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2017 JKU is running hot

Flipflop

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My 2017 jku Sahara unlimited is still running hot after i changed the radiator cap, thermostat, properly burped the system. My dial is in the middle at 165*degrees .. is that about right?
Also the fans are working, high and low. When I’m running around neighborhood it’s like 217-228 .. the highway is 226-244. And at 244 it’s a little past the 3/4 mark..it’s actually running hotter now that I changed the thermostat by about 5-6 degrees.. no dash lights are on.. it has a 3.5 lift with 33 12/50s on 20s. Uhmm, should I change the coolant temp sensor? I really need this fixed. I have a trip in 20days plus it’s my daily driver. Asking for a friend
 

Threepointsix

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No codes, no concern would be my MO. If you feel safer changing the coolant temp sensor, go a head. Its cheap enough and super easy to do.

My suggestion is to NOT release the radiator cap when doing the job. This way you won't lose much coolant when changing the sensor. And def go MOPAR replacement 100%. If you need to replace what you lost, (shouldn't be much) add it to the reservoir. Worked out perfect for me.

Best of wishes✅
 

BLACKJKU

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The torque converter's they have a lockup kinda like another gear.

Do you have any lights on in your dash cluster, one that says hot oil?
 
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Dirty Dog

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It’s a automatic yes.

What do you mean autos lock up?
Automatic transmissions do not have a mechanical connection to the engine. They have a hydraulic connection via the torque converter. This allows the engine and transmission to spin at different speeds. Otherwise, when you stopped, the engine would die, just the same as a manual does if you don't engage the clutch.

At some point, the torque converter will "lock up", which means the engine and transmission are spinning together. When this happens depends on a lot of things. But if the torque converter is locking up incorrectly, it can increase the engine load and drive up the temperature.

Lock up is also called "stall speed" or "flash speed", especially in racing circles. A torque converter with an intentionally high RPM stall/flash/lock up is called "loose". It is common practice to run a loose converter on performance cars with automatics, because when you hammer the throttle, the loose converter will allow the engine to jump up to the stall speed of the converter. This puts the engine in it's powerband immediately. Driving a car like this can feel a bit weird, because the engine will immediately jump to, say 3500 RPM, and then hold there until the car accelerates enough that the transmission catches up to the engine. At that point, RPM will start to rise.

This is the whole point behind the development of the CVT (Continuously Variable Transmission). It eliminates any gears. The engine flashes to whatever RPM is the absolute peak of the power band, and stays there the entire time you've got your foot planted.
 
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TROY66/68

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Automatic transmissions do not have a mechanical connection to the engine. They have a hydraulic connection via the torque converter. This allows the engine and transmission to spin at different speeds. Otherwise, when you stopped, the engine would die, just the same as a manual does if you don't engage the clutch.

At some point, the torque converter will "lock up", which means the engine and transmission are spinning together. When this happens depends on a lot of things. But if the torque converter is locking up incorrectly, it can increase the engine load and drive up the temperature.

Lock up is also called "stall speed" or "flash speed", especially in racing circles. A torque converter with an intentionally high RPM stall/flash/lock up is called "loose". It is common practice to run a loose converter on performance cars with automatics, because when you hammer the throttle, the loose converter will allow the engine to jump up to the stall speed of the converter. This puts the engine in it's powerband immediately. Driving a car like this can feel a bit weird, because the engine will immediately jump to, say 3500 RPM, and then hold there until the car accelerates enough that the transmission catches up to the engine. At that point, RPM will start to rise.

This is the whole point behind the development of the CVT (Continuously Variable Transmission). It eliminates any gears. The engine flashes to whatever RPM is the absolute peak of the power band, and stays there the entire time you've got your foot planted.
And you learn all this in Nursing School. WOW. Just fooling around. I know what stall speed is, I was a small aircraft pilot. And I am not jumping out of a plane that does have engine failure. LOL.
 
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Dirty Dog

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And you learn all this in Nursing School.
Nope. And they didn't teach it when I went back for my MS in Human Physiology either! What's wrong with the education system????

The thing is, nobody goes into nursing to get rich. But I have expensive hobbies. More so when you have to pay someone else.
WOW. Just fooling around.
I know. :)
I know what stall speed is, I was a small aircraft pilot.
That's another expensive hobby I'd love to participate in. One of my TKD students is now flying an E-3 Hawkeye off a carrier.
But my reply was mostly for @Flipflop, who asked about lockup.
And I am not jumping out of a plane that does have engine failure. LOL.
I don't do it very often, honestly. I do it because I am absolutely terrified of heights. I have always believed that we must control our fears, rather than let them control us. So I jump out of airplanes.
 
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Anybodyhome

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That's another expensive hobby I'd love to participate in. One of my TKD students is now flying an E-3 Hawkeye off a carrier.
But my reply was mostly for @Flipflop, who asked about lockup.
The E-2 Hawkeye (Nothrop-Grumman) is the carrier-based turbo-prop aircraft you speak of. The E-3 Sentry (Boeing) is the Air Force jet-powered version.
 
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Flipflop

Flipflop

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Did you use the proper coolant? If you didn't match coolant or mixed 2 different coolants, this will cause problems as well.
I took it to a shop, they find no leaks, and yes proper coolant.. told me it’s probably a head gasket leak.. it only have 50k miles on it.. but they didn’t do a gas test on the coolant yo
Actually confirm that.. idk what imma do.. I literally just bought it as is 30 days ago
 

mrjp

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I took it to a shop, they find no leaks, and yes proper coolant.. told me it’s probably a head gasket leak.. it only have 50k miles on it.. but they didn’t do a gas test on the coolant yo
Actually confirm that.. idk what imma do.. I literally just bought it as is 30 days ago
My guess would be they knew it had a problem when they sold it.
 
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Flipflop

Flipflop

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My guess would be they knew it had a problem when they sold it.
I took to back to dealership, allowed them to changed coolant temp sensor and radiator, still running hot

E131DE57-490A-4FEF-916A-122FA8632D62.jpeg
 

Anybodyhome

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It's still under warranty with 50k miles? If so, I'd tell them to pressure test it for a head gasket. But, I think you'd be throwing several codes which would be indicative of a head gasket leak.
 
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Flipflop

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It's still under warranty with 50k miles? If so, I'd tell them to pressure test it for a head gasket. But, I think you'd be throwing several codes which would be indicative of a head gasket leak.
I think it just ran out of warranty… I believe it was first bought in late 2016 . It’s a 2017.
Factory warranty is 5 year or 60k whichever is first on power train?
 
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