Trying to gather info to find commonality on "misfires"

[Maximus Gladius]

Update on my random cold start #4 cylinder misfire previously discussed:

https://www.jeepgladiatorforum.com/...monality-on-misfires.46334/page-3#post-764295

Still waiting on my oil analysis from Blackstone that is at least week behind their usual turn around time as of this writing.

Came up on my 30K mile service this weekend and decide to go ahead and do the spark plug change out and while I was in there swapped the #4 fuel injector and Ignition coil to another position. After all that, still have the #4 cylinder showing a small misfire count on cold startup. So unless the oil analysis shows a coolant issue, probably looking at valvetrain or head issue issue.

At this point, since the intermittent P0304 code is always a pending but never posting and no discernable driving issue or engine noise concern, probably going to just live with it as I know the dealership is not going to jump on this with no hard code setting for the P0304 code.

I will say after doing the spark plug swap by the book from Tech Authority info and the quoted 2.0 hours of shop time they give, there is no way in hell a dealership tech will meet that 2.0 hour quote without being absolutely ham fisted in doing the job. 4.0 would be a more realistic time to do it right. Shop Manual info also does not list out disconnecting wiring stand offs and few other odds and ends that are attached to the upper intake manifold. .

Thanks for the update!

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[ShadowsPapa]

Update on my random cold start #4 cylinder misfire previously discussed:

https://www.jeepgladiatorforum.com/...monality-on-misfires.46334/page-3#post-764295

Still waiting on my oil analysis from Blackstone that is at least week behind their usual turn around time as of this writing.

Came up on my 30K mile service this weekend and decide to go ahead and do the spark plug change out and while I was in there swapped the #4 fuel injector and Ignition coil to another position. After all that, still have the #4 cylinder showing a small misfire count on cold startup. So unless the oil analysis shows a coolant issue, probably looking at valvetrain or head issue.

At this point, since the intermittent P0304 code is always a pending but never posting and no discernable driving issue or engine noise concern, probably going to just live with it as I know the dealership is not going to jump on this with no hard code setting for the P0304 code.

I will say after doing the spark plug swap by the book from Tech Authority info and the quoted 2.0 hours of shop time they give, there is no way in hell a dealership tech will meet that 2.0 hour quote without being absolutely ham fisted in doing the job. 4.0 would be a more realistic time to do it right. Shop Manual info also does not list out disconnecting wiring stand offs and few other odds and ends that are attached to the upper intake manifold.

Update:

I also check the removed spark plugs with color and wear matching the other cylinders for the #4. Also bore scoped to look inside the #4 cylinder and seems to show usual and comparable combustion deposits and not clean like a coolant leak would show.

What about a small leak when cold - not leaking once hot.

as I know the dealership is not going to jump on this with no hard code setting for the P0304 code.

Ours did when I showed them the log. Remember, there was no MIL, no code set and they couldn't replicate the issue except to get a single misfire while working with it.

 

[Hootbro]

Finally received my Blackstone Labs report. It actually looks pretty good with very low to almost nothing showing for Potassium and Sodium to indicate any coolant leakage.

Since the spark plug change and swapping the fuel injector and coil around, I have had no ESS disable message or any pending P0304 showing on scan data. #4 cylinder cold start misfire count has been lowered but is still higher than what the other cylinders show. So I am still not discounting a possible valve train or head contributing factor but until this migrates beyond only intermittent pending codes and starts posting permanent codes tripping the CIL, I am not going to be picking this scab. Only regret is I wish I had thought of doing a cylinder compression test when I had it tore apart for the spark plug change out.

Only other troubleshooting action I am going to take is pressure test the coolant system. Waiting on an adapter for the coolant fill tank to come in from Amazon to do that. Given the oil analysis, not expecting it to fail.

 

[Hootbro]

Since my last post, I was still getting the ESS diabled message and the random pending but not posting P0304 #4 cylinder misfire about every 5-7 days. I continued to monitor my misfire count on cold startup and still had double digit misfire counts on #4 cylinder.

This past Friday, I went ahead and did a intake cleaning service with Sea Foam. After the 15-20 minute soak, took the Gladiator down the road for an "Italian Tune-Up" to blow out whatever the Sea Foam loosened up.

I can say for the last 4 days since the Sea Foam treatment, monitoring every cold startup has shown zero misfire on the #4 cylinder. So far, things are looking good and this is the first positive I have had in dealing with this single cylinder misfire issue.

