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Old 03-31-2019, 07:19 PM   #61
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Originally Posted by smiller1 View Post
Note that it is a known JK (actually WA580) quirk that the transmission temp PID shows the same as coolant temp when the transmission is in Park or Neutral, so you must be in a drive gear to get an accurate reading. This has gotten me a couple times, as in I looked and saw that my transmission temp was over 200F and then I realized that I was in Park. Dropped down into gear and it read 160.
Yep, fully aware of that. Thanks

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Old 03-31-2019, 08:01 PM   #62
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Almost all vehicles on the road have a grille/ covering on them. If they blocked that much air, manufactures wouldn't put them there.
All vehicles on the road have the cooling system engineered to work the way they are designed. The JK cooling system was not engineered for the disruption of the grill guards. That doesn't mean they impact the cooling system dramatically, but it does make it a different situation from a vehicle that has the system designed to be covered.
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Old 03-31-2019, 08:19 PM   #63
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@smiller1 with your a/c on the fan turns on regardless of coolant temp. That why most will recommend a/c on and temp control to full hot to help cool down on long climbs etc. That may be the explanation for seeing the fan on a low duty cycle at low 200’s.
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Old 03-31-2019, 08:46 PM   #64
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@smiller1 with your a/c on the fan turns on regardless of coolant temp. That why most will recommend a/c on and temp control to full hot to help cool down on long climbs etc. That may be the explanation for seeing the fan on a low duty cycle at low 200’s.
Not really (see below), but to eliminate any interaction I did all the initial testing with the A/C off. I only turned it on later just to see if it had any further effect on temps. A/C was not involved in the data I posted.

And FWIW turning on A/C in the Pentastar JK does not automatically turn on the fan as it might have in days past, the ECU monitors refrigerant line pressure and evaporator temp and the fan only comes on when additional airflow across the condenser is needed. So yes, the fan is often on at some speed when A/C is engaged, but not necessarily. These new-fangled vehicles are pretty damn smart.
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Old 03-31-2019, 10:34 PM   #65
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There are a slew of fan PIDs but the ones I was looking at were 'Fan on' (just a simple on/off indicator), 'OBD Fan Speed' (the commanded duty cycle), and 'Fan Speed' (the actual duty cycle, and of course this should match 'OBD Fan Speed'.)

It's worth noting that you should not use audible fan noise as your indication whether the fan is running or not because I saw duty cycles as low as 18%, where the fan is spinning quietly but actually moving a fair amount of air. You won't hear this although you can see it when looking at the fan from the engine compartment. At 30-50% you can hear some fan noise when standing in front of the vehicle, and above that the noise becomes much higher and it starts to become audible inside the vehicle.
I'll try this with the HPTuners scanner. It's wildly irritating to me that my TrailDash2 only displays a few basic things, but a $20 app will display anything FCA exposes, and make the same changes the TD2 will.

When I tested mine before modifying the start temp, I just made sure all the climate control stuff was off, and used a flashlight on the fan blades to find the 226* start temp. That worked OK, but real data from an active vehicle is better.

My setup is similar to yours: 2014 JKURX 2.5" lift, 35s.

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Old 03-31-2019, 11:24 PM   #66
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I'll try this with the HPTuners scanner. It's wildly irritating to me that my TrailDash2 only displays a few basic things, but a $20 app will display anything FCA exposes, and make the same changes the TD2 will.

When I tested mine before modifying the start temp, I just made sure all the climate control stuff was off, and used a flashlight on the fan blades to find the 226* start temp. That worked OK, but real data from an active vehicle is better.
The Jscan app will do almost everything the TD2 will do but not quite, for example it cannot yet change the fan start point or allow the lockers to operate in 4 Hi, although Jscan development seems to be very active and I believe that they are looking to add these as well. In any event it does at least provide a low-cost option for those who want to change their tire size, gear ratio, DRL settings, TPMS setpoints, and such. It also has a pretty full-featured scan tool, you can look at just about any PID from any drivetrain, chassis, or body module, very comprehensive. It's limited to Jeep products but in that realm it is more complete than anything else I've seen. You can download it and check it out for free, but you have to buy a license (per VIN) to change adaptation features.

