3.6 Pentastar Misfire on Cylinders 1, 3, & 5

Well, after everything said and done, I ended up buying a high end ODB2 tool - xtool d8 and performed Cam/Crank relearn and now most of misfires went away. Now from time to time I get cyl 2 misfire, but it does not trigger check engine and still produces good trip record. I am just wondering why dealer could not perform same function. Even with this fix there still an issue, but something I can resolve over time. The xtool allows to read live data, showing cams position and difference between desired and actual all withing 5% range, injector pulse width, etc. Interestingly - cylinders with lower pulse with on injectors are the ones misfiring. I wonder if there is a way to re-code injectors to same pulse width....not sure how to do this.
 
  • Like
Reactions: mrjp and Vman
Well, after everything said and done, I ended up buying a high end ODB2 tool - xtool d8 and performed Cam/Crank relearn and now most of misfires went away. Now from time to time I get cyl 2 misfire, but it does not trigger check engine and still produces good trip record. I am just wondering why dealer could not perform same function. Even with this fix there still an issue, but something I can resolve over time. The xtool allows to read live data, showing cams position and difference between desired and actual all withing 5% range, injector pulse width, etc. Interestingly - cylinders with lower pulse with on injectors are the ones misfiring. I wonder if there is a way to re-code injectors to same pulse width....not sure how to do this.

I feel like all of us JK owners could use one of those.

Im guessing you didn't go in and do all the lifters and rocker followers yet? Im really curious if Dave's suggestion will "fix" the code.
 
  • Like
Reactions: mrjp and Vman
Not yet - I want to drive it a bit and see the issue come back - I do have all of the rockers and lifters, solenoids and actuators ready ;-). The fact that cam/crank re-learn changed the whole dynamic of misfire - gives me hope. I am also reaching out to pine hollow diagnostics - Ivan has a great channel on youtube - and he has right mind-set and experience to diagnose this issue - I actually picked up couple of tricks from him. Will keep you posted.
 
Not yet - I want to drive it a bit and see the issue come back - I do have all of the rockers and lifters, solenoids and actuators ready ;-). The fact that cam/crank re-learn changed the whole dynamic of misfire - gives me hope. I am also reaching out to pine hollow diagnostics - Ivan has a great channel on youtube - and he has right mind-set and experience to diagnose this issue - I actually picked up couple of tricks from him. Will keep you posted.

Maybe you could get an Ivan/Eric O. consult ;)

Sounds like something they'd love.

props for your refuse-to-lose on this!
 
Solved - ISH ;-)

So - the misfire is solved - together with about dozen of other code like air-to - fuel ratio disbalance.
About 6 different codes were caused by.....incorrect O2 Sensors!!!!!!!

SELF INFLICTED - but How you ask? See the screenshot from RockAuto for 2013 jku O2 Sensors:

1648846907766.png



As you can see - recommended and hearted sensor is Bosch 15510, which according to RockAuto fits into any of the upstream/downstream configurations. At least that's how I read it. Though if I paid better attention I would see that other o2 sensors have 2 sensor part numbers for different locations. I though ECM is smart enough to figure out location through wiring. WRONG!!!!

Ended up buying NTK- OEM and placing them into exactly defined locations - and poof problem solved.

1648847209891.png



Now, I still have P0018 Code crank/Cam bank 2 mis-allignment. So either sensor or maybe the actual chain jumped - have to figure out how to test. But overall jeep runs perfect. below is what OBD@ tool shows:
1648849070073.png


Will try Ivan - if he can take a look at numbers and if it makes sense to him.

Lets see.

1648847186908.png
 
  • Like
Reactions: Bwest and mrjp
M Duncan,

I just read your initial post and I am having the same exact issues with my Dodge Durango 3.6 on cylinders 1,3 mostly and sometimes #5. I too want to keep my 2011 Durango that currently has 245K miles that I have owned since new. The vehicle has been taken very good care of so I want to keep her. I new keep getting the CEL with the #3 and sometimes #1 and random #5 misses. The misses on these individual cylinders are never at the same time. The engine misses mostly at idle or while driving not under load. The left side cylinder head was replaced under the recall so luckily no issues with 2, 4 or 6 cylinders.

