3.6L stock issue (everyone should have this)

[BullittEV]

There are a few circumstances that could be the issue. I understand the basics of vehicles but I am not a mechanic or have that in depth knowledge.

On the 3.8L and the 3.6L I've noticed that there seems to be a throttling issue at around the 50+mph speeds. It gets up to speed fine but at highway speeds when I am looking for an even powerband- it is stagnant as I push the pedal down, which seems like it does nothing to alert the ECU to increase RPM's. When the pedal gets to about 75% it jumps RPM's, hard- example from 2500-4000, instantly.

I figured this issue was isolated to my older 2008 3.8L JKU but I test drove a 2021 3.6 and it does the same exact thing.

-It doesnt do this on my buddies 2020 2-dr Rubicon with a manual transmission.

So it's narrowed down to a few things:

-The 3.45 gear ratio
-The extra weight of the 4dr
-ECU Throttle control
-The auto transmission lag (although it was a 4spd from 2008 vs the 8speed on the 2021)

Or maybe a combination of these.. Would love an experienced view on this issue that seemingly comes with all 4dr autos.

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[Stuckinthesand]

I’m pretty sure it has to do with the drive by wire throttle. I also have the 3.6 8 speed and noticed the same thing after 50mph. Did some research and found this is very common(99%) complaint with jeeps in general. I just ordered the hikeit throttle controller as I have read good things about it and it’s cheaper than some of the other throttle controllers out there. Going to see how this works out. All the videos on YouTube that use the hikeit all are very happy with it.

 

[BullittEV]

I’m pretty sure it has to do with the drive by wire throttle. I also have the 3.6 8 speed and noticed the same thing after 50mph. Did some research and found this is very common(99%) complaint with jeeps in general. I just ordered the hikeit throttle controller as I have read good things about it and it’s cheaper than some of the other throttle controllers out there. Going to see how this works out. All the videos on YouTube that use the hikeit all are very happy with it.

That is crazy Jeep never addressed this.

Thanks. I saw the hike it controller also.. You going for the x5 or x9?

I read this on another forum:

Besides all that, I am definitely not interested in a pedal commander or similar device that plugs between the pedal and harness to the pedal. Lots of hype, but what they actually do is exaggerate the signal to make things feel more responsive. In other words, press the pedal 50% down, it changes the signal to 80% down, or 70 or 60 (or whatever) depending on what "level" you set it to. Doesn't take out the soft open or close effect on the throttle.

I wonder if throttle controllers dont actually give linear power but just simulate the pedal being down further than it really is which still causes the RPM spike.

 

[wibornz]

I run a Hike x9. I love it. You can custom tune how you want your throttle response to work. I use the cruise mode for normal driving and towing my camper set at 6. I use the ECO 4x4 mode for off roading set at 7 and HI performance mode for playing around. Super easy to install

 

[Stuckinthesand]

That is crazy Jeep never addressed this.

Thanks. I saw the hike it controller also.. You going for the x5 or x9?

I read this on another forum:



I wonder if throttle controllers dont actually give linear power but just simulate the pedal being down further than it really is which still causes the RPM spike.

I am going with the X9. Use code fb10 and you get 10 or 20% off can’t remember which one. I got the controller and a face plate for $184. It shouldn’t cause the spike as the controller is actually taking the delay out of the ECU by sending an instant signal. I’ll let you know how it works once I get mine.

 

[Stuckinthesand]

The X9 has a clever PCB module which updates the points of reference for a vehicles throttle mapping. Throttle Lag is added by manufacturers for a number of reasons including fuel economy. The HIKE IT X9 maintains the standard parameters of your vehicle; however, introduces a sharper throttle curve (or smoother when in 4x4 Eco mode) and reduces the "dead zone" in your cars accelerator pedal

 

[The Last Cowboy]

The lag at highway speed is for fuel economy reasons and is part of the throttle program algorithm. Pedal Commander and similar products allow the throttle movement to more closely resemble the input you give to the accelerator. These products give better, more linear throttle response.

 

[mwilk012]

Jeep hasn’t addressed it because it isn’t a problem. This engine likes high RPM.