So I guess the TD2 is not able to show you the current/existing adaptation setting, only change them? (because you had to determine the fan on point experimentally?)
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Old 03-31-2019, 11:39 PM   #67
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The TD2 doesn’t allow you to change the fan settings. It did on 3.8 models but 3.6 it is a placebo to make you feel like your are making for a cooler running engine . Currently only hptuners allows you to update the settings.
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Old 04-01-2019, 12:10 AM   #68
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Not really (see below), but to eliminate any interaction I did all the initial testing with the A/C off. I only turned it on later just to see if it had any further effect on temps. A/C was not involved in the data I posted.

And FWIW turning on A/C in the Pentastar JK does not automatically turn on the fan as it might have in days past, the ECU monitors refrigerant line pressure and evaporator temp and the fan only comes on when additional airflow across the condenser is needed. So yes, the fan is often on at some speed when A/C is engaged, but not necessarily. These new-fangled vehicles are pretty damn smart.
This is correct, but if you turn on your recirculate with your A/C, then the engine cooling fan will come on and stay on. At least that is the way that it works on my 2013 and my Grandson's 2016.

When you turn on your heater, set your controls to blow the air on the windshield. That automatically turns on the cooling fan.
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Old 04-01-2019, 03:16 AM   #69
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So I guess the TD2 is not able to show you the current/existing adaptation setting, only change them? (because you had to determine the fan on point experimentally?)
As @stumblinhorse mentioned, the TD2 won't change the fan start temp on the 3.6s. It does have a screen to display a few PIDs, but the only ones you can pick from are the same ones Jscan shows in demo mode.

Can Jscan set the TPMS threshold to less than the 22psi minimum of the TD2? That alone would make me spend the $20 on yet another scan tool.

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Old 04-01-2019, 09:54 AM   #70
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Can Jscan set the TPMS threshold to less than the 22psi minimum of the TD2? That alone would make me spend the $20 on yet another scan tool.
Yes, Jscan can set the EVIC TPMS alert setpoint down to 10 psi, and the non-EVIC down to 0.

In order to see all the possible live data PIDs you need to select 'Modules' first, else you will only see a small basic subset. I'm not sure if the full range is available in the non-licensed version or not. Data concerning the fan is available in the 'Front Control' module.

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Old 04-01-2019, 11:40 AM   #71
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As @stumblinhorse mentioned, the TD2 won't change the fan start temp on the 3.6s. It does have a screen to display a few PIDs, but the only ones you can pick from are the same ones Jscan shows in demo mode.

Can Jscan set the TPMS threshold to less than the 22psi minimum of the TD2? That alone would make me spend the $20 on yet another scan tool.

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The app is free? you need a OBDII transmitter... Or am I missing something?
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Old 04-01-2019, 12:05 PM   #72
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The app is free? you need a OBDII transmitter... Or am I missing something?
The app is free but you can't change adaptation settings without a license, which is $21. I think you may be able to read live data PIDs without a license though, not sure.

The other thing you will need is an OBDII adapter (Bluetooth dongle that plugs into the ODBII connector) but they are inexpensive. The one I used is below and it works fine. This is for Android, I think you need a different dongle for iOS. Anyway, the total for everything ends up being about $34. You can also use the Bluetooth OBDII adapter with other apps such as Torque.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
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Old 04-01-2019, 12:08 PM   #73
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I've never dinged the temp idiot bell even pulling my overweight teardrop up hills with 3.73s/33s manual trans. I've hit 230 degrees but never higher.
I've got about 126,000 miles on the mill and have R&R'd the coolant once.
I'd love to get more details about your "overweight teardrop". I'm about to pull a travel trailer up some grades so hearing your details would be great. How heavy is your teardrop? Dry -vs- loaded? What type of Jeep do you have (ie: what is your official tow capacity)?

Thanks!!!!
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Old 04-01-2019, 12:25 PM   #74
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I'd love to get more details about your "overweight teardrop". I'm about to pull a travel trailer up some grades so hearing your details would be great. How heavy is your teardrop? Dry -vs- loaded? What type of Jeep do you have (ie: what is your official tow capacity)?

Thanks!!!!
I've never weighed it but it's a 10x8 with a full galley in back. Boxed frame all around with a full (and I mean FULL) skidplate. Has 33s on 16s to match the Jeep, two 122 ah boat batteries.
Has to be pushing 3000# when we're loaded for bear.