I would also note that when I did the "Italian Tune-up" run, I was monitoring the misfire counters and while I expected some high misfire counts until the Sea Foam gunk had worked its way out, I notice the left bank Cylinders #2, 4, & 6 had misfire counts that were triple the right bank Cylinders #1, 3, & 4. This leads me to believe there is some different atomization of intake air going to the left bank than the right bank. My speculation is that it has to do with the PCV inlet is on the left side of the intake and forcing more of the PCV fuel/oil vapor re-circulation mix to be consume by the left intake bank than the right intake bank.

If it continues to show positive results, I may just be resigned to doing a Sea Foam intake cleaning treatment every 10K miles or so and I would be OK with that.

 

[Maximus Gladius]

Since my last post, I was still getting the ESS diabled message and the random pending but not posting P0304 #4 cylinder misfire about every 5-7 days. I continued to monitor my misfire count on cold startup and still had double digit misfire counts on #4 cylinder.

This past Friday, I went ahead and did a intake cleaning service with Sea Foam. After the 15-20 minute soak, took the Gladiator down the road for an "Italian Tune-Up" to blow out whatever the Sea Foam loosened up.

I can say for the last 4 days since the Sea Foam treatment, monitoring every cold startup has shown zero misfire on the #4 cylinder. So far, things are looking good and this is the first positive I have had in dealing with this single cylinder misfire issue.

I would also note that when I did the "Italian Tune-up" run, I was monitoring the misfire counters and while I expected some high misfire counts until the Sea Foam gunk and worked its way out, I notice the left bank Cylinders #2, 4, & 6 had misfire counts that were triple the right bank Cylinders #1, 3, & 4. This leads me to believe there is some different atomization of intake air going to the left bank than the right bank. My speculation is that it has to do with the PCV inlet is on the left side of the intake and forcing more of the PCV fuel/oil vapor re-circulation mix to be consume by the left intake bank than the right intake bank.

If it continues to show positive results, I may just be resigned to doing a Sea Foam intake cleaning treatment every 10K miles or so and I would be OK with that.

Please explain the “Italian tune up”! Do you have someone keeping the rpm’s up while spraying the sea foam in? Then after disposing the cam did you drive it like you stole it?

 

[ShadowsPapa]

Please explain the “Italian tune up”! Do you have someone keeping the rpm’s up while spraying the sea foam in? Then after disposing the cam did you drive it like you stole it?

Taking it out and driving it like a 16 year old trying to impress his girl.

 

[Hootbro]

Please explain the “Italian tune up”! Do you have someone keeping the rpm’s up while spraying the sea foam in? Then after disposing the cam did you drive it like you stole it?

You got the basic gist of it.

Right behind the throttle body on the 3.6L intake is a small right angle vacuum hose. At engine idle, remove the hose and with a piece of small hose attached to the intake nipple, just very slowly sip small amount of the Sea Foam being careful to not stall it. Turn off engine, then let soak 15-20 minutes and then take it for a rip down the road. You will fog the neighborhood for a few minutes though.

 

[ShadowsPapa]

Since my last post, I was still getting the ESS diabled message and the random pending but not posting P0304 #4 cylinder misfire about every 5-7 days. I continued to monitor my misfire count on cold startup and still had double digit misfire counts on #4 cylinder.

This past Friday, I went ahead and did a intake cleaning service with Sea Foam. After the 15-20 minute soak, took the Gladiator down the road for an "Italian Tune-Up" to blow out whatever the Sea Foam loosened up.

I can say for the last 4 days since the Sea Foam treatment, monitoring every cold startup has shown zero misfire on the #4 cylinder. So far, things are looking good and this is the first positive I have had in dealing with this single cylinder misfire issue.

I would also note that when I did the "Italian Tune-up" run, I was monitoring the misfire counters and while I expected some high misfire counts until the Sea Foam gunk and worked its way out, I notice the left bank Cylinders #2, 4, & 6 had misfire counts that were triple the right bank Cylinders #1, 3, & 4. This leads me to believe there is some different atomization of intake air going to the left bank than the right bank. My speculation is that it has to do with the PCV inlet is on the left side of the intake and forcing more of the PCV fuel/oil vapor re-circulation mix to be consume by the left intake bank than the right intake bank.

If it continues to show positive results, I may just be resigned to doing a Sea Foam intake cleaning treatment every 10K miles or so and I would be OK with that.