I have also changed coils, plugs, rocker arms, lifters, PCV, Injectors, (used) throttle body, upper and lower intake gaskets, O2 sensors. I have a BlueDriver scanner that can read the data from the PCM. I will live graph the O2 levels like Xactly had suggested to see if it's a O2 sensor issue.
My thoughts were headed towards an electrical short or a vacuum leak. I went ahead and changed all the intake gaskets to no avail. I just got an electrical diagram so I will start that soon.

If of this doesn't work I am waiting on an AESwave UScope to verify what might be causing the miss but delivery is 2 months out. I am just learning how to use an oscilloscope but was thinking about a bi-directional scan tool. Thoughts were picking up a TopDon tool and I was hoping that it might help.

Since I retired I have plenty of time to play with this but after messing with the vehicle for 5 months it's getting old. Please let me know if you have found the cure for your Jeep!

Thanks
Sketchmo
 
  • Like
Reactions: Vman
M Duncan,

I just read your initial post and I am having the same exact issues with my Dodge Durango 3.6 on cylinders 1,3 mostly and sometimes #5. I too want to keep my 2011 Durango that currently has 245K miles that I have owned since new. The vehicle has been taken very good care of so I want to keep her. I new keep getting the CEL with the #3 and sometimes #1 and random #5 misses. The misses on these individual cylinders are never at the same time. The engine misses mostly at idle or while driving not under load. The left side cylinder head was replaced under the recall so luckily no issues with 2, 4 or 6 cylinders.

I have also changed coils, plugs, rocker arms, lifters, PCV, Injectors, (used) throttle body, upper and lower intake gaskets, O2 sensors. I have a BlueDriver scanner that can read the data from the PCM. I will live graph the O2 levels like Xactly had suggested to see if it's a O2 sensor issue.
My thoughts were headed towards an electrical short or a vacuum leak. I went ahead and changed all the intake gaskets to no avail. I just got an electrical diagram so I will start that soon.

If of this doesn't work I am waiting on an AESwave UScope to verify what might be causing the miss but delivery is 2 months out. I am just learning how to use an oscilloscope but was thinking about a bi-directional scan tool. Thoughts were picking up a TopDon tool and I was hoping that it might help.

Since I retired I have plenty of time to play with this but after messing with the vehicle for 5 months it's getting old. Please let me know if you have found the cure for your Jeep!

Thanks
Sketchmo

I commend you for being so incredibly ambitious and going in-depth to correct your issues. Learning never hurts and it's surely keeping you busy. I would have lost my f*^%ing mind.

Hope you figure it out and school us in the process. ✌️
 
  • Like
Reactions: Vman
M Duncan,

I just read your initial post and I am having the same exact issues with my Dodge Durango 3.6 on cylinders 1,3 mostly and sometimes #5. I too want to keep my 2011 Durango that currently has 245K miles that I have owned since new. The vehicle has been taken very good care of so I want to keep her. I new keep getting the CEL with the #3 and sometimes #1 and random #5 misses. The misses on these individual cylinders are never at the same time. The engine misses mostly at idle or while driving not under load. The left side cylinder head was replaced under the recall so luckily no issues with 2, 4 or 6 cylinders.

I have also changed coils, plugs, rocker arms, lifters, PCV, Injectors, (used) throttle body, upper and lower intake gaskets, O2 sensors. I have a BlueDriver scanner that can read the data from the PCM. I will live graph the O2 levels like Xactly had suggested to see if it's a O2 sensor issue.
My thoughts were headed towards an electrical short or a vacuum leak. I went ahead and changed all the intake gaskets to no avail. I just got an electrical diagram so I will start that soon.

If of this doesn't work I am waiting on an AESwave UScope to verify what might be causing the miss but delivery is 2 months out. I am just learning how to use an oscilloscope but was thinking about a bi-directional scan tool. Thoughts were picking up a TopDon tool and I was hoping that it might help.

Since I retired I have plenty of time to play with this but after messing with the vehicle for 5 months it's getting old. Please let me know if you have found the cure for your Jeep!

Thanks
Sketchmo

245k miles is a heck of a lot of miles, so you could very well be dealing with engine internals.

