4 of us at Work have Gladiators, buddies 3rd time in shop. Misfire Question.

[StripeUSA]

Oh boy. Now there’s something to look forward to. I’m 71 and usually only drive it literally on Sundays, it should take a while to get to that point, at least until the “new” wears off. I figure it only needs to last as long as me. So I’ll just keep driving my JK daily. Hope to do some light off reading next month. These are my first Jeeps (not counting my Army career).

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[ShadowsPapa]

Got my Gladiator back next day, turned out to be simply a bad plug. Evidently uses some Champion “hi-tech” plugs factory installed in these engines. Next oil change, want to replace them all with Bosch plugs, if it doesn’t become warranty issue. Any plug recommendations?

You have a 2021 model year. We had a 2021 MY Grand Cherokee with 3.6 Misfire at about 800 miles.
Shorten the long story, after showing dealership a report including freeze frame info and proof it was an ignition misfire, they dug and found a TSB pointing to bad plugs in certain 2021 model year 3.6s
They replaced all 6 plugs and it was fine after that.
Any company can have a bad batch of anything. Heck, even NASA has failed now and then.

Can’t even imagine the labor cost for what should be a relatively quick, easy job.

Took the dealership "an afternoon" on our GC back in 2021. Warranty, luckily.


Stuff happens. Generally speaking the plugs designed for these engines are quite good - imagine the heat they have to withstand, the pressures, and the erosion they must resist from the spark jumping. They aren't like the plugs in our old V8s they have a platinum tipped ground electrode, iridium-tipped center electrode and a reach specific for the PUG Pentastar.

 

[Pedal Metal]

I've searched the threads for something similar to my issues with my 2022 3.6 with just under 10K miles which is in the shop now, because I noticed a very slight roughess to the idle when in park. It was so faint that I didn't know if it was in my head or not until I went to the dealership and asked for keys to sit in a new 3.6 while it idled, and it confirmed that mine wasn't as smooth as the new 3.6.
So, yesterday, after a week in the shop with an open STAR case, I was informed that they traced this down to either an issue with the head gasket / valve seats for cylinder 2. The service advisor who I've had a good relationship with and is now the manager shared that there is a very faint amount of rust in that cylinder and they had already ordered a replacement head which may be in today. I expressed some concern about the potential wear with the cylinder wall and rings and even asked if the cylinder head should be honed. The advisor / manager said they're not set up to hone cylinders, so I asked if that was a crazy question or if any other shops would do anything like that at this point which he answered that he didn't think so and Jeeps prescribed fix is a new head gasket and head.
Now, here is misfire backstory. I first experienced a Check Engine Light present around 1.6K miles, but the code didn't store. Then, at 1.9k miles another CEL with a P0300 code. At 2K miles, another code, but they couldn't reproduce it in the shop or find an issue and changed the oil to examine it. Another P0300 at just under 4K, with an answer that there's nothing else they can really do, but clear the code until Jeep sends out a fix for the P0300 issue that was plaguing some of us last fall and winter. Then, at 6K they installed a new PCM code update. However, even after the fix, I just couldn't put my finger on it, but I sensed something wasn't quite right. So, I'd occasionally stop in the dealer to have my codes checked. Either 2 or 3 times over the last few thousand miles. Hence, I've felt like I'm baby sitting their problem and it turns out there was a problem! HOT DARN!
Well, throughout that earlier experience, I was in touch with Jeep Cares. At one point, they offered some type of number (CVI?) to buy a new vehicle at employee pricing, but I was never that impressed with that and told them I might keep this jeep well past the original warranty and asked that they extend coverage if there is a latent issue that persists from this and they did. So the matter seemed closed for a time.
Well, I've since reconnected with J.C. again and I brought up a buy back after mentioning that I believe this meets all the requirements for a particular law about fruits. I've since spoken with a representative and they said they would be in touch after a 2 day review.
Let me just say, that I can appreciate the difficult spot they're in to isolate the root cause of these types of issues, but this collective experience has robbed a bit of joy from far to many of my days present ones included (no fun sunrider flipped back jeep rides for more than a week and no loaner car to boot).
I'll also add, that I've never smelt any type of coolant from the exhaust, but maybe that's because it was just a such a tiny bit that was getting past the gasket / valve seats.
Still, rust in the cylinder, likely some additional ring wear and maybe some coolant emulsification within the oil over the past so many miles. Perhaps, it's all too minimal to care, but I do.

