Survey- For those with misfire issues

[Vanishing Point]

How are these vehicles going to pass their Smog Checks when they are firing off these codes?

Sponsored

 

[Brojave22]

Yes.
That's the short answer.

Otherwise, the first time in July, it was dinging and flashing, then stopped flashing and then after a second or two, set it solid.

This time, a couple of days ago, it was dinging a little, flashed the CEL, then finally set it solid after it flashed for a while. The CEL went away on its own after a couple of shutdowns and restarts over the next day. It's been fine since.
it's very specific - drive it enough miles to get everything 100% warmed up.
Stop for maybe a meal, or some quick shopping, come out after 15-30 minutes and start it again and it MAY misfire. The CEL will flash, it will ding, and the CEL will finally come back on and stay.
It bucks and jumps - but if I "give it some gas", take it off idle into the mid-teens as far as RPM, it settles down or if you wait, it may settle down.
It's only idle or very low RPM and light load after sitting a few minutes. It's as if something gets warm from being shut down without fans running.
In the old days I'd call that "heat soak" when coolant temperatures are likely to jump due to the hot spots of the engine putting heat into the coolant but the coolant not being cooled by moving or the fans. Temperatures would actually rise way over the normal 190-200 degrees in older cars and trucks- maybe into the 230 or higher range where if you had a bad radiator cap the coolant would boil AFTER you shut it down because no more heat was removed from the coolant but hot engine parts were still heating the coolant in the block and heads.

hmm mine is doing the same, after a drive, letting it sit for a while then drive it, cel flashes then stays solid , cycle engine a few times and cel clears

 

[jebiruph]

https://www.google.com/search?q=site:JLwranglerforums.com+misfire

Thanks for your help, but a response like this post would have been even better. It's not conclusive, but it illustrates why I made the statement that "For some reason the JL did not have these misfire issues like the JT does".

Here is the result of a search for the word "misfire" in the title of threads in the jlwranglerforums
"Issues, Repairs, Warranty, TSB, Recalls " forum. 7 threads - 127 replies

Here is the result of a search for the word "misfire" in the title of threads in the jeepgladiatorforum "Issues, Repairs, Warranty, TSB, Recalls " forum. 17 threads - 1925 replies

 

[ShadowsPapa]

How are these vehicles going to pass their Smog Checks when they are firing off these codes?

It depends on the misfire event root cause. In a case like mine, warm it up good and run the tests. It would pass.
The event is rare and only happens under very specific conditions.
There's no common issue - 10 people with a misfire code could have 10 different reasons or causes, and the misfires could happen at different times under different conditions.
Take mine out now, take it to some test station, it's likely to pass - and not set the CEL. In fact, I went 4,000 miles and 2 months between misfire events.

People see the word "misfire" and even though even in the 1950s it could have had a dozen different causes, today people seem to think that every misfire has the same cause and happens the same way.
People need to stop this "hey, mine misfires too, what's the fix" junk.

 

[ShadowsPapa]

hmm mine is doing the same, after a drive, letting it sit for a while then drive it, cel flashes then stays solid , cycle engine a few times and cel clears

Seems that this specific sequence of events is a 2022 model year thing......... I keep trying to gather all the details and specifics I can.
I need to send a couple of my logs and freeze frames to Dave to see if he has ideas on why my LTFT is so different between bank 1 and bank 2.

 

[Lunentucker]

I find myself quite intrigued over having my single cylinder misfire issue remedied in about an hour.
They loaded the Z37 flash and they swapped the coil pack and plugs between my problematic cylinder (5) and the adjacent one (3).

Makes me wonder that perhaps some of these multiple cylinder misfires might be linked to whatever assembly failure didn't have something quite right on mine could be affecting multiple cylinders on others.

Keep in mind, these vehicles and components have been built and assembled during a pandemic that likely left lines short staffed for weeks at a time due to quarantine policies.
There has also been a chip manufacturing crisis on a global scale.
I've worked in manufacturing. When more orders pour in than the workforce can fulfill the lines are running more hours with less maintenance and bodies are thrown into production with less training and less oversight.