My 2008 JK with 4.56s and 33s couldn't pull it so I got a 2011 Power Wagon ---- 5.7 Hemi and 4.56s, no problemo...
The Pentastar is the Little Engine that Almost Could with 3.73s and a manual. I wish it had 4.56s. It's rough when I see a hill coming.

Huge problem:
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No problem:
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Wish I had deeper gears:
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Old 04-01-2019, 04:56 PM   #75
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I think I discovered the reason for the discrepancy I was seeing regarding the fan on point. It seems that when in any 4WD mode the set point is around 205, but in 2WD it is around 225 (the fan comes on at 225 and runs at whatever speed necessary (in my case was about 20-30% in typical traffic, mid 80's ambient temperature) and runs until around 215 and shuts off, then the cycle repeats if you are moving slowly or stopped. When moving there seems to be enough airflow across the radiator to drop to about 200 (the thermostat temp) and the fan doesn't normally run, although I'm sure it would if you were under sufficient load to drive coolant temp above 225 while moving.

So I guess one answer is to stay in 4WD if you are in conditions that require maximum cooling off-road. It makes sense to try to maintain more cooling reserve off-road but it would be nice if there was a 'tow mode' that did this on the street as well.
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Old 04-01-2019, 05:17 PM   #76
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I think I discovered the reason for the discrepancy I was seeing regarding the fan on point. It seems that when in any 4WD mode the set point is around 205, but in 2WD it is around 225 (the fan comes on at 225 and runs at whatever speed necessary (in my case was about 20-30% in typical traffic, mid 80's ambient temperature) and runs until around 215 and shuts off, then the cycle repeats if you are moving slowly or stopped. When moving there seems to be enough airflow across the radiator to drop to about 200 (the thermostat temp) and the fan doesn't normally run, although I'm sure it would if you were under sufficient load to drive coolant temp above 225 while moving.

So I guess one answer is to stay in 4WD if you are in conditions that require maximum cooling off-road. It makes sense to try to maintain more cooling reserve off-road but it would be nice if there was a 'tow mode' that did this on the street as well.
Interesting, and your 2WD experience matches mine, +/- a degree or three. I've never had particularly warm coolant temps off road, which I attributed to generally lower RPM. (There aren't a lot of 15 minute 3500+ RPM opportunities off road, at least the way I do it.) That's part of it, but you've discovered the other part. Cool! (Pardon the pun...)

I'll have to look at my tune and see if I can find the different parameters for 2WD and 4WD in it.

Really wishing my TD2 could be made to display this...

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Old 04-01-2019, 05:26 PM   #77
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Yes, it's good when things match up. I knew what I was seeing but it didn't make sense that my vehicle would behave so differently than yours even being the same model year and everything, and now we have the answer. It probably wouldn't be beneficial to run the off-road calibration while on the street (which would result in a lot of unnecessary fan run time) under typical driving conditions, but it could be handy to be able to be able to temporarily change it under certain circumstances such as heavy towing. I guess the FCA gods didn't want that in the hands of mere humans
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Old 04-01-2019, 06:02 PM   #78
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I just got 233 on evic simply waiting in traffic (in D) - for e few seconds though the hi speed fan kicked in and the temp dropped to 212.
I stopped and let it idle and the temp was fluctuating 228 fan on (med speed) - 206 off
I never seen 233 before even off road - is there any relay or fuse for "low fan speed"?
Called the dealer got the usual answer "its normal" " bring it in". The jeep is fine no CEL light, coolant/oil level - max.
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Old 04-01-2019, 06:57 PM   #79
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Found this on a different thread:
Due to numerous variables and operating conditions, the
information the customer is seeking is unavailable.
The temperature gauge shows engine coolant temperature.
Any reading within the normal range indicates
that the engine cooling system is operating
satisfactorily.

The gauge pointer will likely indicate a higher temperature
when driving in hot weather, up mountain
grades, or when towing a trailer. It should not be
allowed to exceed the upper limits of the normal
operating range.

Low end of normal is about 105 F.
High end of normal is about 255 F.
According to available information, transmission fluid temperature can be
20 F hotter than the engine coolant temperature.

