3.6L Pentastar Problems?

[Hootbro]

Might see more misfire issues now with the gladiator. Dealing with two on mine last month. There’s been a few noted here if you look it up. Looks like the fix so far that’s done anything positive is to replace a damaged cam shaft and rockers and other bits. Mine just so happens to also have an internal coolant leak too. Related to the misfire?? I’ll say it is until tech support wants to acknowledge and prove my theory wrong.

Just wondering, what is the evidence of a coolant leak in your case?

White Smoke on startup? Evidence in the oil?

The reason I ask is I have a random pending but never posting P0304 Cylinder #4 misfire code I am trying to figure out. I have an oil sample out to Blackstone Labs I am waiting on and have no white smoke on startup. Since I have bought mine in May 2019, I have maybe added 8oz of coolant to bring up the level in the reservoir tank and that really is not much over time in my opinion.

Sponsored

 

[Maximus Gladius]

Just wondering, what is the evidence of a coolant leak in your case?

White Smoke on startup? Evidence in the oil?

The reason I ask is I have a random pending but never posting P0304 Cylinder #4 misfire code I am trying to figure out. I have an oil sample out to Blackstone Labs I am waiting on and have no white smoke on startup. Since I have bought mine in May 2019, I have maybe added 8oz of coolant to bring up the level in the reservoir tank and that really is not much over time in my opinion.

The evidence in my case is in the oil sample analysis reports.
-My first report was done at my first oil change @ 1000 kms. Analysis stated "Tests indicate the need to change oil and filter" Glycol reading "Trace" (I thought it was contaminated oil at the factory)
-Second oil analysis was done at my second oil change @ 10,000 kms. Report says, "ALERT! Tests indicate the need to change oil and filter. Check for a coolant leak. Please monitor Glycol contamination". Glycol - "Trace" (I consumed 2 cups of coolant in 10,000 kms)

I immediately went to the lab tech and talked with him. He said at this stage of the game there could still be an amount of the first contaminated oil still floating around and/or the engine has just burped out an air lock and I've had to top off the coolant. Wait for the 3rd sample but bring it in @ 16,000 kms.

The day I brought in the early oil sample, I got a PO302 engine warning. (Cylinder #2 misfire) Took truck to dealership to get the OBD2 engine code read. It was late Thursday. I couldn't get the truck in till Monday. Tech found the misfire to be the injector and replaced it and I got the truck back Tuesday morning. Tuesday afternoon, 2nd misfire happened again AND i was emailed my oil lab results.

Result stated "ALERT!, Tests indicate the need to Change oil and filter. Check for a coolant leak. Please monitor Glycol contamination."

I took the truck back in with the 3 lab results and gave them a copy and said, I believe my coolant leak is directly related to the cylinder #2 misfire as that is where my consumed coolant is going when I stomp on the throttle, misfire takes place and the truck vibrates violently.

The service advisor didnt know what to do with the report as they've never seen this before and asked why am I doing this?? I said, for one, it proves I change my oil on time and second, an oil analysis is hard data on the health of the engine. There's no guess work here. I am consuming coolant AND misfiring.

Two days later service advisor contacts me to say the tech read my analysis and stated " coolant in the oil is NORMAL" and disregarded the report. I asked for that in writing to which I'm still waiting for.

I reported the comment to FCA and said the dealership tech, service advisor and perhaps others have knowingly withheld this critical information ON PURPOSE to obtain a procedurally incorrect repair path. FCA instructed me to speak with the service manager and I spelled it out for him too. He contacted me the next week to say they informed FCA engineers of my leak and the comment back from the top is "coolant in the oil did not damage the camshaft". PERIOD.

They are proceeding with the cam repair as soon as it arrives next week.

I've gone to another dealership and spoke with that service manager who is less than impressed with whats happened with my case. He wants my truck when the next misfire takes place. He said it is not unreasonable to get a new engine if the internal leak persists. He said they've had 9 camshaft misfire repairs this year and "a close by dealership has had significantly more"

 

[Hootbro]

The evidence in my case is in the oil sample analysis reports.
-My first report was done at my first oil change @ 1000 kms. Analysis stated "Tests indicate the need to change oil and filter" Glycol reading "Trace" (I thought it was contaminated oil at the factory)
-Second oil analysis was done at my second oil change @ 10,000 kms. Report says, "ALERT! Tests indicate the need to change oil and filter. Check for a coolant leak. Please monitor Glycol contamination". Glycol - "Trace" (I consumed 2 cups of coolant in 10,000 kms)

I immediately went to the lab tech and talked with him. He said at this stage of the game there could still be an amount of the first contaminated oil still floating around and/or the engine has just burped out an air lock and I've had to top off the coolant. Wait for the 3rd sample but bring it in @ 16,000 kms.