 

[Maximus Gladius]

I've searched the threads for something similar to my issues with my 2022 3.6 with just under 10K miles which is in the shop now, because I noticed a very slight roughess to the idle when in park. It was so faint that I didn't know if it was in my head or not until I went to the dealership and asked for keys to sit in a new 3.6 while it idled, and it confirmed that mine wasn't as smooth as the new 3.6.
So, yesterday, after a week in the shop with an open STAR case, I was informed that they traced this down to either an issue with the head gasket / valve seats for cylinder 2. The service advisor who I've had a good relationship with and is now the manager shared that there is a very faint amount of rust in that cylinder and they had already ordered a replacement head which may be in today. I expressed some concern about the potential wear with the cylinder wall and rings and even asked if the cylinder head should be honed. The advisor / manager said they're not set up to hone cylinders, so I asked if that was a crazy question or if any other shops would do anything like that at this point which he answered that he didn't think so and Jeeps prescribed fix is a new head gasket and head.
Now, here is misfire backstory. I first experienced a Check Engine Light present around 1.6K miles, but the code didn't store. Then, at 1.9k miles another CEL with a P0300 code. At 2K miles, another code, but they couldn't reproduce it in the shop or find an issue and changed the oil to examine it. Another P0300 at just under 4K, with an answer that there's nothing else they can really do, but clear the code until Jeep sends out a fix for the P0300 issue that was plaguing some of us last fall and winter. Then, at 6K they installed a new PCM code update. However, even after the fix, I just couldn't put my finger on it, but I sensed something wasn't quite right. So, I'd occasionally stop in the dealer to have my codes checked. Either 2 or 3 times over the last few thousand miles. Hence, I've felt like I'm baby sitting their problem and it turns out there was a problem! HOT DARN!
Well, throughout that earlier experience, I was in touch with Jeep Cares. At one point, they offered some type of number (CVI?) to buy a new vehicle at employee pricing, but I was never that impressed with that and told them I might keep this jeep well past the original warranty and asked that they extend coverage if there is a latent issue that persists from this and they did. So the matter seemed closed for a time.
Well, I've since reconnected with J.C. again and I brought up a buy back after mentioning that I believe this meets all the requirements for a particular law about fruits. I've since spoken with a representative and they said they would be in touch after a 2 day review.
Let me just say, that I can appreciate the difficult spot they're in to isolate the root cause of these types of issues, but this collective experience has robbed a bit of joy from far to many of my days present ones included (no fun sunrider flipped back jeep rides for more than a week and no loaner car to boot).
I'll also add, that I've never smelt any type of coolant from the exhaust, but maybe that's because it was just a such a tiny bit that was getting past the gasket / valve seats.
Still, rust in the cylinder, likely some additional ring wear and maybe some coolant emulsification within the oil over the past so many miles. Perhaps, it's all too minimal to care, but I do.

It’s good to care. Ask they folks at the top of the roster if they care that people buy their products. Once they sell it, the customer should care for that product followed by the service department. It says a lot about you and a lot about the service department.

Back in February 2021, I bought my JTR and at 1000k kms I did my first oil change and oil analysis. Report came back I had “trace” amounts of glycol in the oil and I was to monitor it.
I did very early oil changes - 6 in 32k kms, all showing ALERT glycol contamination in the oil and I was having to top up the coolant bottle 1 ounce every 1000 kms. At 16k kms I misfired in cylinder 2 and when the truck went in, I also took in all 3 analysis reports showing the internal coolant leak. The tech cared enough to write about it in his notes on the service report which went to NORM (FCA Engineer) There was NO interest to investigate the leak and NORM never provided any feedback from FCA on it.

Service advisor then told me “it’s normal for coolant to be in the oil”. Was he trying to piss me off?? Anyway, the typical repairs were done, …change some rockers and the cam shaft and call it done.

Tons of mechanical drama to follow and my insurance paid for a new engine and transmission in 2022. About 30k kms later and all is good and oil reports don’t show any glycol contamination.

At the time I had the new engine ordered, the service manager said it would be the upgraded one not screwed up like the old batch of engines. See if you can find the engine manufacturer date. Sometime in 22 was the upgrade made to them.

 

[ShadowsPapa]

The service advisor who I've had a good relationship with and is now the manager shared that there is a very faint amount of rust in that cylinder and they had already ordered a replacement head which may be in today. I expressed some concern about the potential wear with the cylinder wall and rings and even asked if the cylinder head should be honed. The advisor / manager said they're not set up to hone cylinders, so I asked if that was a crazy question or if any other shops would do anything like that at this point which he answered that he didn't think so and Jeeps prescribed fix is a new head gasket and head.

You can't hone cylinders without a complete engine tear-down. No, don't worry about the cylinder walls. They don't rust in these (I see you said cylinder head - you don't hone a head, only the cylinder in the block)

They are correct - head and gasket.

Why would there be wear in the cylinder or on the rings? You'd have to run a fair amount of coolant through for a problem there.

Still, rust in the cylinder, likely some additional ring wear and maybe some coolant emulsification within the oil over the past so many miles. Perhaps, it's all too minimal to care, but I do.