 

[BullittEV]

I am going with the X9. Use code fb10 and you get 10 or 20% off can’t remember which one. I got the controller and a face plate for $184. It shouldn’t cause the spike as the controller is actually taking the delay out of the ECU by sending an instant signal. I’ll let you know how it works once I get mine.

The lag at highway speed is for fuel economy reasons and is part of the throttle program algorithm. Pedal Commander and similar products allow the throttle movement to more closely resemble the input you give to the accelerator. These products give better, more linear throttle response.

Sounds good, then this product is exactly what I am interested in.

Jeep hasn’t addressed it because it isn’t a problem. This engine likes high RPM.

I have nothing against the engine. I just dont understand why Jeep would want the engine to go from low load to high load so quickly.. The idea with engines, or anything mechanical, is that the best way to get up to speed safely would be gradually. Do you really think spiking engine load is better than linear power?

 

[DanW]

There are a few circumstances that could be the issue. I understand the basics of vehicles but I am not a mechanic or have that in depth knowledge.

On the 3.8L and the 3.6L I've noticed that there seems to be a throttling issue at around the 50+mph speeds. It gets up to speed fine but at highway speeds when I am looking for an even powerband- it is stagnant as I push the pedal down, which seems like it does nothing to alert the ECU to increase RPM's. When the pedal gets to about 75% it jumps RPM's, hard- example from 2500-4000, instantly.

I figured this issue was isolated to my older 2008 3.8L JKU but I test drove a 2021 3.6 and it does the same exact thing.

-It doesnt do this on my buddies 2020 2-dr Rubicon with a manual transmission.

So it's narrowed down to a few things:

-The 3.45 gear ratio
-The extra weight of the 4dr
-ECU Throttle control
-The auto transmission lag (although it was a 4spd from 2008 vs the 8speed on the 2021)

Or maybe a combination of these.. Would love an experienced view on this issue that seemingly comes with all 4dr autos.

I've never noticed it on either my 3.8 or 3.6. I still have the 3.8, too. I've also got the manual transmission in both, so maybe it only does it with the auto?

 

[JDub11]

Sounds to me like your explaining the transmission down shifting thus the rpms kick up. These engines power is at high rpm. If you cruising along at 50 and then hit the peddle for more speed the engine dosent have enough power to accelerate there for it has to down shift to make up for lack of power.

 

[mwilk012]

I've never noticed it on either my 3.8 or 3.6. I still have the 3.8, too. I've also got the manual transmission in both, so maybe it only does it with the auto?

well yea, it’s only with the auto because it’s downshifting. If you throw it in 4th going up a high, your RPM’s are going to jump.

 

[mwilk012]

Sounds good, then this product is exactly what I am interested in.



I have nothing against the engine. I just dont understand why Jeep would want the engine to go from low load to high load so quickly.. The idea with engines, or anything mechanical, is that the best way to get up to speed safely would be gradually. Do you really think spiking engine load is better than linear power?

It’s just downshifting, my dude. This engine is never going to get up and go without shifting down to raise rpm >3000.

 

[MaineBumpkin]

It's not just Jeep or even FCA, my 2015 RAM had horrible throttle response so I installed a device similar to the x9. I've also driven a wide variety of rental vehicles over the past several years (both US and Europe) and found they always want to seek higher gears and lower RPM's so downshifts require more throttle input. My Renegade drives me crazy on the highway, it always drops 5MPH on hills so now I just kick it over to manual and do the shifting myself. Some call this the Cafe effect but that's topic for the Chat Lounge

 

[Rico1111]

It’s just downshifting, my dude. This engine is never going to get up and go without shifting down to raise rpm >3000.

Absolutely! My 2 door is actually quite quick and a lot of fun .....once I understood the fact that low gears at high rpm make it get going!! I now always enter the highway in 3rd and actually get it to 70 before shifting to 4th and there seems to be a point at which it gets a boost almost like a turbo.....happens every time! Once I realized this it has been like driving a whole different vehicle all together. The 3.6 really does love to be mashed!

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