One valve not working correctly, or a timing chain or on and on. Lots of potential problems there.

Probably cheaper to just pull the engine and stick a low mileage one in.

That said, I think it's worth noting that you got 245k miles out of your Pentastar. Not too shabby.
 
  • Like
Reactions: Threepointsix
@Vman sure is a heck of a lot of miles but still, not a Jeep Wrangler 3.6, it's a Durango 3.6 😆😆

Funny enough, I watched a video on YT yesterday and the tech said that he himself has never had to fix a ticking issue on a 1500 with the 3.6!

Here ya go:
 
@Vman sure is a heck of a lot of miles but still, not a Jeep Wrangler 3.6, it's a Durango 3.6 😆😆

Funny enough, I watched a video on YT yesterday and the tech said that he himself has never had to fix a ticking issue on a 1500 with the 3.6!

Here ya go:

LoL that one flew right over my head!

That's still a lot of miles for any engine though!
 
  • Like
Reactions: Threepointsix
245k miles is a heck of a lot of miles, so you could very well be dealing with engine internals.

One valve not working correctly, or a timing chain or on and on. Lots of potential problems there.

Probably cheaper to just pull the engine and stick a low mileage one in.

That said, I think it's worth noting that you got 245k miles out of your Pentastar. Not too shabby.
I forgot to mention I ran a leak-down test and all the cylinders were in specs. 90lbs all cylinders had a 0-2lb drop at most. When I pulled the valve covers the internals were exceptionally clean and with little wear on the cams. I'm still going to check for an electrical short to see if I get somewhere. I test drove the truck yesterday and the miss is getting worse once it warmed up. It might be a PCM issue as well...l hope not. Thanks for your reply!
 
  • Like
Reactions: mrjp
Solved - ISH ;-)

So - the misfire is solved - together with about dozen of other code like air-to - fuel ratio disbalance.
About 6 different codes were caused by.....incorrect O2 Sensors!!!!!!!

SELF INFLICTED - but How you ask? See the screenshot from RockAuto for 2013 jku O2 Sensors:

View attachment 120881


As you can see - recommended and hearted sensor is Bosch 15510, which according to RockAuto fits into any of the upstream/downstream configurations. At least that's how I read it. Though if I paid better attention I would see that other o2 sensors have 2 sensor part numbers for different locations. I though ECM is smart enough to figure out location through wiring. WRONG!!!!

Ended up buying NTK- OEM and placing them into exactly defined locations - and poof problem solved.

View attachment 120883


Now, I still have P0018 Code crank/Cam bank 2 mis-allignment. So either sensor or maybe the actual chain jumped - have to figure out how to test. But overall jeep runs perfect. below is what OBD@ tool shows:
View attachment 120884

Will try Ivan - if he can take a look at numbers and if it makes sense to him.

Lets see.

View attachment 120882
This whole feed has been very informative, I have everything off my 2013 Jeep Wrangler JKU 3.6 (166k miles) engine right now…I did have a misfire in 5, but it went away after I got rid of the shell fuel my husband put into it…but I went ahead and changed out the injectors, because I was changing out the oil cooler filter housing and oil pressure& temp sensors, I have did spark plugs and coils not long ago, but gunna change out the plugs again since I’m here…I’m changing out the rockers and lifters also, got a tick after the oil cooler started leaking, I’ve done the PCV, super flushed it (my heat was working to well, it’s good now) but it’s been going in and out of limp mode, and getting the dreaded P0731… , I’ve already changed the TSS, fluid, and filter, gaskets, pin plug, and no difference…i changed the Crank before but now reading I need to relearn it…I have a scan tool so I can do that, but was just doing my research and came across this feed, and wanted to say thank you! I think I know exactly what I need to do now…and im pretty sure im going to go ahead and do all the O2’s as well…I know it’s been a while but if you see this, thank you for this post, this has helped me make sense of things…and I really hope you got that light off! I truly feel your frustration! Thanks again!
-Nessi
Tennessee
 