Aluminum blocks don't rust. Coolant prevents rust - not cause it. Think about it - the whole system is filled with coolant and it doesn't rust so why would the other side rust? (and again, it's aluminum)
I've dealt with this exact thing for decades - worse than what you have, and it's never been a problem even with CAST IRON blocks and heads.
I've also seen crankcases drained of what looks like an over-priced Starbucks drink and not have issues.
Many years of cracked heads, bad gaskets and so on and it's always been fix it and move on.

I also bet a steak dinner they are not only not equipped to hone, but no one there knows HOW to properly do it - I'd not want a dealership shop to do what they don't ever do anyway. They replace, not rebuild.
I am equipped to not only bore, but properly hone in my shop - but if this was mine and I was doing it myself, I'd clean the cylinder out, swap heads, change the oil and move on.
You don't want them taking the whole engine apart to hone - not in that shop. Honing leaves a lot of grit residue in the block and you need to wash it out thoroughly with soapy water and rinse after honing.
Ya want them doing that and risking that getting through the rest of the block?
At the VERY LEAST they'd have to pull the pan but then that stuff drops onto the crankshaft and other rod journals.

The fact you aren't dealing with large coolant level drops and don't see white out the exhaust or smell coolant (difficult on these twin cat systems) also says - you are barking up a tree that has nothing in it.

 

[ShadowsPapa]

At the time I had the new engine ordered, the service manager said it would be the upgraded one not screwed up like the old batch of engines. See if you can find the engine manufacturer date. Sometime in 22 was the upgrade made to them.

What upgrade??????
Not sure I'd go by what a service manager says.

If there was such a thing, we've got a couple of forum members who are real life techs and know stuff and could tell if that was a fact, or BS from someone in a shop trying to make a customer happy.

 

[Maximus Gladius]

What upgrade??????
Not sure I'd go by what a service manager says.

If there was such a thing, we've got a couple of forum members who are real life techs and know stuff and could tell if that was a fact, or BS from someone in a shop trying to make a customer happy.

Whatever was causing all the misfires (parts put in wrong or upside down) was changed and put in right. I read about it here.

 

[ShadowsPapa]

Whatever was causing all the misfires (parts put in wrong or upside down) was changed and put in right. I read about it here.

If that was about lash adjusters, that's been sort of debunked. Found out no, it never happened.
Misfires have been as diverse causes as there's been Jeeps. Hard to say "if you have a misfire, it's likely this" because it's been all over the map.
In short, there wasn't really a parts issue, that was a mistaken notion. Others later proved the parts couldn't be switched around, they didn't fit.

 

[Maximus Gladius]

If that was about lash adjusters, that's been sort of debunked. Found out no, it never happened.
Misfires have been as diverse causes as there's been Jeeps. Hard to say "if you have a misfire, it's likely this" because it's been all over the map.
In short, there wasn't really a parts issue, that was a mistaken notion. Others later proved the parts couldn't be switched around, they didn't fit.

Would you say, from when threads were started about misfires, I think you got that one going, there were more misfires with 2020/21 engines and then as we move through 22 and 23, misfires have taken a turn for the better?

 

[ShadowsPapa]

Would you say, from when threads were started about misfires, I think you got that one going, there were more misfires with 2020/21 engines and then as we move through 22 and 23, misfires have taken a turn for the better?

Cam issues seem to have been resolved. They are far more rare. Cam grinds, perhaps hardening, and reprogramming. A lot of the misfires were resolved with PCM updates.
My 2022 had some nasty misfire issues under extremely specific conditions and that was also a PCM thing - it hadn't learned CCDIFF. A forced relearn resolved all misfires. Smooth as silk now.
I'd say that most of the early issues were more cam.

They have more recent TSBs out related to lash adjusters for 2022 and 2023 model year Jeeps (any with the 3.6) related to ticking, and only on one side.
And looking at this - it supports my thinking that ticking and misfires have no year, no range, and no single fix. It varies and we can't say that any built after a certain point won't have issues, or that "it's always xxx part if......."

This is one of the latest -
This bulletin applies to RU, JL ,JT, DT, WL and WD
vehicles built on or after June 03, 2022 (MDH
0603XX) and on and before October 07, 2022 (MDH
1007XX)

So it includes my June 2022 built JT but so far it's quiet as any I've heard if not quieter.

So if you want a perfect 3.6, get one built after October 7th 2022 but then there will likely be a TSB for those, too LOL.

 

[Maximus Gladius]

Cam issues seem to have been resolved. They are far more rare. Cam grinds, perhaps hardening, and reprogramming. A lot of the misfires were resolved with PCM updates.
My 2022 had some nasty misfire issues under extremely specific conditions and that was also a PCM thing - it hadn't learned CCDIFF. A forced relearn resolved all misfires. Smooth as silk now.
I'd say that most of the early issues were more cam.