Jonathan D. Sanders
Fiat Chrysler automobiles (FCA)
Mopar Headquarters
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Old 04-01-2019, 07:08 PM   #80
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Yes, it's good when things match up. I knew what I was seeing but it didn't make sense that my vehicle would behave so differently than yours even being the same model year and everything, and now we have the answer. It probably wouldn't be beneficial to run the off-road calibration while on the street (which would result in a lot of unnecessary fan run time) under typical driving conditions, but it could be handy to be able to be able to temporarily change it under certain circumstances such as heavy towing. I guess the FCA gods didn't want that in the hands of mere humans
I'd like to update a different thread I made here discussing towing techniques. Someone said max heat but WITHOUT the A/C on. Care to comment on why AC -vs- not? I want to make sure I really understand this stuff... lol
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Old 04-01-2019, 07:36 PM   #81
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I'd like to update a different thread I made here discussing towing techniques. Someone said max heat but WITHOUT the A/C on. Care to comment on why AC -vs- not? I want to make sure I really understand this stuff... lol
If you're already running hot, the fan is already running at a high duty cycle, so turning the AC on doesn't accomplish anything. The reason you want the AC on is engage the fan earlier - at a lower coolant temp - to keep it from running hot in the first place.

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Old 04-01-2019, 09:49 PM   #82
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Found this on a different thread:
Due to numerous variables and operating conditions, the
information the customer is seeking is unavailable.
The temperature gauge shows engine coolant temperature.
Any reading within the normal range indicates
that the engine cooling system is operating
satisfactorily.

The gauge pointer will likely indicate a higher temperature
when driving in hot weather, up mountain
grades, or when towing a trailer. It should not be
allowed to exceed the upper limits of the normal
operating range.

Low end of normal is about 105 F.
High end of normal is about 255 F.
According to available information, transmission fluid temperature can be
20 F hotter than the engine coolant temperature.

Jonathan D. Sanders
Fiat Chrysler automobiles (FCA)
Mopar Headquarters

The temperatures given as 'normal' are way out of whack. If you are at 105 anytime other than during warmup then you have a bad thermostat, and if you are at 255 then you are at the point of venting coolant. Those are allowable temporary operating limits, not normal operating range.
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Old 04-01-2019, 10:12 PM   #83
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The temperatures given as 'normal' are way out of whack. If you are at 105 anytime other than during warmup then you have a bad thermostat, and if you are at 255 then you are at the point of venting coolant. Those are allowable temporary operating limits, not normal operating range.
I agree 255 doesn't look "normal"
Mine 233 at idle doesn't look "normal" to me, but something tells me i will see higher numbers with the summer heat.
I have another "hot running" motor a 2.0 liter port injected Hyundai- that thing is hot at idle~ 226 probably for emissions purposes but as soon as there is load on the motor temp drops do to thermostat electronically controlled by the ECU.
Literally going up the hill the engine is colder than at idle. Nice and simple.
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Old 04-02-2019, 09:44 AM   #84
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The Heart Rate will likely indicate a faster rate
when living in hot weather, up mountain
grades, or when towing a child. It should not be
allowed to exceed the upper limits of the normal
operating range.

Low end of normal is about 1BPM
High end of normal is about 255BPM.
According to available information, skin temperature can be hotter than the internal temperature.

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Old 04-02-2019, 04:04 PM   #85
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so I have had simial issues and sicovered a few things.



1. Grill guards will affect temperatures especially JK's with automatic transmissions and A/C due to the extra coolers mounted on the front of the rads.


2. 3.6 pentastars run hotter and suffer from heat soak. This is why every other FCA car/truck has a rad twice as big. this is why the JL has a higher speed rad fan and use the A/C system to cool the Gen 2 pentastar's. The gladiator has more open grills for the increased towing.



3. programing is bad for the electric fan especially on the 2014's.


4. OAT. It is my belief that the OAT is not as good for heat transfer compared to the old green stuff.


To combat heat I would do the following:


1. take off the grill guards/ engine cover/ rear hood seal if your doing any towing or long mountain passes/ hot summer days.


2. flush coolant system several times and go back to old green stuff (cheaper and easier to find).


3. change out tstat/ housing. Doorman has one I noticed on rockauto. havent got it yet but I have had very good luck with thier products


3. Change electric fan settings. This will require a $500 programer. Stock fan settings dont engage till 225F unless you turn on A/C. I have been looking at this one: https://www.amazon.ca/Superchips-387...ype=automotive


Changing it to engage at 210F should be optimal.


