Survey- For those with misfire issues

[ShadowsPapa]

Hey! Purchased my Mojave JT on Veterans Day, 2021. CEL came on within a month or so of city/highway/off-pavement and light (2Klb) trailer tow driving. The engine has developed a rough sound at all times but otherwise drives fine.
Mileage when it first occurred: 700 miles
How many times has it occurred: 20 or more
What exact codes did it throw: P300 and others
Is the issue on going? Yes
If so, what has been done to try to solve the issue? Dealer read and reset the codes. CEL came back after a week or so. Dealer troubleshot and asked to keep it overnight. Needed more trouble shooting time so set up a new appointment. Changed 2 oxygen sensors, reset codes. CEL came back in a week or so, dealer verified P300 as main issue and set up a new appointment. Dealer found one of the catalytic converters running 30 degrees cooler. Dealer ordered and changed the cooler running catalytic converter and reset codes. CEL came back on after a week or two. Dealer verified P300 and set up a new appointment for 3rd week in June 2022.
Was the issue ever fully resolved? Y/N
Build date: 092220 DOM: 9-21

A converter that has not "lit off" may be a symptom of an engine issue, too - mixture troubles. They need to look at those things, catch a log, freeze frame, and look at the long term and short term numbers.
A cool converter unless plugged shouldn't cause a misfire, but what's causing the misfire could be causing converter temperature issues...... at least that's my opinion and logic.

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[bkmorgan64]

Purchased a 2022 Gladiator Rubicon 8 weeks ago. 4weeks ago the CEL light cam on at 311 miles. Took it to the dealer immediately. Its still there 4 weeks later. P0301 and the P0300 code. Dealer hasn't a clue on what's causing the issue. Corporate engineers are now involved trying to figure it out. Not too pleased with the whole situation right now. Making payment on a 60K vehicle and cant even drive it. I am going to guess the build date was early 2022 or late 2021. Being at the dealer, i cant get to it

 

[ShadowsPapa]

Purchased a 2022 Gladiator Rubicon 8 weeks ago. 4weeks ago the CEL light cam on at 311 miles. Took it to the dealer immediately. Its still there 4 weeks later. P0301 and the P0300 code. Dealer hasn't a clue on what's causing the issue. Corporate engineers are now involved trying to figure it out. Not too pleased with the whole situation right now. Making payment on a 60K vehicle and cant even drive it. I am going to guess the build date was early 2022 or late 2021. Being at the dealer, i cant get to it

I would think with the extremely low miles on it, and it's been out of service for 4 weeks, they'd do a buyback and be done with it.

 

[Eeeckman]

A converter that has not "lit off" may be a symptom of an engine issue, too - mixture troubles. They need to look at those things, catch a log, freeze frame, and look at the long term and short term numbers.
A cool converter unless plugged shouldn't cause a misfire, but what's causing the misfire could be causing converter temperature issues...... at least that's my opinion and logic.

My thoughts too, I'm sure the techs are following a troubleshooting tree. I'm very happy with the service dept and their efforts - its one of those things that takes time to nail down.

 

[ShadowsPapa]

My thoughts too, I'm sure the techs are following a troubleshooting tree. I'm very happy with the service dept and their efforts - its one of those things that takes time to nail down.

Yes, it definitely can, and when working within the constraints of the warranty, if they don't follow Jeep protocol, they don't get paid back.

 

[Snook]

Build date: March 17, 2022
Mileage when it first occurred: 2870
How many times has it occurred: 1
What exact codes did it throw: PO300 PO303
Is the issue on going? Y
If so, what has been done to try to solve the issue?: Dealer cleared the code and suggested watching to see if it happens again.
Was the issue ever fully resolved?: N


While on vacation in FL we got a Flashing CEL after backing out of parking space. Vehicle was still running fine. Flashing CEL went off aprox 10 minutes after on the drive home.
After getting back, we located the nearest dealer, Schumacher Chrysler Jeep in Delray Beach FL.
As we pulled out to start our drive to the dealer the CEL came on but did not flash. Vehicle ran fine all the way to the dealer, approx 15 miles.
Service manager Robert Corman scanned the Jeep and detected a PO300 code. He cleared the code and said to watch it to see if it happens again, seeing as they were backed up in their service department. We left and had no more issues. We drove back to Atlanta on 6/24 towing our boat 600+ miles with no issues. Gas mileage was 13.8.