I just read all 6 pages of the issues and I, too have the 1,3,5 cylinder misfire at idle. I have a JScan tool and can watch it show misfires while at idle. I installed Accel coils and new spark plugs and noticed that the misfires still happen intermittently - not always cylinder 3 having the most misfires, etc.. Recently, I swapped out my O2 sensors with the Bosch ones because I was having O2 engine codes. Those codes went away and it drove fine with no O2 codes showing up. I also had a small evaporations leak code with I fixed with some silicone adhesive on the front tube on top of the intake( loose rubber hose fitting & leaking). I will order a new set of O2 sensors and replace them.
What I neglected to tell you all is this is on a new crate engine from Mopar with less than 10k miles on it. My original engine had a bad cylinder oil rings and I couldn't finance the Hemi swap so I went with another 3.6 engine installed at the dealership for $8k. They swap out all external parts from old engine to the new one. I knew the O2 sensors were bad from the oil leaking into the exhaust system from the old engine. So I purchased on Rockauto the Bosch ones. I will try the factory O2 sensors and check back in with you all.
 
Did you use OEM spark plugs? The Accel coil could be your problem and also if you didn't use OEM plugs.

But since the problem is on the same bank it could also be the connector, maybe a bad pin in it.
 
  • Like
Reactions: BigAL07
Did you use OEM spark plugs? The Accel coil could be your problem and also if you didn't use OEM plugs.

But since the problem is on the same bank it could also be the connector, maybe a bad pin in it.
I checked the pins to make sure they were all the same length. The spark plugs were ngk. This misfire issue did not show up until I did the O2 sensor swap out. What are the odds of all 3 coil packs going bad on the same side of the engine and only at idle?
 
I checked the pins to make sure they were all the same length. The spark plugs were ngk. This misfire issue did not show up until I did the O2 sensor swap out. What are the odds of all 3 coil packs going bad on the same side of the engine and only at idle?

That's why I also suggested a problem in the wiring.
 
  • Like
Reactions: BigAL07
Hi Folks,

Looking for your expertise.

The problem: Random Misfires on cylinders 1,3,5 - Confirmed with Scanner
The Jeep: 2012 JKU 6-Speed, 108K miles
How long: I've been trying to fix this: 9 months

It's hard to feel the misfire when under throttle, but you can hear and feel the slight misfire trembles when at idle.

What I've tried so far:
- New Spark Plugs: (2 set's - 6 NKG & 6 Champion) Properly Gapped
- New Coils: MSD
- New O2 Sensors (all 4 - both sides)
- New Crankshaft Position Sensor
- New MAP Sensor
- All new Rocker Arms and Lifters on that bank (Cyl 1,3,5)
- New Camshaft Position Sensor
- New Injector on Cyl 5 = No change still misfiring
- New upper and lower o-rings for injectors
- New upper and lower o-rings for Lower and Upper Manifolds

Tests Completed:
- Leakdown Test Showed Normal
- Rotated Coils - No Change
- Rotated Plugs - No Change
- Camshafts inspection - no flat spots found

Additional Modifications Possibly Affecting Performance:
Mishimoto Oil Catch Can
Banks CAI
Odyssey Battery

Additional Fixes Completed on Motor:
- New Oil Pressure Sensor


Friends,
Please help. I love my jeep, and I want to drive it to 300k miles and drop in a Hemi and keep driving it.

(Wave),
Matt
Hi Matt!

I am having a very similar problem with my 2014 Wrangler.

The shop has been throwing parts at it for weeks and I could really use your opinion.

Could we chat about it? I am also in Denver if that helps!

Hope to hear from you soon.

Cole
 
Hi Matt!

I am having a very similar problem with my 2014 Wrangler.

The shop has been throwing parts at it for weeks and I could really use your opinion.

Could we chat about it? I am also in Denver if that helps!

Hope to hear from you soon.

Cole
Does everyone who is having these misfire codes all have a brittle wiring harness? Do we all have the PCM going bad on them? I would think that replacing working parts that are not throwing codes are an issue or would I be wrong in saying that if we have a P0300 code not other codes will appear? My next step is to remove the intake, inspect for mis alignment and bad intake gaskets and then re-install it to take out the air leak question. After this I will dive into the brittle wiring loom. I would like to run all new wires from the 1,3,5 injectors to the harness with both positive and ground wires to see if that makes a difference.
 
  • Like
Reactions: BigAL07