Keep in mind that these forums are rife with posts about loose bolts, parts falling off, and more.
Those are mechanical symptoms that can indicate systemic issues that can also affect electrical systems and ignition systems.

If they're not torquing brake caliper bolts and ball joints correctly at assembly, don't you think it's possible they're missing some things on the drive train?

Knowing what I know from my own experiences, if I was having a misfire issue right now, I would request that every plug and coil pack be removed, inspected, and reinstalled or replaced, as deemed appropriate.

If the dealership didn't want to do it I'd either do it myself or have a reputable garage do it for me.

I'll also continue to send oil samples in for analysis after every change, just to make sure that something unseen isn't a ticking time bomb.

 

[Kirk*Mojave]

Took the Truck to the dealer yesterday. They called me in the afternoon and basically said the vehicle is running fine (which it was other than the CEL coming on). They said that Jeep engineering is aware of the P0300 errors and is working to resolve it. They referenced a STAR case (See photo) and was told not to do any repairs. Service advisor stated that Jeep will issue a recall once a fix is found.

Hopefully a fix for this is around the corner

 

[Brojave22]

Seems that this specific sequence of events is a 2022 model year thing......... I keep trying to gather all the details and specifics I can.
I need to send a couple of my logs and freeze frames to Dave to see if he has ideas on why my LTFT is so different between bank 1 and bank 2.

So I did have a hole in the coolant reservoir that was fixed a few days after I brought it home, seeing your heat soak theory by chance did you have a coolant leak?

 

[ShadowsPapa]

So I did have a hole in the coolant reservoir that was fixed a few days after I brought it home, seeing your heat soak theory by chance did you have a coolant leak?

Nope, not that I've seen evidence of, although the coolant level did drop a bit after the first few hundred miles, it has not dropped since.

The heat soak thing is this - not related to leaks or troubles/problems/broken stuff -
The coolant temp as it flows by the sensor is typically close to the regulated temperature - the minimum being set by the thermostat. If it's saying 195 degrees, that's the coolant temperature and not necessarily the temperature of every part of the engine.
The gas is burned, BTUs released, and the cooling system works to keep up removing the BTUs that end up in the engine parts. Some parts will be cooler than that 195, some will be a heck of a lot hotter, but are prevented from getting WAAAY too hot by the constant heat transfer to the passing coolant.
Once the coolant flow stops, heat is no longer being removed from the coolant - it's not flowing through the radiator. It's sitting there, static.
However, the more hot engine parts will still continue to transfer heat to the coolant.
The parts that are say, 250 degrees or hotter, will transfer heat to other parts, and ultimately to the coolant that's just sitting there as well.
It's like when you cook with a cast iron skillet - you can turn the burner off, but the high heat in the skillet is still transferred to the food within so leaving the skillet on the hot burner and the food in the skillet can get you burned eggs even after the heat is off.
The coolant keeps getting heat from very hot engine parts, and that heat spreads through the coolant to to other parts making them hotter than they'd normally be.
The heat can't be removed from the coolant - it's sitting there. Conduction is spreading the heat from the extremely hot parts to the coolant, and to other parts. What's normally kept at 195 or cooler by circulating coolant can't be kept 195 or lower.

It's one reason why some muscle cars of the 60s and 70s couldn't be started after they were run, then shut off for a few minutes. And the cause of a car leaking coolant out the radiator cap back then - fine when running, leaks after being shut off for 10 minutes. Heat from the extremely hot engine parts made it to the coolant, making it hotter, raising the pressure in the cooling system, exceeding the 14 psi rating of the cap. (it's one reason why street/strip cars require a coolant recovery tank at the track)

I wonder if what's happening with these 2022 3.6s in the JT is that when they get hot (meaning thoroughly warmed up, operating temperature) and then shut off, the hotter parts by conduction transfer heat to other parts, and the coolant, then when you restart it, things are off kilter. Maybe injectors have gotten hotter, maybe O2 sensors, I'm just guessing, but I find it interesting that mine has ONLY had a problem after it was driven enough to make every single part of the engine hot - operating temperature, not TOO hot, but normally hot, then it's shut down for a few minutes, then restarted. And once the RPM is up or it's run for a few minutes, it's fine again.

