Is my coolant temperature too high?

[RubiXplr]

Hello - I noticed my 2019 JLUR 2.0T (with BSG/eTorque) engine oil and coolant temperatures rise to ~235F and shortly after drop back to ~190F. This kept happening for the rest of the drive (about 1 hour). I rarely see temps above 210F. The two temperatures seem to go up/down together which has me rule out the sensors. I only noted this yesterday. Temps increased when stopped at a light and drop back down as I picked up speed. It seems as if the air flow across the radiator isn’t adequate, so it makes me think it’s the fan, which I have yet to check.

Coolant level is fine and I see no signs of leaks.

Thoughts? What’s an easy way to check functionality of the fan? Anything else come to mind as a potential problem to rule out?

76k miles on the clock

Sponsored

 

[RubiXplr]

Update: Temps have stayed at normal levels without any changes since the day I initially posted (1 week ago). Anyone experience this?

I was about to proactively replace my coolant reservoir with an aftermarket Aluminum one (seen lots of complaints about the two piece black plastic one), but I’m hesitant to change anything before I figure out what caused the original elevated coolant temp.

 

[Lithics]

Following.
I'm experiencing similar. Never had issues, never seen much over 220. Now I'm 700 miles from home in Moab seeing spikes to 235 and 239 on incredibly mild uphill climbs on dirt roads going 30mph. Haven't even hit any real trails yet, doubt I will at this point. Coolant levels are spot on. 2021 JLUR 2.0T non-eTorque, purchased new.

 

[Capricorn]

Yeah, normal if you are in a stop and go traffic, and/or going uphill. As soon as the fan kicks in, or have high speed driving on the freeway, coolant temps should drop down. Coolant temps also go higher if you are not using the A/C and ambient temps are over 75F. When A/C is turned on the fan also kicks in. The higher the ambient temp, and if you are running the A/C, the cooling system is more active.
Even at 235F, you will notice that the gauge doesn't move up more than the 1/2 level so it is within operating temp.

 

[RubiXplr]

Yeah, normal if you are in a stop and go traffic, and/or going uphill. As soon as the fan kicks in, or have high speed driving on the freeway, coolant temps should drop down. Coolant temps also go higher if you are not using the A/C and ambient temps are over 75F. When A/C is turned on the fan also kicks in. The higher the ambient temp, and if you are running the A/C, the cooling system is more active.
Even at 235F, you will notice that the gauge doesn't move up more than the 1/2 level so it is within operating temp.

I’ve seen other threads that indicate the that the coolant gauge is almost always just under half and jumps to HOT/RED at ~250F. That gauge is definitely not linear. I’m expecting the thing to switch to HOT/RED with no notice. Some in other threads speculate that Jeep designed the gauge this way to minimize the number of complaints.

As an additional update to my original post, my fan is working. I hear it running at times. I just can’t figure out the logic as to when it kicks in. It also does cool the system down fast when it kicks in. I’m just surprised that I’m experiencing a 40 F swing.

So far, I’m considering this normal operation. Next steps for me are:
1) I plan to swap out my coolant tank, which should not affect anything mentioned in this thread.
2) I also plan to flush and change the coolant.
3) I’m considering changing the thermostat.
Will report back if anything changes.

 

[roaniecowpony]

From my 3.6 experiences and posts from others with 2.0T engines, your temperatures sound similar to what others are seeing. I'm not saying it's good.

My 3.6 engine would do about the same. After that engine went south and I replaced it, I installed a larger radiator, larger fan, and less restrictive grill. That ended with no significant change. Once i installed a RPM Extreme fan controller, temperatures stayed between 194f and 215

 

[EbyCreek]

I’ve seen other threads that indicate the that the coolant gauge is almost always just under half and jumps to HOT/RED at ~250F. That gauge is definitely not linear. I’m expecting the thing to switch to HOT/RED with no notice. Some in other threads speculate that Jeep designed the gauge this way to minimize the number of complaints.

As an additional update to my original post, my fan is working. I hear it running at times. I just can’t figure out the logic as to when it kicks in. It also does cool the system down fast when it kicks in. I’m just surprised that I’m experiencing a 40 F swing.

So far, I’m considering this normal operation. Next steps for me are:
1) I plan to swap out my coolant tank, which should not affect anything mentioned in this thread.
2) I also plan to flush and change the coolant.
3) I’m considering changing the thermostat.
Will report back if anything changes.

I think the RPM Extreme Fan Controller is the best and easiest fix. I’ve never been above 207 since I installed mine. The factory fan settings are crazy high.