The day I brought in the early oil sample, I got a PO302 engine warning. (Cylinder #2 misfire) Took truck to dealership to get the OBD2 engine code read. It was late Thursday. I couldn't get the truck in till Monday. Tech found the misfire to be the injector and replaced it and I got the truck back Tuesday morning. Tuesday afternoon, 2nd misfire happened again AND i was emailed my oil lab results.

Result stated "ALERT!, Tests indicate the need to Change oil and filter. Check for a coolant leak. Please monitor Glycol contamination."

I took the truck back in with the 3 lab results and gave them a copy and said, I believe my coolant leak is directly related to the cylinder #2 misfire as that is where my consumed coolant is going when I stomp on the throttle, misfire takes place and the truck vibrates violently.

The service advisor didnt know what to do with the report as they've never seen this before and asked why am I doing this?? I said, for one, it proves I change my oil on time and second, an oil analysis is hard data on the health of the engine. There's no guess work here. I am consuming coolant AND misfiring.

Two days later service advisor contacts me to say the tech read my analysis and stated " coolant in the oil is NORMAL" and disregarded the report. I asked for that in writing to which I'm still waiting for.

I reported the comment to FCA and said the dealership tech, service advisor and perhaps others have knowingly withheld this critical information ON PURPOSE to obtain a procedurally incorrect repair path. FCA instructed me to speak with the service manager and I spelled it out for him too. He contacted me the next week to say they informed FCA engineers of my leak and the comment back from the top is "coolant in the oil did not damage the camshaft". PERIOD.

They are proceeding with the cam repair as soon as it arrives next week.

I've gone to another dealership and spoke with that service manager who is less than impressed with whats happened with my case. He wants my truck when the next misfire takes place. He said it is not unreasonable to get a new engine if the internal leak persists. He said they've had 9 camshaft misfire repairs this year and "a close by dealership has had significantly more"

Thanks. Sounds like a shit show with the dealership.

I have heard from others that dealership service departments just do not know how to handle third party oil analysis data when presented as it throws them out of their mode of the usual troubleshooting path and requires critical thinking.

Your misfire problems are way advance beyond my issue with mine. Hopefully you get attention to your issue.

 

[Maximus Gladius]

Thanks. Sounds like a shit show with the dealership.

I have heard from others that dealership service departments just do not know how to handle third party oil analysis data when presented as it throws them out of their mode of the usual troubleshooting path and requires critical thinking.

Your misfire problems are way advance beyond my issue with mine. Hopefully you get attention to your issue.

Just as you said, “it requires critical thinking”.
I told my service adviser the same thing and said it was clearly needed. The second dealership service manager said this one requires critical thinking too. They just don’t get paid the time to do that.

Please share your oil analysis report. I’m very curious.

 

[trailless]

I had a hell of time with my 2014 JK that had the 3.6L pentastar...

30k miles dealer replaced the cam phaser, cam shaft and some other related stuff
37k miles the thermostat went out
40k miles the rear main seal went out
43k miles the oil filter housing cracked
50k miles crankshaft position sensor went out. The jeep would randomly die while driving, sometimes at 30 mph and sometimes at 80 mph. Engine completely dies, no power steering or brakes. It wouldn't restart until it sat for around 15 minutes. Dealer couldn't find the issue but I found the answer on the forums. This was the most frustrating part and also a giant safety hazard. Imagine driving 85mph in the left lane and then the jeep just dying. Then I have to merge 4+ lanes to the right shoulder, in traffic, with no power...
100k miles had to replace the timing chains... One of them was stretched out somehow.

I did 5k mile oil changes with full synthetic and replaced the oil filter every time with a mopar filter.

 

[Renegade]

The evidence in my case is in the oil sample analysis reports.
-My first report was done at my first oil change @ 1000 kms. Analysis stated "Tests indicate the need to change oil and filter" Glycol reading "Trace" (I thought it was contaminated oil at the factory)
-Second oil analysis was done at my second oil change @ 10,000 kms. Report says, "ALERT! Tests indicate the need to change oil and filter. Check for a coolant leak. Please monitor Glycol contamination". Glycol - "Trace" (I consumed 2 cups of coolant in 10,000 kms)

I immediately went to the lab tech and talked with him. He said at this stage of the game there could still be an amount of the first contaminated oil still floating around and/or the engine has just burped out an air lock and I've had to top off the coolant. Wait for the 3rd sample but bring it in @ 16,000 kms.