They have more recent TSBs out related to lash adjusters for 2022 and 2023 model year Jeeps (any with the 3.6) related to ticking, and only on one side.
And looking at this - it supports my thinking that ticking and misfires have no year, no range, and no single fix. It varies and we can't say that any built after a certain point won't have issues, or that "it's always xxx part if......."

This is one of the latest -
This bulletin applies to RU, JL ,JT, DT, WL and WD
vehicles built on or after June 03, 2022 (MDH
0603XX) and on and before October 07, 2022 (MDH
1007XX)

So it includes my June 2022 built JT but so far it's quiet as any I've heard if not quieter.

So if you want a perfect 3.6, get one built after October 7th 2022 but then there will likely be a TSB for those, too LOL.

I would say if nothing was done, the stats on misfires would remain the same. If we are seeing a down tick in these mechanical issues, somethings been down. Hence I call it an “upgrade” what ever that looks like. If the internals of the 22 to 23 3.6’s are different to address the misfire issue, then upgrades are done and results would be less misfires in the stats. My uneducated (and I mean that) opinion anyway.

 

[ShadowsPapa]

I would say if nothing was done, the stats on misfires would remain the same. If we are seeing a down tick in these mechanical issues, somethings been down. Hence I call it an “upgrade” what ever that looks like. If the internals of the 22 to 23 3.6’s are different to address the misfire issue, then upgrades are done and results would be less misfires in the stats. My uneducated (and I mean that) opinion anyway.

That upgrade could be simple PCM programming. The cam issues were mostly taken care of by the 2021 model year but that's not an upgrade, that's a process change in all likelihood.
No internals were changed from what I'm seeing. Remember, misfires can be spark plugs or PCM programming.
2021 saw misfires due to spark plugs. That was fixed - but it's not an upgrade, it's a bad batch of spark plugs. 2022 saw CCDIFF issues causing misfires - that's not an upgrade or change to anything as far as engine parts - that's a PCM thing.
I'd bet that if you looked, the lash adjusters and so on are the same 2020 to 2023.
We can't be lumping misfires all onto the physical engine! Could be coil pack, spark plug, injectors, PCM programming, and so on.
The only down-tick was cams dying. That's not been happening so much in years after 2020.
And again, that's not necessarily fixed with any upgrade - that's likely fixed by a process issue - cam hardening or similar.
There have been at least 3 PCM updates for misfires that I'm aware of - so is that an engine upgrade to fix misfires?
These are running on the bleeding edge, stoic more than most other engines, that means the slightest little goof in programming or control of the cams and you get misfire. That's PCM, not hardware.
Yes, if I was to need a replacement engine, I'd want one from 2021 and later due to the cam issues of 2020, but otherwise, I'd take anything 2021 and later. OR, a 2020 with new cams and followers. That's only because of process issues more than anything.

 

[Pedal Metal]

You can't hone cylinders without a complete engine tear-down. No, don't worry about the cylinder walls. They don't rust in these (I see you said cylinder head - you don't hone a head, only the cylinder in the block)

They are correct - head and gasket.

Why would there be wear in the cylinder or on the rings? You'd have to run a fair amount of coolant through for a problem there.



Aluminum blocks don't rust. Coolant prevents rust - not cause it. Think about it - the whole system is filled with coolant and it doesn't rust so why would the other side rust? (and again, it's aluminum)
...

Thanks for your answers, I did accidently write "hone head", but I really did mean "cylinder wall":

"...I expressed some concern about the potential wear with the cylinder wall and rings and even asked if the cylinder head should be honed. The advisor / manager said they're not set up to hone cylinders..."

As for rust in the cylinder, I recall hearing something along the lines of: "there is a very faint amount of rust in that cylinder", maybe he meant something else, but that's what he described. So, I presumed the aluminum block had a steel liner in the cylinder. However, whatever he was attempting to describe, I with some past shade tree engine swapping and some, but minimal tuning experience am admittedly outside of my depth. As I really don't know how much engine mechanical surface wear comes from however much coolant leak over however much length of time.

So, thanks for some reassurance that this really isn't cause for concern.

 

[56cbr600rr]

Update on my buddies JTR. They did lifters on the other side. Also, the Tech mentioned that both sides got new cams. Been three days, no lights and he says it seems to idle smoother.

so far so good and fingers crossed

 

[ShadowsPapa]

Update on my buddies JTR. They did lifters on the other side. Also, the Tech mentioned that both sides got new cams. Been three days, no lights and he says it seems to idle smoother.

so far so good and fingers crossed

With new cams it means new followers (rockers)
If they did the lash adjusters (what some still call lifters) I wonder if it was due to the TSB on ticking and codes that specifies to replace the lash adjusters on the side that ticks.

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