Overheated

[futzin']

Engine overheated with no other symptoms, other than the AC quit cooling.
2020 JTR, no mods, 25K miles.
How worried should I be?
...appointment at dealer 8/9, was nearby so I'm leaving it with them...

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[Snake Eyes]

What were you doing when it overheated? What temps were you showing on your display? Manual or auto? Etc etc etc Details

 

[futzin']

Not much to tell.
Had gotten off the interstate 5 mins prior. Normal before then. Temps quickly hit 270 or so, gauge nearly maxed, fan was running hard. Auto trans.
Was less than a mile from the dealer. I let it cool for 45 mins, restarted, promptly pegged again.
No leaks or any other symptoms.

 

[NachoRuby]

Maybe a stuck thermostat? Of course, I thought modern ones got stuck open, not closed. Sucks that they can't see you for over a week.

 

[kevman65]

Going to just have to wait for the dealership to do their thing.

Could be something simple like a bad temperature sending unit all the way up to a cracked block and you have soup in the oil pan.

But either end or somewhere in the middle, no sense in worrying about it until you know something.

 

[sass JT]

??

 

[ShadowsPapa]

Not much to tell.
Had gotten off the interstate 5 mins prior. Normal before then. Temps quickly hit 270 or so, gauge nearly maxed, fan was running hard. Auto trans.
Was less than a mile from the dealer. I let it cool for 45 mins, restarted, promptly pegged again.
No leaks or any other symptoms.

You checked the coolant level? And you have not added any coolant so there's no chance you put the wrong coolant in and it messed up?

Man, if I saw mine over 250 I'd be in shutdown mode FAST. No way I'd even think of letting it get that hot. That's where you start destroying engine parts and the oil will vaporize - no matter what else - get that oil changed. It's likely cooked.
If the gauge showed 270, you know there were localized spots over that and you boiled coolant........... and those spots got even more hot.

Sorry, and no offense - and you can call me old, old fashioned, whatever, but I'm surprised by the numbers in the forum here who drive with an engine over 250 or 260 and it doesn't bother them or they don't seem concerned, or whatever. These may be modern, but the old rules of physics still apply.

 

[futzin']

 

[Akgladiator]

Not much to tell.
Had gotten off the interstate 5 mins prior. Normal before then. Temps quickly hit 270 or so, gauge nearly maxed, fan was running hard. Auto trans.
Was less than a mile from the dealer. I let it cool for 45 mins, restarted, promptly pegged again.
No leaks or any other symptoms.

Do you ever check your coolant level?

 

[Gvsukids]

Do you ever check your coolant level?

I've had to refill mine a handful of times already this summer.

 

[ShadowsPapa]

I've had to refill mine a handful of times already this summer.

How hot is it there and do you tow a lot?

I ask because - I had my 2020 from November 14th, 2019 to July 2022
In that whole time, I added 8 ounces, ONE cup, of coolant to that 2020 truck. That's all. And it was still full when I delivered it to them. Me being me - honest to a fault, delivering as promised, and OCD, I checked all fluid levels I could easily check and made sure everything was filled before taking it to the dealer for trade.
31 months - 8 ounces of coolant. That included some towing, trip to CO and back, Pike's Peak, Fort Wayne, 100 degree heat and minus 0 degree cold.

If I have to add coolant to this 2022, I'm going to wonder what's wrong with it.
In the last 2 years I've added maybe 6 ounces of coolant to the 4.0 in my Eagle and that's not a closed system like these are.

Where is that coolant going, or what is everyone doing that they have to add on a regular basis?

 

[dcmdon]

Engine overheated with no other symptoms, other than the AC quit cooling.
2020 JTR, no mods, 25K miles.
How worried should I be?
...appointment at dealer 8/9, was nearby so I'm leaving it with them...

I wouldn't worry too much. On something that new, its 1 of 3 things.

Tstat won't open.
water pump not turning
sensor misreading.

None of which are a big deal.

 

[wanderer]

Well let me tell you a story. I was headed from the sierras around Bass lake across the 41 to the coast for work it was in my 2018JLUR in May of 2020 out of no where running about 55 mph the jeep over heats So I pull over shut it down wait a bit start it up. Same thing. I try 2 or 3 more times same. So I call triple a for stow. The lady says we can get your jeep but you can’t ride with the driver. COVID ! So I tell her there a thousand yards of fiel to my left and 2000 to my right I am literally in the middle of no where. She sorry call an Uber! Uh COVID. No Uber’s and besides out there no. Way so I drive about 16 miles going 1/4 mi at a time stopping waiting for the motor to cool down then doing it over and over until I get to the smallest jeep dealer ever. They take it fix it and he tells me just your thermostat but that being that hot for that long there could be other issues like a warped head or fried gasket. They don’t know. So 2 weeks later I traded it in on my gator green JTR. So thermostat maybe it’s an issue On the 3.2. That’s my story!

 

[mrmo]

You checked the coolant level? And you have not added any coolant so there's no chance you put the wrong coolant in and it messed up?

Man, if I saw mine over 250 I'd be in shutdown mode FAST. No way I'd even think of letting it get that hot. That's where you start destroying engine parts and the oil will vaporize - no matter what else - get that oil changed. It's likely cooked.
If the gauge showed 270, you know there were localized spots over that and you boiled coolant........... and those spots got even more hot.

Sorry, and no offense - and you can call me old, old fashioned, whatever, but I'm surprised by the numbers in the forum here who drive with an engine over 250 or 260 and it doesn't bother them or they don't seem concerned, or whatever. These may be modern, but the old rules of physics still apply.

Synthetic oil flash points are in the 350-400 deg range, so the oil did not vaporize, shear strength loss starting, yeah prob

 

[Gvsukids]

How hot is it there and do you tow a lot?

I ask because - I had my 2020 from November 14th, 2019 to July 2022
In that whole time, I added 8 ounces, ONE cup, of coolant to that 2020 truck. That's all. And it was still full when I delivered it to them. Me being me - honest to a fault, delivering as promised, and OCD, I checked all fluid levels I could easily check and made sure everything was filled before taking it to the dealer for trade.
31 months - 8 ounces of coolant. That included some towing, trip to CO and back, Pike's Peak, Fort Wayne, 100 degree heat and minus 0 degree cold.

If I have to add coolant to this 2022, I'm going to wonder what's wrong with it.
In the last 2 years I've added maybe 6 ounces of coolant to the 4.0 in my Eagle and that's not a closed system like these are.

Where is that coolant going, or what is everyone doing that they have to add on a regular basis?

I'm in Michigan, so 80's - 90's. I tow a boat every other weekend. I don't know where the liquid is going, but have an appointment for that and an oil leak from the front of the engine.

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