The day I brought in the early oil sample, I got a PO302 engine warning. (Cylinder #2 misfire) Took truck to dealership to get the OBD2 engine code read. It was late Thursday. I couldn't get the truck in till Monday. Tech found the misfire to be the injector and replaced it and I got the truck back Tuesday morning. Tuesday afternoon, 2nd misfire happened again AND i was emailed my oil lab results.

Result stated "ALERT!, Tests indicate the need to Change oil and filter. Check for a coolant leak. Please monitor Glycol contamination."

I took the truck back in with the 3 lab results and gave them a copy and said, I believe my coolant leak is directly related to the cylinder #2 misfire as that is where my consumed coolant is going when I stomp on the throttle, misfire takes place and the truck vibrates violently.

The service advisor didnt know what to do with the report as they've never seen this before and asked why am I doing this?? I said, for one, it proves I change my oil on time and second, an oil analysis is hard data on the health of the engine. There's no guess work here. I am consuming coolant AND misfiring.

Two days later service advisor contacts me to say the tech read my analysis and stated " coolant in the oil is NORMAL" and disregarded the report. I asked for that in writing to which I'm still waiting for.

I reported the comment to FCA and said the dealership tech, service advisor and perhaps others have knowingly withheld this critical information ON PURPOSE to obtain a procedurally incorrect repair path. FCA instructed me to speak with the service manager and I spelled it out for him too. He contacted me the next week to say they informed FCA engineers of my leak and the comment back from the top is "coolant in the oil did not damage the camshaft". PERIOD.

They are proceeding with the cam repair as soon as it arrives next week.

I've gone to another dealership and spoke with that service manager who is less than impressed with whats happened with my case. He wants my truck when the next misfire takes place. He said it is not unreasonable to get a new engine if the internal leak persists. He said they've had 9 camshaft misfire repairs this year and "a close by dealership has had significantly more"

Head gasket leak?

 

[Maximus Gladius]

Head gasket leak?

Highly possible. A few things troubling here is my truck is FIRSTLY, out in the lot with the top of the engine pulled off and covered with a couple rags. For a whole month, just a rag covers the exposed engine, well, and the hood. Truck looks like shit while a BIG sign on the lot says "new inventory is safely stored indoors". The lot is empty, and indoors isn't much to speak of.
SECOND, every time I spoke with the service advisor and with FCA I would constantly be bringing the internal leak front and centre. To me it was obvious there's a problem with the head gasket so I felt some misguided relief assuming when they decided to change out the cam and other bits due to the "valve is not seating..." the head would be removed to reseat the gummed up valve(s) in cylinder #2 and thereby would replace the head gasket and my "leak" would be fixed. NOPE. They are not removing the head to reseat the valve(s). Not grinding the surfaces because they aren't equipped for that

They are not allowed to go past lifting off the valve cover and cams. To go further would require my permission (my commitment to pay $$$) for them to go digging looking for a coolant leak. I said, why would I spend $$$ for them to go through my engine which may result in them not finding anything especially if the glycol readings, currently, is only "trace" amounts for now.

Analysis numbers do show the SODIUM is climbing. Eventually, "trace" amounts will be measurable and then down the road further, perhaps a catastrophe awaits. Coolant in the oil will only damage bearings.

I've called a couple rebuild shops that would charge about $6000 cad to rebuild - bore out cylinders, upgrade rings and bearings etc and have a better built engine with more professional hands on building.

I said, my fix is to give me a new engine. My analysis reports show this had a leak from day one. Take this engine and replace it. They can dig around the old engine on their time and dime, not me. These misfires that are showing to be popular now...I've got hard data which may suggest there's a casting problem or a gasket problem or torque problems and my oil analysis says I'm consuming coolant that is not "normal". My engine is not burping air locks in the cooling system at 16,000 kms.

The latest service manager I sat down with that admired my efforts to get my reports done said in his 20 years wrenching he'd only seen a hand full of people who would get oil analysis work done on their rigs. He had been waiting years for someone like me to come in with a report and a theory linking misfires to coolant leaks. We dont do enough critical thinking here, we dont' get paid for that.

