were running 38’s I was running 33’s .there is a lot of temp fluctuation

 

[stumblinhorse]

Normally they are not this high. I monitor the gauges constantly and they would go up like these numbers when I play around and have some fun on the road. How do you know about if the fan is running full speed or not?

I will tell you what I know. I have had a 3.6l, I now have a 6.4l and a 5.7l hemi vehicle and the coolant settings all work the same.
Coolant temps:
203* t-stat starts to open
206* t-start is fully open
226* fan start to run
235* fan on full
250* limp mode

A/C on will turn on the fan regardless of coolant temp.

All other temps will be related to coolant. But understand you want oil to be removing condensation so above 200*F is good. Oil with start “coking” at 300*F, that is bad…

 

[Fast-n-Furious]

I will tell you what I know. I have had a 3.6l, I now have a 6.4l and a 5.7l hemi vehicle and the coolant settings all work the same.
Coolant temps:
203* t-stat starts to open
206* t-start is fully open
226* fan start to run
235* fan on full
250* limp mode

A/C on will turn on the fan regardless of coolant temp.

All other temps will be related to coolant. But understand you want oil to be removing condensation so above 200*F is good. Oil with start “coking” at 300*F, that is bad…

Never knew about this, thanks for the insights!

 

[Yaak392]

Normally they are not this high. I monitor the gauges constantly and they would go up like these numbers when I play around and have some fun on the road. How do you know about if the fan is running full speed or not?

Just by the sound of the fan. It makes a lot more noise when spinning at hi speed.

 

[Fast-n-Furious]

Took a few pics today while I was driving normally with A/C in Auto mode. Mixed highway and local with frequent stops.

 

[stumblinhorse]

Looks normal to me… except my altitude is usually 8000 something

 

[LTZ470]

This shows a 195° Thermostat for Jeep 392...

Thermostat 195° 2022 Jeep 392

 

[stumblinhorse]

This shows a 195° Thermostat for Jeep 392...

Thermostat 195° 2022 Jeep 392

I think they make a 186° or 188° also. Only proven way to have an impact on high coolant temps is the fan low threshold. Not much can change that except for a programmer. As you can see in @Fast-n-Furious pics even at 206 when the t-stat is fully open the temperature is still climbing. All a lower t-stat is gonna do is throw a under temp MIL code in winter.

 

[LTZ470]

I think they make a 186° or 188° also. Only proven way to have an impact on high coolant temps is the fan low threshold. Not much can change that except for a programmer. As you can see in @Fast-n-Furious pics even at 206 when the t-stat is fully open the temperature is still climbing. All a lower t-stat is gonna do is throw a under temp MIL code in winter.

Don't think a 195° would throw a code in all honesty, its still within the threshold of the set temp range....but also remember this as to the fan related remarks:

Thermostats – Maintain Temperature, By Controlling Coolant Flow​

 

[stumblinhorse]

Don't think a 195° would throw a code in all honesty, its still within the threshold of the set temp range....but also remeber this as to the fan related remarks:

Thermostats – Maintain Temperature, By Controlling Coolant Flow​

Try it out. But there is 1000’s of post about high temps on wranglers. I started trying to lower the temps of my JKUR back in 2014. everything has been tried, lower t-stat mostly doesn’t have any impact since as you can see a fully open t-stat doesn’t keep the coolant temp at 203-206…. It easily goes into the 220’s and then the fan kicks on at 226. The only real solution is to turn the fan on at a lower temp…. You need to change the ECM settings to do that. Maybe you can get the Tazer guy to do a toggle?

 

[LTZ470]

Guessing the 195° will still be within the temp threshold of the ECM, so it will not throw a code...with that said, you are correct on fan settings, the 195° will probably not make any difference in stop and go traffic or crawling...out on the open highway is where we would probably observe the difference, but I tow a lot so it would probably be welcome for my needs...it wouldn't void our warranty either as Mopar is showing a 195° Thermostat in the parts fiche...I took screenshots of that page....