One correction - the 2013 Pilot is J35Z4. This was never used in any Odyssey. So the coil might or might not be compatible. I seriously doubt the coil was bad. Cylinder 1 misfire around 100k miles is VERY normal for these VCM engines.

Valve lash is not the number one reason for oil consumption. VCM is.

With the Honda warranty - the misfire code was a requirement to qualify for the piston ring replacement. If your Honda dealer can do the work, that would be a great way to get a free timing belt replacement (cost of belt) since they have to remove it to do the re-ring.

Personally, I'd either go the warranty work route if you can get a Honda dealer to perform the work for free.... or:

1. Disable VCM. I like the VCMTuner2 myself. VCM is the cause for this issue.
2. Change the PCV.
3. Change all spark plugs with new NGK Laser Iridium (100k rated) sourced from Rock Auto or an auto parts store (not eBay nor Amazon).
4. Change the oil with Valvoline Restore and Protect 0W20 (or whatever your factory recommended oil viscosity is)
5. Use only Top Tier fuel, and add a Gumout Regane Complete Fuel System Cleaner to each tank for the next 5 tanks.
6. Drive it hard.... when getting on a freeway, open it up more than you usually do. Get the RPM's up with some full throttle applications when you can do so safely.

I would not bother with valve adjustment, personally, until later.

If the timing belt has not been replaced, it is badly overdue, based on age (debatable) and certainly miles (should be changed every 105k miles.) Sounds like the previous owner got the quote for a timing belt, spark plugs, and valve adjustment.... and just dumped the vehicle instead.

 

This is 1000% a VCM problem. Nothing new here. Disable VCM, replace plugs, and move on. No rings needed.

The Odyssey is not exactly the same engine, but the J35Z8 is practically the same as the J35Z4. Either way, the original coil is likely fine.

The VCM mega thread - what is VCM, does my vehicle have...

This thread explains all the key details regarding VCM. Rather than re-explaining everything about VCM to every new forum member, they can simply be directed here. Self-service FTW! While there will be plenty of discussion in this thread, this first post contains the key information, so reading...

www.piloteers.org

 

Fouled plugs in the VCM cylinders is a known issue. Did you check the other plugs in the bank or #4? Those are all subject to VCM shutdown and multiple fouled plugs would point to a probable VCM residue, oil use, and fouling problem. Did you check the coil by switching with another? It would be unusual to have a bad coil at only 112K miles. Were the spark plugs replaced post 100K miles?

Read the first post in the VCM Megathread. Chances are it's the VCM side effects that are the biggest cause. Disable the VCM, put in new plugs if they weren't done post 100K miles, change the PVC valve, do an oil change with full synthetic oil, fill the tank with a Tier One 87 Octane, and do a couple of Italian tuneups after that. If things don't improve (they probably will) move on to further diagnosis.

Re valve adjustment, it is supposed to be checked post 100K. Doing one is not a bad idea but I don't think it is the reason for your excessive oil consumption and fouled spark plug(s).

 

So the coil pack off the Ody works, has some slight visual difference but mounts the same way. And yes, I swapped it with the #4 and the idle check followed it, no change when unplugged, changes when a good coil in the #1 is unplugged. That problem solved.

I just didn't know (not fond of electrical) if a fouled plug could cause the coil to fail. I did not change/inspect the other plugs, as 1)All codes pointed to cyl #1, 2)was pressed for time, and 3)bad financial timing. I did pull one plug for comparison.

.

As for warranty, at 11+ years and >100k miles, I don't see Honda doing anything for free. They also mentioned they won't deal with my aftermarket warranty company (it was a "freebie" from the mom and pop dealership I got the car from). I could do the muzzle and cleanings, but if it turns out to need an actual service I'll be out of warranty and footing it all myself. As a three time Ody owner, I've dealt with the VCM and oil, but never saw it go this fast. So disappointed, I really like this vehicle and want it to last. All my Ody's I bought used at around 100k each, the last one just went at 319k, and only because I stopped putting money/time in to keep it running.

 

but if it turns out to need an actual service

It won't. What is there to service? The rings themselves are fine and were never a solution to the problem.

