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Cooling problems with 3.6

Petey

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Been having cooling issues with the 3.6 - can’t maintain a climb at any sort of speed without overheating - it’s always coolant never anything else - even on flat highways it risks overheating at speed on hot days - coolant has recently been replaced and the issue is persisting

Here In colorado we’ve got quite a heatwave going and it’s been overheating on the highway constantly, even canyon roads at 50 mph - further, on the CA-NV state line it overheats nearly every time I drive through there over the summer

Not really sure what options I have - I removed my lights mounted in front of the grille and that helped, I remove my winch cover and that occasionally helps… but no matter what I’m dealing with overheating

Any advice?

I have a barricade bumper where the winch blocks part of the lower grille

Im also trying to find a grille & hood that allows more airflow - please send any recommendations
Yep you're not the only one.. but theres a lot of things that can do this .. like when a fan doesn't come on in a timely fashion. I'm going to add an auxiliary radiator myself . As far as opening up more area in front of the vehicle is a waste of time in my opinion ...especially if jeeps come with a system with too low of a capacity to cool.
 

Petey

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coolant gets so hot the car will go into limp mode and the gauge is maxed out
i'll addd that mine never went that far so u might be having head gasket /sealing issues
 
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HungryHound

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Don't worry about airflow thru the grille, it's most likely air in the system or maybe the thermostat as long as you hear the aux fan running. Take it back to the dealer who did the coolant change and let them go thru the steps of properly troubleshooting the system. Ambient temperature and engine load have little influence on overheating in these newer systems as long as everything is set-up and running right.

As others have mentioned, rock-crawling in triple-digit temperatures in Moab and towing in the upper 90s have never affected coolant temperature in my Jeep. The system is solid as long as the tech working on it didn't go all wakey-bakey before work.
 
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Joaquim

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i'll addd that mine never went that far so u might be having head gasket /sealing issues
It only went to far as that in 125 degree weather… most of the time it just heats up a ton and I’ve got to turn the AC off and glide behind a truck… but I’m literally getting passed by Uhauls & semi trucks on the highway in 100 degree weather
 

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It only went to far as that in 125 degree weather… most of the time it just heats up a ton and I’ve got to turn the AC off and glide behind a truck… but I’m literally getting passed by Uhauls & semi trucks on the highway in 100 degree weather
How long has this been going on for? I wouldn’t be driving it anymore, going to warp the heads getting that hot over and over
 

Petey

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It only went to far as that in 125 degree weather… most of the time it just heats up a ton and I’ve got to turn the AC off and glide behind a truck… but I’m literally getting passed by Uhauls & semi trucks on the highway in 100 degree weather
125 degree weather ...say hi to satan for me ... joke aside, here in FL we don't get that hot but still plenty warm .. i have to run the ac especially in stop and go traffic because it keeps the fan on for longer duration so the temps in the radiator dont spike so much. i think u might even be able make urself a sprayer system for the the radiator ..its pretty effective at dropping the temps and not too complicated but that would be a band aid in the long term in my opinion. U would still need an additional water canister that would need to be filled often. If u dont have an issue with the actual engine I would look into tying ann additional radiator/cooler into the cooling system this will definitely help u even if u have a blown gasket
 

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There is definitely something broken, or the dealer messed something up. it’s not your bumper or winch!
As others have said I’ve had our couple Jeep models through the years working hard in triple digits at slow speeds and they never faltered. I think the pentastar is very effective at cooling.
Not an issue AT ALL like the ecodiesel.
 

mwilk012

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Have you been adding coolant?

Wait a minute, is this the same Jeep with the timing faults?
 

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Just curious if the Jeeps going to the desert countries Saudi Arabia etc have larger radiators??
 

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mwilk012

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Just curious if the Jeeps going to the desert countries Saudi Arabia etc have larger radiators??
60/40 water/coolant helps in extreme hot temperatures. Or more. As long as you can keep corrosion down, water cools much better than glycol.
 
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Joaquim

Joaquim

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Have you been adding coolant?

Wait a minute, is this the same Jeep with the timing faults?
No I haven’t been adding anything - and Yes the cooling issue has been persistent for a year, the timing faults 4 weeks, both unresolved - dealer is awful here and is still waiting on new ECU (it’s one of the first production 2018 JLUs so it’s around 4 years old and I use it consistently for off-roading in -20 to +125 degree weather) - the past few weeks it is has been nothing but trouble but somehow has not died on me, debating whether to sell/replace or completely overhaul in a few months

overheating coolant happens in 3 main situations: 1. Driving in the Mojave uphill for a while in extremely high temperatures attempting to maintain 50mph+ 2. Driving up I70 (7-10k ft altitude) and trying to climb at 50+ mph 3. Driving on a flat highway at high temps and high incoming winds
 
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Joaquim

Joaquim

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60/40 water/coolant helps in extreme hot temperatures. Or more. As long as you can keep corrosion down, water cools much better than glycol.
Distilled water to prevent corrosion correct? With 40% pure coolant?
 
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Joaquim

Joaquim

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I’ve attached a picture of the coolant reservoir & the front of the grille (yes I know the winch rollers are broken)

Jeep Wrangler JL Cooling problems with 3.6 2EC4F2DC-4F68-4ACB-8C63-243723D925C0


Jeep Wrangler JL Cooling problems with 3.6 0ACACB33-133C-4056-ADA6-12909B4A90CC
 
 







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