4. SWITCH YOUR OIL TO 5W30 SYNTHETIC!!! fca had to switch to 5w20 due to the caf standards back in 2012. This motor was developed to work with 5w30. early pentastar's in 2011 even had 5w30 listed on the oil cap covers.
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Old 04-02-2019, 04:43 PM   #86
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Unlees Superchips has changed something dramatically, that tuner will not alter the fan start temps on the 3.6s.

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Old 04-02-2019, 05:01 PM   #87
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so I have had simial issues and sicovered a few things.
Where in the world did you get any of those ideas? All are incorrect, except for the Gladiator cooling system upgrade but that is because it is rated to tow over 7,500 lbs. Maybe removing the grill has some effect, but if you are at that point then you really need to find out what's broken in your cooling system.
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Old 04-02-2019, 10:56 PM   #88
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Where in the world did you get any of those ideas? All are incorrect, except for the Gladiator cooling system upgrade but that is because it is rated to tow over 7,500 lbs. Maybe removing the grill has some effect, but if you are at that point then you really need to find out what's broken in your cooling system.
LOL! Having done a bunch of that stuff, though for different reasons than cooling, I can attest that most make no difference in coolant temps, at all. I'd never consider a grill cover, but did run for awhile without an engine cover. No difference. Same for opening the largely fake vents in my Rubicon X hood. I also switched to 5w-30 to quiet the racket on startup, which it did do, but it had no effect on coolant temps. I've not switched coolants or swapped thermostats. I can't imagine why anyone would do the latter if the OEM one is working, which mine is.

Turning down the fan start temp - essentially matching what you found to be the 4wd behavior - absolutely does help in most driving situations. It can't be accomplished with the tuner the previous poster mentioned, and will not help if the rig is driven hard enough in the right conditions. For that there's no substitute for cooling capacity.

IMHO, there's also something to the airflow issue, but I'm not referring to simple obstructions. Just from reading here and talking to friends with more stock bumper setups, it seems like the stock plate/dam/cover below the bumper does a better job of keeping air flowing through the radiator than aftermarket or modified setups. I've played with mine some this winter (LoD bumper) but won't know till summer if what I did helped.

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Old 04-02-2019, 11:51 PM   #89
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Originally Posted by ScaldedDog View Post
Turning down the fan start temp - essentially matching what you found to be the 4wd behavior - absolutely does help in most driving situations.
Turning down the fan start temp to 205 will definitely help keep coolant temp closer to 205, and having a fan on temp of 225 will allow excursions up to 225, no doubt there. I would question whether it helps in most driving situations though since it really doesn't matter if the temp goes up to 225 during typical street operation as long as the cooling system can easily bring it back down as desired, and in my experience it can.

I'm not an FCA engineer so I can only speculate on why they system is set up as it is, but it probably isn't for something like emissions because a closed-loop catalyst-equipped system wouldn't really benefit from running a few degrees hotter. My guess would be that they simply don't want to run that power hungry fan when it isn't necessary, and it isn't necessary for the coolant temp to always track withing a few degrees of the thermostat setting. My KL Cherokee Trailhawk behaves pretty much the same way and I bet a lot of modern vehicles do.

Now for things like towing where the load is constantly high then lowering the set point probably would help, after all if not why would they do it off-road, but towing at the limit is not most driving situations. For heavy towing a 'tow mode' that changes transmission shift patterns and cooling system parameters (as is common in pickup trucks) would probably be valuable, but let's face it, a Wrangler is not really meant for towing and FCA probably saw no reason to equip it that way. That's why the aftermarket exists I guess.

But for most driving situations the system works fine as it is and I personally don't see any value in messing with it. And again anyone who is consistently overheating in common driving conditions probably needs to get their cooling system fixed, else I and most others have special immune vehicles.
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Old 04-03-2019, 12:05 AM   #90
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I set my low temp fan to 210, and high temp to 215, which works well. It shuts off at 205, just above where the thermostat is fully open, and coolant temps stay in that range on all but the tallest passes, which was my goal. We'll see whether the modified airflow and larger radiator help enough there later this summer.

Mark

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88 4Runner on 4D's - Trailer queen for serious wheeling
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