Wrangler Rubicon JLU 3.6 engine pre-detonation

DougJaneway

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It's engine knock. I started running 89 octane and it completely quit. I'm on my second tank.
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DougJaneway

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76 fuel is what I’ve been using
Try running ether Shell v-power or any BP above 89 octane. Run a couple full tanks and let me know what you think. I've been running BP 89. Seems to have stopped the knocking. BP has some of the best detergents in their gas of anyone.
 

JMONEZ

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Try running ether Shell v-power or any BP above 89 octane. Run a couple full tanks and let me know what you think. I've been running BP 89. Seems to have stopped the knocking. BP has some of the best detergents in their gas of anyone.
Thanks, I’ll give it a go for sure whenever I get it back! Looks like it may be in the shop another week, they still haven’t diagnosed it or given me any info yet regarding this concern yet, but there is an open case. Curious to see what they have to say. Either way, it shouldn’t be pinging or knocking with 87 octane if that’s what it’s designed to use, but I’ll be happy to run 89 or 91 octane if that makes it go away!
 
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Hau82

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So after a few months after the repair the misfire came back much less but its back, now my Jeep has been at the dealership for the past 3 days, I took it in because the ESS and Start/stop service light came on (they replaced the vacuum pump to fix this problem), my rear shocks were making a bad squeak noise so they order new ones, but my main concern is the misfire (only has 6850 miles). Service advisor told me that the engine specialist tech was working on it and apparently there's some carbon build up in the throttle body and its starting to form in top of the pistons, they are going to leave the engine soaking for the weekend and clean it on Monday, I'm a little bit skeptical that this will work but I have my fingers cross
 
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Jljohnny

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I’ve been having the same problem( only 9k), seems more like a diesel rattle noise, I’ll try and upload some clips I took with GoPro. Dealer heard it too but can’t find what’s causing it, going back to dealer tomorrow for rear diff repairs, drag link, and seat track along with more diagnostics, hopefully someone can figure this noise out. 91 octane hasn’t affected mine. There are other post about engine rattle on accel that describe exact same symptoms.
What's wrong with the seat track? My driver seat feels slanted toward the center console but the dealership said it was normal....
 

walweb

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I’ve been having the same problem( only 9k), seems more like a diesel rattle noise, I’ll try and upload some clips I took with GoPro. Dealer heard it too but can’t find what’s causing it, going back to dealer tomorrow for rear diff repairs, drag link, and seat track along with more diagnostics, hopefully someone can figure this noise out. 91 octane hasn’t affected mine. There are other post about engine rattle on accel that describe exact same symptoms.
I haven't read all the entries on this tread, but mine sounds much like a diesel also. We noticed the noise, which is mostly at idle right after picking it up. it now has around 800 miles and the noise is the same.
I took it to the dealer when it first started making the noise and naturally the noise was much less than it was before, so they couldn't hear anything.
I'm going to continue driving and see if it still makes same sound after it's first oil change. Wish me luck. Headed to Moab for EJS in a week, will be interesting to see if other JL's have similar noise.
 

AZ2017JKU

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So far this is what I have done,

I plugged my obd2 scanner to my Jl port and got a green light (everything good), I pressed the red button of my scanner to “erase” codes (even dough there are no codes) this will erase all the sensors data stored in the ecu forcing it to relearn. So far everything seems back to normal, still need to drive a few more miles to complete the ecu relearn process, a soon as I get the obd2 green light I’ll post update info.
Clearing codes does not reset the adaptive memory. you either have to disconnect power or have a scanner that actually resets adaptives.
 

schumbox

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Looks like I am officially in the same boat. 2019 JLU Rubicon with 3.6L 6 speed. Noticed the pre-ignition issue after a couple days of driving it, thought it was a bad tank of fuel, ran another 2 tanks through it.
Now at the dealership...saying it is normal.. As a tuner I will say - that is not normal! Hopefully Jeep engineering can get this fixed ASAP. I HATE having to fix these things on my own!

Seems like 6 speeds were an afterthought design. #Auto-on comfort
 

Litfuse

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Looks like I am officially in the same boat. 2019 JLU Rubicon with 3.6L 6 speed. Noticed the pre-ignition issue after a couple days of driving it, thought it was a bad tank of fuel, ran another 2 tanks through it.
Now at the dealership...saying it is normal.. As a tuner I will say - that is not normal! Hopefully Jeep engineering can get this fixed ASAP. I HATE having to fix these things on my own!

Seems like 6 speeds were an afterthought design. #Auto-on comfort
If tuner like you could have fixed this issue, I would have kept my six speed JLR. I say, get to work! FCA isn’t going to fix this issue. You may find a lucrative opportunity.
 

JeepCares

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Looks like I am officially in the same boat. 2019 JLU Rubicon with 3.6L 6 speed. Noticed the pre-ignition issue after a couple days of driving it, thought it was a bad tank of fuel, ran another 2 tanks through it.
Now at the dealership...saying it is normal.. As a tuner I will say - that is not normal! Hopefully Jeep engineering can get this fixed ASAP. I HATE having to fix these things on my own!

Seems like 6 speeds were an afterthought design. #Auto-on comfort
Hi schumbox,

We’re sorry to hear about this. We certainly understand how frustrating this may be. Please feel free to let us know if you decide to continue working with your dealer to address this and we will gladly assist you during that process.

Lydia
Jeep Social Care Specialist
 

JMONEZ

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Looks like I am officially in the same boat. 2019 JLU Rubicon with 3.6L 6 speed. Noticed the pre-ignition issue after a couple days of driving it, thought it was a bad tank of fuel, ran another 2 tanks through it.
Now at the dealership...saying it is normal.. As a tuner I will say - that is not normal! Hopefully Jeep engineering can get this fixed ASAP. I HATE having to fix these things on my own!

Seems like 6 speeds were an afterthought design. #Auto-on comfort
Warmer ambient temps make it more pronounced! It’s gotta be a timing issue, I would hope at some point soon FCA will come out with an easy software update to resolve it, meanwhile though potential internal failures could be brewing!
 
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