 

oil treatment? I think you meant to say using a high quality fully synthetic oil without any other additives mixed in.
only additives I would recommend would be certain "flush" solutions to add to the engine right before draining old oil. these are typically dumped into a hot engine and then let idle for 10 to 15 minutes then drain out.
could also try the new restore & protect from valvoline

 

For completeness here's a video I found

 

For completeness here's a video I found

At 45:52 he literally explains how "Eco Mode" (VCM) causes the issue.
The plus and rings are the symptom, not the cause.
Good video, BTW. A fun watch for an amateur wrencher like me A little scary how he goes at the piston with a screwdriver though
Cheers

 

Not sure how much would need to be added and how to a piston soak with Berryman's B12 where you add let sit, rotate by hand every couple hours and repeat. Make sure to remove excess before replacing spark plugs, some people crank it with no plugs, no fuel relay so it doesn't hydrolock. Then before starting drain oil and replace. The Valvoline Restore & Protect is supposed to work good for that but takes at least 4 oil change intervals. I would recommend changing filter at about 2k and then cut open to see if a lot of junk is being removed that may clog filter and put it in bypass.

I'm also a fan of High Performance Lubricants EC30. It's an engine cleaner used in place of a regular quart of oil. Not a dump in before oil change and remove. Run as normal part of oil use. I have pictures of what carbon stuff it removed in my kids cars. Some people also say Rislone engine treatment at possibly double dose helps also for them.

Timing belt should be done as stated. Disable the VCM. The Valvoline is not expensive and easily available at Walmart. The HPL is mail order.

 

This has been very well documented as a VCM issue that is almost entirely reversible and these engines have very good longevity once VCM has been disabled.

You seem convinced otherwise, and this is a free country so I encourage you to do what you think is best once you've evaluated all of the information you can find.

Others have laid out the procedure and member @Nail Grease has posted an extensive rehab process that many have successfully completed.

 

Also, maybe any actual mechanics here can chime in- I always hear about ring gaps lining up. I understand when the engine is assembled (factory or rebuild) the gaps are offset as per the manufacturer. But does anyone believe that they stay there? Over 100K miles, with varying RPMs, loads, heat cycles, a dumb layman like me assumes the gaps migrate over time, sometimes lining up, and then offsetting again. Am I nuts? I just think it's funny how I always hear this mentioned as if people are surprised to see them lined up...
Cheers

 

Ring gaps lining up was Honda's BS excuse because they would not admit their VCM design in conjunction with low tension rings was the flaw.

 

Not only that, but it would be trivial for manufacturers to add a tiny, thin little tab in each ring land, 90 degrees offset from the one below. The ring could then only rotate the width of the gap, not all the way around. The fact that rings are not fixed in this manner (that I, the amateur are aware of) means that ring rotation is normal and expected, or at the very least, not detrimental.
But what do I know...
Cheers

 

Good information. I like to have the knowledge behind things, as although it was previously suggested I am already convinced, I am not. After watching the video and getting more input from the forum, I would suggest that getting the rings done and the ring seats(?) cleaned out gets you at or near original condition, and muzzling keeps the issue from reoccurring. I would think that's not an option for most due to cost at the very least, but if it is covered why not let someone do the job?

As for a chemical approach, my gut instinct is to assume it is not going to fix it as good as a tear down, and my experience with 3 Ody VCM engines confirms. I've always lost 1-2 quarts between changes, which is significant. In comparison, my daughter's 09 Escape (though not a Ford fan) doesn't lose a drop. As an Uber driver I do an oil change per month, so throwing in a couple extra quarts every time is something I'd rather avoid.

I thank everyone for their input. For now, I've done the plug, the coil, got some Gumout in the tank and a quart of Valvoline to top off the crank, and a DIY muzzle. It's due for an oil change so I'll do a clean, and the PCV is stuck so once I get that free I'll change it, though it's side mounted and I found those don't clog like the front mounted, so maybe not a concern. I'll update if/when things change.

 

but if it is covered why not let someone do the job?

Because you're trusting dealer techs to disassemble and reassemble a factory assembled engine. Certainly have been a fair number of cases where this was done improperly and led to further issues. I've even heard of people ending up with head gasket issues after. All for something unnecessary when just disabling VCM can get you to the same result.