 

[Hootbro]

Highly possible. A few things troubling here is my truck is FIRSTLY, out in the lot with the top of the engine pulled off and covered with a couple rags. For a whole month, just a rag covers the exposed engine, well, and the hood. Truck looks like shit while a BIG sign on the lot says "new inventory is safely stored indoors". The lot is empty, and indoors isn't much to speak of.
SECOND, every time I spoke with the service advisor and with FCA I would constantly be bringing the internal leak front and centre. To me it was obvious there's a problem with the head gasket so I felt some misguided relief assuming when they decided to change out the cam and other bits due to the "valve is not seating..." the head would be removed to reseat the gummed up valve(s) in cylinder #2 and thereby would replace the head gasket and my "leak" would be fixed. NOPE. They are not removing the head to reseat the valve(s). Not grinding the surfaces because they aren't equipped for that

They are not allowed to go past lifting off the valve cover and cams. To go further would require my permission (my commitment to pay $$$) for them to go digging looking for a coolant leak. I said, why would I spend $$$ for them to go through my engine which may result in them not finding anything especially if the glycol readings, currently, is only "trace" amounts for now.

Analysis numbers do show the SODIUM is climbing. Eventually, "trace" amounts will be measurable and then down the road further, perhaps a catastrophe awaits. Coolant in the oil will only damage bearings.

I've called a couple rebuild shops that would charge about $6000 cad to rebuild - bore out cylinders, upgrade rings and bearings etc and have a better built engine with more professional hands on building.

I said, my fix is to give me a new engine. My analysis reports show this had a leak from day one. Take this engine and replace it. They can dig around the old engine on their time and dime, not me. These misfires that are showing to be popular now...I've got hard data which may suggest there's a casting problem or a gasket problem or torque problems and my oil analysis says I'm consuming coolant that is not "normal". My engine is not burping air locks in the cooling system at 16,000 kms.

The latest service manager I sat down with that admired my efforts to get my reports done said in his 20 years wrenching he'd only seen a hand full of people who would get oil analysis work done on their rigs. He had been waiting years for someone like me to come in with a report and a theory linking misfires to coolant leaks. We dont do enough critical thinking here, we dont' get paid for that.

Sounds like you need to "help" your engine have more than "trace amount" of coolant in the oil to get it over the hump and have them warranty replace the engine.

I sure as hell would not be playing this death by a thousand paper cuts troubleshooting process the dealership and corporate is insisting on. They are going to nurse this until you are out of warranty.

 

[ShadowsPapa]

Just wondering, what is the evidence of a coolant leak in your case?

White Smoke on startup? Evidence in the oil?

The reason I ask is I have a random pending but never posting P0304 Cylinder #4 misfire code I am trying to figure out. I have an oil sample out to Blackstone Labs I am waiting on and have no white smoke on startup. Since I have bought mine in May 2019, I have maybe added 8oz of coolant to bring up the level in the reservoir tank and that really is not much over time in my opinion.

I've read the oil analysis, that combined with the fact he's had to add any coolant at all.
These should go months if not a year or two without needing to add coolant. Coolant is not going to just disappear.
He's also got sodium and other elements that are typically the result of the breakdown of glycol in the oil. Glycol in oil is extremely hard to track because it's broken down at temperatures of over 200 degrees for prolonged periods. Oil runs that and more - for as long as you drive it. So you won't find glycol in normal USED engine oil. You will find the byproducts of glycol if glycol existed in the oil.
The fact he has no external coolant leaks but has had to add multiple times is very telling in my experience.
You don't have to see white "smoke" out the back.......... if you do then you have very serious issues. There's a lot of places and ways coolant can get into oil without being dropped right on top of the piston to burn. A head gasket leak can send coolant into the combustion chamber, or directly outside to the floor, or into the oil and not being touched by the flame of combustion, or a mix of all of the above.

The tough part of misfires is that if 100 people experience "3.6 misfires" there may be 3 or 4 different causes with one of those causing 90 of those misfires and the other 10 being based on other issues.
That's why I started a thread trying to find anyone else who has had to add coolant to their JT.
Unless you have a leak - adding coolant to a modern vehicle is a rare thing. Mine has never had coolant added and is exactly where it belongs on the marks. Heck, I can go a year and never add coolant to my 82. So why would people have to be adding coolant to a JT not even 2 years old?

 

[Hootbro]

I do not buy into the notion coolant should never evaporate or be lost in a otherwise normal operating system that is still over pressure vented. The question is how much is too much over time? It is not a perfectly sealed system like air conditioning is but pretty close to it.

In my case, I am not sweating 8oz to top off in almost 20 months of use and quite frankly, I never checked where it was at from the factory so it could have been low already. That is why I am waiting on my oil analysis return to see what is what and go from that data point.