 

[NWJeepr]

It's normal for the 2.0 (and many other engines) to operate within a temperature range. Without airflow through the radiator, like in low speed stop/go traffic, engines will build some heat and rely on the fan to push temperatures back down after a while.

The turbo (exhaust gas temperatures) will increase oil and coolant temperatures when under high load/boost. It's very noticeable at low RPM when you're applying throttle because the turbo is under load. You'll also notice higher temperatures - oil/coolant - on the highway in rolling terrain when you're applying lots of throttle in 8th to maintain speed. It's not wrong to have a little mechanical sympathy and manually shift to 7 or a gear where you can consistently keep the RPM slightly higher. This should reduce EGT and potentially save a few transmission shifts as well.

The turbo is on its own liquid cooling circuit and cools itself in the engine bay. It shares oil with the engine.

The coolant for the 2.0 is good for 10 years and more than 100k miles. If there's any doubt if the coolant is still good, you can get test strips which should give you an idea of the coolant concentration as well as overall pH.

 

[RubiXplr]

I think the RPM Extreme Fan Controller is the best and easiest fix. I’ve never been above 207 since I installed mine. The factory fan settings are crazy high.

Thank you for sharing these factory fam settings. It explains what I’m experiencing and confirms that the operation of my JLUR is “normal”, as designed.

 

[RubiXplr]

It's normal for the 2.0 (and many other engines) to operate within a temperature range. Without airflow through the radiator, like in low speed stop/go traffic, engines will build some heat and rely on the fan to push temperatures back down after a while.

The turbo (exhaust gas temperatures) will increase oil and coolant temperatures when under high load/boost. It's very noticeable at low RPM when you're applying throttle because the turbo is under load. You'll also notice higher temperatures - oil/coolant - on the highway in rolling terrain when you're applying lots of throttle in 8th to maintain speed. It's not wrong to have a little mechanical sympathy and manually shift to 7 or a gear where you can consistently keep the RPM slightly higher. This should reduce EGT and potentially save a few transmission shifts as well.

The turbo is on its own liquid cooling circuit and cools itself in the engine bay. It shares oil with the engine.

The coolant for the 2.0 is good for 10 years and more than 100k miles. If there's any doubt if the coolant is still good, you can get test strips which should give you an idea of the coolant concentration as well as overall pH.

Helpful. Thank you!

 

[DirtWrangler]

I’ve seen other threads that indicate the that the coolant gauge is almost always just under half and jumps to HOT/RED at ~250F. That gauge is definitely not linear. I’m expecting the thing to switch to HOT/RED with no notice. Some in other threads speculate that Jeep designed the gauge this way to minimize the number of complaints..

This answers my question. We just picked up a 2021 JL Sport S. The coolant temp gauge quickly goes up to just below half and doesn’t budge while the digital temp readout varies from 190 to 225. I don’t think I’ve ever seen coolant temps vary so much so quickly. I assume it’s because of the small heat mass of the 2.0L engine. Quite unlike the coolant temps in our 3500 Ram dually with the 6.7L diesel.

The analog gauge is next to worthless. They should just put a green light for normal and a red light for hot if it’s an “on/off” readout. Why try to trick us into thinking we have a nice, functional analog gauge?

 

[Heimkehr]

We just picked up a 2021 JL Sport S. The coolant temp gauge quickly goes up to just below half and doesn’t budge while the digital temp readout varies from 190 to 225. I don’t think I’ve ever seen coolant temps vary so much so quickly. I assume it’s because of the small heat mass of the 2.0L engine.

The analog gauge is next to worthless. They should just put a green light for normal and a red light for hot if it’s an “on/off” readout. Why try to trick us into thinking we have a nice, functional analog gauge?

The 2.0T's exhaust manifold has a built-in liquid cooling circuit. This is why, for example, warm air will begin to exit the dash vents rather quickly after a cold start on a cold day. It also helps to explain why the temperature trends on the digital Coolant Temperature gauge might appear odd when compared to a vehicle that has a simpler cooling system.

I do agree that the binary OK/Not OK functioning of the analog temperature gauge might've been an intentional dumbing-down to avoid anticipated complaints by uninformed owners.

 

[Tr4ckD4ys]

I still think the factory fan settings are ridiculous. My engine spends relatively speaking a lot more time above 220F coolant than any other engine I’ve owned. Of course only long term will show what the impact is but boy, a little less temp surely can’t hurt the reliability.

Sponsored