I noticed that mine has very different long term fuel trims bank 1 compared to bank 2 and even the short term trims can be very different.
I'm not a pro like Dave, who WRITES these bloody things, but it just seems odd that one bank would be burning so very different than the other bank given they are part of the same engine breathing the exact same air at the same temperature, and burning the exact same gas from the same tank.


Long term fuel trim Bank 1;09/26/2022;14:02:26:03; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:26:99; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:27:95; -3.91000008583069
Long term fuel trim Bank 1;09/26/2022;14:02:29:19; -3.11999988555908
Long term fuel trim Bank 1;09/26/2022;14:02:30:21; -3.11999988555908
Long term fuel trim Bank 1;09/26/2022;14:02:31:57; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:32:73; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:34:21; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:35:32; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:36:39; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:37:41; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:38:49; -0.779999971389771
Long term fuel trim Bank 1;09/26/2022;14:02:39:48; -3.11999988555908
Long term fuel trim Bank 1;09/26/2022;14:02:40:91; -0.779999971389771


Long term fuel trim Bank 2;09/26/2022;14:02:26:13; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:27:08; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:28:05; 0
Long term fuel trim Bank 2;09/26/2022;14:02:29:29; 0
Long term fuel trim Bank 2;09/26/2022;14:02:30:32; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:31:66; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:32:91; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:34:32; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:35:47; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:36:49; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:37:50; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:38:57; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:39:57; 0.779999971389771
Long term fuel trim Bank 2;09/26/2022;14:02:41:01; 2.33999991416931
Long term fuel trim Bank 2;09/26/2022;14:02:41:94; -7.03000020980835
Long term fuel trim Bank 2;09/26/2022;14:02:43:04; -9.38000011444092
Long term fuel trim Bank 2;09/26/2022;14:02:44:10; -9.38000011444092
Long term fuel trim Bank 2;09/26/2022;14:02:45:11; -9.38000011444092
Long term fuel trim Bank 2;09/26/2022;14:02:46:13; -8.59000015258789
Long term fuel trim Bank 2;09/26/2022;14:02:47:11; -8.59000015258789
Long term fuel trim Bank 2;09/26/2022;14:02:48:64; -8.59000015258789
Long term fuel trim Bank 2;09/26/2022;14:02:49:69; -8.59000015258789
Long term fuel trim Bank 2;09/26/2022;14:02:50:71; -8.59000015258789

Still downloading info from my phone so I don't have the misfire screenshots yet........

 

[ShadowsPapa]

If you count the JL, it has been 5 model years already with reoccurring misfire issues of some sort or another. Do not let your Lemon Law rights lapse waiting on any fix. Just something to keep in mind.

These are very different misfire issues. Very specific circumstances, not random, but certain events have to happen in the right order at the right time.
This isn't a cold misfire, happens only when hot and after being shut down for a certain length of time (or for enough time for certain things to take place,. like heat transfer, etc.)
I count this, so far, as a 2022 MY specific issue, not to be lumped in with every other misfire.
We've not seen this type on any 2020 model year, and my recollection indicated it wasn't happening in this way in the 2021 MY, either.

So we can't say "my truck misfired, what's the fix" like everyone seems to love to do.
The misfires for the 2020 models were extremely different as far as root causes.
We've seen one sort of misfire in past model years resolved by PCM flash - I'd not be surprised to see something similar happen here due to the circumstances I've experienced personally, and all of my logging.

 

[ShadowsPapa]

I find myself quite intrigued over having my single cylinder misfire issue remedied in about an hour.
They loaded the Z37 flash and they swapped the coil pack and plugs between my problematic cylinder (5) and the adjacent one (3).

You have a 2021 model. The misfires there were extremely different.
The type that mirror my own appear to impact only 2022 models - and under extremely specific circumstances.
Yes, it's a misfire - but............ is every rattle the exact same shield or bolt?
Misfires can be fuel - injector, for example, even PCM injector control, voltages, dirt, whatever.
They can be ignition - PCM control over ignition, coil pack, spark plugs (as happened with my wife's 2021!) among other things.
Misfires can be physical - valve timing, valve lift, lash adjuster, rocker, cam and more.