My issue and coolant loss is not anywhere near what @Maximus Gladius is experiencing. Until my oil analysis returns, I cannot positively rule out coolant though for my minor misfire before I can move on to spark, fuel and ignition troubleshooting.

 

[ShadowsPapa]

I do not buy into the notion coolant should never evaporate or be lost in a otherwise normal operating system that is still over pressure vented. The question is how much is too much over time? It is not a perfectly sealed system like air conditioning is but pretty close to it.

In my case, I am not sweating 8oz to top off in almost 20 months of use and quite frankly, I never checked where it was at from the factory so it could have been low already. That is why I am waiting on my oil analysis return to see what is what and go from that data point.

My issue and coolant loss is not anywhere near what @Maximus Gladius is experiencing. Until my oil analysis returns, I cannot positively rule out coolant though for my minor misfire before I can move on to spark, fuel and ignition troubleshooting.

November 2019 build date - I've not added coolant, and I keep track with the weird stuff people are talking about. I check all fluids after all that, and having found my PS tank beyond low after the last gear change. So I keep track of things pretty close on it.

3 years on my 82 (granted, with a 4.0 and coolant recovery system) - no coolant added between when it was changed last time and when I changed it this last spring.
My 2011 Silverado - it was changed once, but otherwise - and I seem to recall over those 8 years I did add some at one time, about when I checked things over after replacing the battery.
My wife's Grand Cherokees have not required the addition of coolant other than small amounts once or twice over the years.
Evaporation is extremely low because of the location of the reservoir and venting - the coolant there isn't hot and steaming.
When steam is vented, you lose moisture - when you vent out pressurized air from that remote tank, there's almost nothing in it for moisture content. You could go easily a couple of years and not lose enough to need to add.
I checked everything over on mine in May before Colorado trip, have put a lot of miles on it since then - coolant is still right where it was back in May.
You are not venting steam or venting from a tank that's 200+ degrees with hot coolant in it, it's pressure from a remote tank that's generally not letting much "coolant" out with the vented air pressure.
They can allow you to go years without changing coolant in part because it doesn't mix with contaminates in the air. Pretty close to a sealed system.
I'd say if you have to add more than 3 or 4 ounces of coolant in a 10,000 mile period, check things over. (If you tow in the mountains, YMMV, as they say)

 

[Hootbro]

November 2019 build date - I've not added coolant, and I keep track with the weird stuff people are talking about. I check all fluids after all that, and having found my PS tank beyond low after the last gear change. So I keep track of things pretty close on it.

3 years on my 82 (granted, with a 4.0 and coolant recovery system) - no coolant added between when it was changed last time and when I changed it this last spring.
My 2011 Silverado - it was changed once, but otherwise - and I seem to recall over those 8 years I did add some at one time, about when I checked things over after replacing the battery.
My wife's Grand Cherokees have not required the addition of coolant other than small amounts once or twice over the years.
Evaporation is extremely low because of the location of the reservoir and venting - the coolant there isn't hot and steaming.
When steam is vented, you lose moisture - when you vent out pressurized air from that remote tank, there's almost nothing in it for moisture content. You could go easily a couple of years and not lose enough to need to add.
I checked everything over on mine in May before Colorado trip, have put a lot of miles on it since then - coolant is still right where it was back in May.
You are not venting steam or venting from a tank that's 200+ degrees with hot coolant in it, it's pressure from a remote tank that's generally not letting much "coolant" out with the vented air pressure.
They can allow you to go years without changing coolant in part because it doesn't mix with contaminates in the air. Pretty close to a sealed system.
I'd say if you have to add more than 3 or 4 ounces of coolant in a 10,000 mile period, check things over. (If you tow in the mountains, YMMV, as they say)

Ok

 

[Maximus Gladius]

I do not buy into the notion coolant should never evaporate or be lost in a otherwise normal operating system that is still over pressure vented. The question is how much is too much over time? It is not a perfectly sealed system like air conditioning is but pretty close to it.

In my case, I am not sweating 8oz to top off in almost 20 months of use and quite frankly, I never checked where it was at from the factory so it could have been low already. That is why I am waiting on my oil analysis return to see what is what and go from that data point.

My issue and coolant loss is not anywhere near what @Maximus Gladius is experiencing. Until my oil analysis returns, I cannot positively rule out coolant though for my minor misfire before I can move on to spark, fuel and ignition troubleshooting.