I know EGR won't count on a cold start - but - gotta ask - is it distributed evenly? (not going to have impact on the cold misfire scenario, but just curious (it won't unless there's an EGR issue of course)

I've been finding references to these running better after a good romp on race day - and even my own seems to like being taken out and flogged now and then. Not abusing, but not driving it like my wife is with me, either.

 

[ShadowsPapa]

You got the basic gist of it.

Right behind the throttle body on the 3.6L intake is a small right angle vacuum hose. At engine idle, remove the hose and just very slowly sip small amount of the Sea Foam being careful to not stall it. Turn off engine, then let soak 15-20 minutes and then take it for a rip down the road. You will fog the neighborhood for a few minutes though.

That's how we used to handle cars where the owner brought them in saying they had a bit of a ping, or they just didn't respond like they used to or the idle was a bit rough. We'd use Wynn's products back them. Hold the throttle to prevent the engine from dying, sipping the Wynn's product down its throat, then killing it with the last bit, let it sit, then take it out on an abandoned portion of highway 141 with no traffic and drive it like the cops were chasing you.

When the owner was old and had little money, we'd use a Coke bottle of water - "steam clean" - it blew out any carbon or oil accumulations in the intake and cylinders. It was totally amazing how either, the Wynn's product or water, made things smooth out and if the ping was due to carbon - no more ping!

 

[Hootbro]

I know EGR won't count on a cold start - but - gotta ask - is it distributed evenly? (not going to have impact on the cold misfire scenario, but just curious (it won't unless there's an EGR issue of course)

I've been finding references to these running better after a good romp on race day - and even my own seems to like being taken out and flogged now and then. Not abusing, but not driving it like my wife is with me, either.

As to the EGR which by the way is also attached to the left side of the intake plenum, I have to say I really do not know for certain. My speculation is that while air pressure is air pressure and should be equalized across all cylinders of the intake, it will be the heavier than air particles like soot from the EGR and or fuel/oil vapors from the PCV system that will settle more across the left bank path than the right bank.

Up until about 5 years or so, I use to Sea Foam intakes quite regularly on my vehicles. Since then, I had bought into the mantra that using Tier 1 gas and the more modern engine emissions and fuel delivery systems made than somewhat moot. I will probably change my thinking on that.

 

[Maximus Gladius]

I’m kinda using water injection into my cylinders via coolant leak so I wonder if having the leak is actually a good thing which explains why it’s running so good!

Just an update on my internal leak, at 16,600k klms when I took my truck in for the misfire, I had topped up the coolant (engine cold) to the MAX full line. I’m now at 19300k klms and the level has dropped, as of this morning (cold) to halfway between MAX and MIN lines.

 

[Jeepin' John]

So using jscan (or similar), how many misfires are "normal" over say, a 30 min drive? I'm getting 1 to 3 per cylinder, pretty evenly spread out, not one cylinder more than another. Is that ok?

 

[Hootbro]

So using jscan (or similar), how many misfires are "normal" over say, a 30 min drive? I'm getting 1 to 3 per cylinder, pretty evenly spread out, not one cylinder more than another. Is that ok?

That is about normal. Another thing to consider is that the PCM methodology in how it counts a misfire is not always a true no spark or incomplete combustion and is sometimes just a "guess" that a misfire occurred. So those single digits counts over long periods of run time are inconsequential.

 

[Jeepin' John]

That is about normal. Another thing to consider is that the PCM methodology in how it counts a misfire is not always a true no spark or incomplete combustion and is sometimes just a "guess" that a misfire occurred. So those single digits counts over long periods of run time are inconsequential.

Thanks and i hope you've got yours sorted out!

 

[Maximus Gladius]

Finally received my Blackstone Labs report. It actually looks pretty good with very low to almost nothing showing for Potassium and Sodium to indicate any coolant leakage.

Since the spark plug change and swapping the fuel injector and coil around, I have had no ESS disable message or any pending P0304 showing on scan data. #4 cylinder cold start misfire count has been lowered but is still higher than what the other cylinders show. So I am still not discounting a possible valve train or head contributing factor but until this migrates beyond only intermittent pending codes and starts posting permanent codes tripping the CIL, I am not going to be picking this scab. Only regret is I wish I had thought of doing a cylinder compression test when I had it tore apart for the spark plug change out.

Only other troubleshooting action I am going to take is pressure test the coolant system. Waiting on an adapter for the coolant fill tank to come in from Amazon to do that. Given the oil analysis, not expecting it to fail.

What is your current miles on the truck?

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