NOTE: the ASS never once activated the whole time. The weather was very hot and the AC was in high most of the time.

 

[Hootbro]

NOTE: the ASS never once activated the whole time. The weather was very hot and the AC was in high most of the time.

ESS will not work by design if the HVAC temp is set to LO and in recirculate. There is a list of parameters in the OM that gives all the conditions the ESS will not activate or be available.

 

[ShadowsPapa]

Actually it's a partial list. There's a more technical list that includes catalytic converter temperatures, steering wheel input pressure, among other things.

From "the book" ->
Possible Reasons The Engine Does Not Autostop
Prior to engine shut down, the system will check many safety
and comfort conditions to see if they are fulfilled. Detailed
information about the operation of the Stop/Start system
may be viewed in the instrument cluster display Stop/Start
Screen. In the following situations, the engine will not stop:
• Driver’s seat belt is not buckled
• Driver’s door is not closed
• Battery temperature is too warm or cold
• Battery charge is low
• The vehicle is on a steep grade
• Cabin heating or cooling is in process and an acceptable
cabin temperature has not been achieved
• HVAC is set to full defrost mode at a high blower speed
• HVAC set to MAX A/C
• Engine has not reached normal operating temperature
• Engine temperature too high
• The transmission is not in a forward gear
• Hood is open
• 4WD system is put into 4L or Neutral
• Brake pedal is not pressed with sufficient pressure <- I use this one to control when I do or do not want it to shut down depending on traffic and if the light is a stale read, I don't apply enough brake pedal pressure to trigger ESS
Other Factors Which Can Inhibit Autostop Include:
• Accelerator pedal input
• Vehicle speed threshold not achieved from previous
auto-stop
• Steering angle beyond threshold
• ACC is on and speed is set
• Vehicle is at high altitude
• System fault present

 

[Pglover91]

Welp. Still an issue. ‘22 sport s with 1477 miles. Blinking CEL with what feels to be misfires. Towed to the dealer and should have more info tomorrow. Lovely.

Update: The jeep was initially returned a week later and the dealer said they were having trouble recreating the issue but could see misfire codes had been thrown.
Fast forward two months of intermittent CELs that would pop up and go away. I returned the jeep to the dealer a few days ago with a consistent CEL. Can see the misfire codes and the engine is now being taken apart. No telling what the issue is but very frustrating having had the car for 3 months and now in the shop for a third time with zero success.
Third times the charm? Who knows…should’ve stuck with a wrangler.

 

[Snook]

Update: The jeep was initially returned a week later and the dealer said they were having trouble recreating the issue but could see misfire codes had been thrown.
Fast forward two months of intermittent CELs that would pop up and go away. I returned the jeep to the dealer a few days ago with a consistent CEL. Can see the misfire codes and the engine is now being taken apart. No telling what the issue is but very frustrating having had the car for 3 months and now in the shop for a third time with zero success.
Third times the charm? Who knows…should’ve stuck with a wrangler.

Sorry to hear. I'm taking another trip to FL tomorrow (600+ miles) Last trip had a flashing CEL that went off after a few minutes. Never ran bad and haven't had an issue since we got home last week. Wouldn't the Wranglers have the same issues since they're using the same engine? I hope they can fix what's causing yours.

 

[Pglover91]

Sorry to hear. I'm taking another trip to FL tomorrow (600+ miles) Last trip had a flashing CEL that went off after a few minutes. Never ran bad and haven't had an issue since we got home last week. Wouldn't the Wranglers have the same issues since they're using the same engine? I hope they can fix what's causing yours.