These operate on the bleeding edge. As Dave has pointed out, actually at stoic - hard to achieve. It's hard to stand with the centers of your feet at the very edge of the face of the cliff for the best view and not fall over the edge now and then. (ask these idiots trying to make fame for themselves trying to get the best selfie. Oh, they made the news, alright.)

 

[Hootbro]

These are very different misfire issues. Very specific circumstances, not random, but certain events have to happen in the right order at the right time.
This isn't a cold misfire, happens only when hot and after being shut down for a certain length of time (or for enough time for certain things to take place,. like heat transfer, etc.)
I count this, so far, as a 2022 MY specific issue, not to be lumped in with every other misfire.
We've not seen this type on any 2020 model year, and my recollection indicated it wasn't happening in this way in the 2021 MY, either.

So we can't say "my truck misfired, what's the fix" like everyone seems to love to do.
The misfires for the 2020 models were extremely different as far as root causes.
We've seen one sort of misfire in past model years resolved by PCM flash - I'd not be surprised to see something similar happen here due to the circumstances I've experienced personally, and all of my logging.

I am wondering if it is related to the GPEC5 PCM introduction late 2021 model year?

 

[ChrisNLA]

I began watching misfires this morning on JScan for giggles. My drive to work is very short, only 5 miles, after sitting all night, 60* temps this morning.

Cyl 2 - 0
Cyl 4 - 1
Cyl 6 - 1

Cyl 1 - 0
Cyl 3 - 7
Cyl 5 - 2

I will take the longer way home this afternoon, and some longer drives this weekend. My truck only threw the P0300 CEL once, briefly (a week and a half ago). When that happened I had drove for an hour, it sat in the driveway for an hour, then it happened at low RPM, under 20 MPH while leaving.

I am purely speculating - but I feel on these '22s the problem is more closely related to tuning or how something is being read by the PCM then say, a 'hardware' failure (like eating a cam).

 

[ShadowsPapa]

I am wondering if it is related to the GPEC5 PCM introduction late 2021 model year?

That had crossed my mind - I wasn't saying anything related to that because I have yet to see a 2021 with the misfires connected to the same scenario - but just because I have not seen one doesn't mean it hasn't happened to any late 2021 model year.

My dealer talked to the service department at their location and said he wants me to bring it in as soon as it's convenient.
I still want someone like Dave or some other expert to look at my logs and freeze frames, screen captures and so on, though, to see if I'm reading things totally wrong, if I'm not smart enough to get the long and short term trim numbers, so I can add some commentary to the logs I'll take in with the truck.
I captured real-time info on the way back from Florida as my wife was driving and was confused by the very different numbers bank 1 vs bank 2 - but then there are times it's not all that hard to cause me confusion and I'm old school - still, if I found differences in sniff results on a carbureted vehicle, I'd question the carburetor.

 

[ShadowsPapa]

I began watching misfires this morning on JScan for giggles. My drive to work is very short, only 5 miles, after sitting all night, 60* temps this morning.

Cyl 2 - 0
Cyl 4 - 1
Cyl 6 - 1

Cyl 1 - 0
Cyl 3 - 7
Cyl 5 - 2

I will take the longer way home this afternoon, and some longer drives this weekend. My truck only threw the P0300 CEL once, briefly (a week and a half ago). When that happened I had drove for an hour, it sat in the driveway for an hour, then it happened at low RPM, under 20 MPH while leaving.

I am purely speculating - but I feel on these '22s the problem is more closely related to tuning or how something is being read by the PCM then say, a 'hardware' failure (like eating a cam).

The misfire numbers under normal driving - like you've got, aren't scary to me - those look similar to what my 2020 did, and aren't much different from my 2022 when it's working normally.

Numbers like this bug me, though. Maybe a real expert will pop in and say "stop being paranoid and learn how it works - that's normal" but for now, it seems weird.
MINUS long term, MINUS short term on one bank, positive numbers for both for the other.

Sponsored