Hootbro, I’m curious how you came to make the decision to do an oil analysis. Not many drivers do this. The comments made at the dealership my truck is sitting at by both long employed service advisor and shop manager is they’ve never seen anyone do this. The service manager I’m sure couldn’t understand the data and just set it aside when I was discussing it. The second dealership service manager I went and interviewed him for his mechanical knowledge did know about these private reports and even engaged conversation about the data he was reading said it’s so rare to see people do this.

There’s a forum here consisting of 94 pages of misfire complaints, 94 pages!! I contacted the first 20 or so complaints in the first 10 pages. Out of those 20, 3 members replied to my question about coolant leaks and oil analysis and none of them looked at both.
What made you go there?

 

[ShadowsPapa]

Hootbro, I’m curious how you came to make the decision to do an oil analysis. Not many drivers do this. The comments made at the dealership my truck is sitting at by both long employed service advisor and shop manager is they’ve never seen anyone do this. The service manager I’m sure couldn’t understand the data and just set it aside when I was discussing it. The second dealership service manager I went and interviewed him for his mechanical knowledge did know about these private reports and even engaged conversation about the data he was reading said it’s so rare to see people do this.

There’s a forum here consisting of 94 pages of misfire complaints, 94 pages!! I contacted the first 20 or so complaints in the first 10 pages. Out of those 20, 3 members replied to my question about coolant leaks and oil analysis and none of them looked at both.
What made you go there?

Good question.
It's actually unusual for most people unless they have been involved in racing, high-performance engines or events or very high dollar vehicles.
I've built quite a few engines over the years - for myself, for others, I still have one of them 34,000 miles later, another one is owned by a Texan who drives and shows the car every chance he gets, and I've never sent oil samples off (because there's never been anything unusual, I guess!)

 

[Hootbro]

Hootbro, I’m curious how you came to make the decision to do an oil analysis. Not many drivers do this. The comments made at the dealership my truck is sitting at by both long employed service advisor and shop manager is they’ve never seen anyone do this. The service manager I’m sure couldn’t understand the data and just set it aside when I was discussing it. The second dealership service manager I went and interviewed him for his mechanical knowledge did know about these private reports and even engaged conversation about the data he was reading said it’s so rare to see people do this.

There’s a forum here consisting of 94 pages of misfire complaints, 94 pages!! I contacted the first 20 or so complaints in the first 10 pages. Out of those 20, 3 members replied to my question about coolant leaks and oil analysis and none of them looked at both.
What made you go there?

Have been working in aviation for close to 35 years and oil/fluid analysis is an everyday thing that transposed into my personal vehicle maintenance habits. I try to do one every other oil change to see trends.

This time with my Gladiator, I have had an intermittent once in a blue moon “Start/Stop System Disabled” indication and icon show up on the instrument cluster. Discounted it as a low ESS battery issue and never deep dived it for the longest time because it would go away on next restart. Never had a CIL indication either and never really noticed any performance issues or misfire when driving.

About 2-3 months ago, this “Start/Stop System Disabled” indication would become a now once a week affair. Using JScan as a rudimentary scan tool, I would do an initial scan and there was a pending but never posting P0304 #4 cylinder misfire code. I would then do a PID scan of all 6 cylinders and the #4 cylinder would have a misfire count of 25-65 misfires with the other cylinders either zero or single digits.

The #4 cylinder misfires would only happen on a cold like sitting for 8 hours or more start and would almost never count any higher for my 45 minute commute. For a few week, I would hook up JScan and monitor my misfire count on a cold start and found the #4 cylinder always has a double digit misfire count compared to the other cylinders regardless. “Start/Stop System Disabled” indication only seems to come on when the misfire count gets about 40 count with anything less not setting it.

I know not getting a proper check engine light (CIL) with the P0304 code posting and only a intermittent pending that clears after a couple of restarts, dealing with the dealership service was going to be a donkey show like you are going through. That leads me down the path of usual suspects and getting coolant concerns figured out and hopefully out of the way. If my oil analysis shows nothing to be concerned in regards to coolant, I am coming up on the 30K mile mark here soon and have already bought new spark plugs, intake gaskets and fuel injector o-rings and plan to replace the spark plugs and move both #4 cylinder fuel injector and ignition coil to two different cylinder and see what if anything travels. If nothing travels and seems fixed, call it with the spark plugs. If the moved ignition coil or fuel injector had a misfire on the traveled two cylinder, then call either item to be replaced. If after all that, my issue remains on #4 cylinder, then I am looking at head or valvetrain issues and that will be a dealer visit for warranty and playing that donkey show with them.

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