Hmm, mine definitely made it a few long trips before issue again as well. Not saying it’ll happen to you but who knows. Lol yeah no the wrangler was more so because I had 3 prior with zero issues!

 

[Snook]

Hmm, mine definitely made it a few long trips before issue again as well. Not saying it’ll happen to you but who knows. Lol yeah no the wrangler was more so because I had 3 prior with zero issues!

This is my 4th Jeep, the others were all Wranglers, 2 had the inline 4.0 6cyl and the other two had the 2.4 inline 4cyl. No issues at all with any of them. The Gladiator is my first with the Pentastar V6. I'm surprised an engine that has been around as long as the Pentastar would start having issues.

 

[ShadowsPapa]

Have heart - I know it sucks to be the one, or one of the few, with an issue, but there's hope because there's a better chance of not having the issue.

We are on our 2nd Grand Cherokee with the same engine - 3.6 ESS, VVL, VVT
Zero issues other than a misfire at 900 miles due to spark plugs. Resolved pretty quickly by the dealer..
I'm now approaching 27,000 miles (and 31 months) on my JT - no misfires, no rattles, no pings, runs smooth and is so quiet I almost forget to shut it off at times.

So there are 3 Jeeps, all with the 3.6 with VVL and VVT and no misfires other than the 2021 with spark plug issues before it's 1,000 mile mark.

But then maybe these are defects, flukes, and weren't supposed to turn out this way?
Maybe the soil here is protected by those who lived here 3,000 years ago?

 

[bkmorgan64]

Purchased a 2022 Gladiator Rubicon 8 weeks ago. 4weeks ago the CEL light cam on at 311 miles. Took it to the dealer immediately. Its still there 4 weeks later. P0301 and the P0300 code. Dealer hasn't a clue on what's causing the issue. Corporate engineers are now involved trying to figure it out. Not too pleased with the whole situation right now. Making payment on a 60K vehicle and cant even drive it. I am going to guess the build date was early 2022 or late 2021. Being at the dealer, i cant get to it

Picked it up 3 weeks ago yesterday. Put about 500 miles on it and the light came back on July 3rd. The have it back. No explanation on the misfires first time in. This time it showed p0300 and on the U Connect app it showed an electronic throttle control issue.. There are no codes in the ecu for the ETC....shaking my head

 

[GrubbyBaja]

Build date: 10/2019 Rubicon, 6MT, stock.
Mileage when it first occurred: 23,500
How many times has it occurred: This was the 3rd time. 1st time @ ~12,000 miles; 2nd time @ 19,500 miles.
What exact codes did it throw: Had my OBD reader in the console, pulled it out and plugged it in while engine was still running and check engine light was flashing. 2 codes: P0303, Cylinder 3 misfire and P2308, Ignition Coil 'C' Secondary Circuit.
Is the issue on going? Unknown
If so, what has been done to try to solve the issue? Nothing yet other than to check/seat all relays/fuses in fuse block.
Was the issue ever fully resolved? Unknown
Description of misfire: Driving along a SE Alabama 2-lane highway (minor hills to level) at approximately 55 mph, 5th gear, with cruise control set. Outside air temp ~80F, oil temp ~190F, coolant temp ~194F, voltage ~14.3, all of which are normal readings for my vehicle. Cruise control deactivated, ASS light illuminated, and a notable misfire was noticed as soon as I gave it throttle to maintain speed. 3-5 seconds after noticing the misfire, the yellow check engine light began flashing. Maintained 55 mph in 5th gear with a continuous misfire (felt like loss of a single cylinder as the vibration was a constant frequency). Pulled out my OBD reader and plugged it in and read codes (while maintaining 55 mph). After approximately 2 minutes, with vehicle still misfiring and check engine light flashing, pulled off road and shut down vehicle. Restarted vehicle and everything was normal. Both previous instances were identical except I kept driving and the misfire stopped after 2-3 minutes, check engine light stopped flashing and check engine light remained off.

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