Honda Odyssey Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1 (Edited)
Hi all, first post from a longtime lurker- thanks for years of advice. Skip the first two paragraphs to jump right to current symptoms.

Background: Two years ago my 06 threw a code combination like Random Misfire + Cyl 1,2,3,4,5,6 misfires. Odd, we thought, not having noticed any misfiring, other than a slightly rougher idle than ideal. I cleared the codes and we drove on. Codes returned after a week or a month, and my wife refused to drive the van further until we fixed it. Fair enough; I may have... nuked... the catalytic converters driving one of our previous vehicles through misfires.

So not knowing the history of the car (bought it used with 100K+ miles) I did all of the easy stuff I knew to do at the time: I replaced the coils, plugs, and the EGR and PCV valves. The problem seemed to go away, and I was a hero. Earlier this year, the codes came back and then the car abruptly died or almost died during idle while my wife was driving, and we took it to the mechanic for diagnosis. The timing had jumped multiple teeth, to the extent they were surprised. They fixed and replaced various timing components, but they were concerned about valve damage and wanted something like $1200 to inspect the valves, which I declined.

Now, five months later, the random + all-cylinder misfire codes have returned. I pulled the coils and plugs again (only 25K miles since 2018 replacement). Plug #1 (rear left, looking into the engine compartment from the front) is black + residue, internet says oil fouling?. All other plugs look the same- white tops, minimal residue. Internet searches say maybe they are fine, or all running slightly lean/hot? Coil packs look great. PCV and EGR valves still look good. Buying some parts at auto store the guy suggested I replace/check the IAC valve... which I think the 06 ody does not have (please correct me if wrong). While I had the plugs out, I decided to run a cold compression test. I pulled the Fuel Pump fuse in the driver's fuse box and the FI fuse in the engine fuse box, but I forgot to leave the throttle open.

Cylinders 3,4,5,6 all gave max compression of ~220 PSI. Cylinders 1+2 gave 155-165 PSI. So I did the wet compression test, squirting 5ml (1 tsp) of 10W-30 into the plug holes with, I kid you not, a childrens tylenol syringe. Wet compression on #1 and #2 now gives 220 PSI and 195 PSI, respectively. The internet says a significant jump in PSI with the wet test = worn piston rings. Internet also says Honda probably forked me with VCM, and I'm now long past the warranty on getting that fixed for free. I called a dealer and they ran my VIN and confirmed they aren't going to cover it.

I have a few questions, now:
1. Are my results still useful, even though the throttle was closed and the engine was cold when I ran the tests? i.e. is piston rings still a valid diagnosis, or should I re-run the tests again with the throttle open before anything else (not sure if the oil from yesterday is now going to throw off my results)?
2. Should I still pursue other threads I was thinking (valve adj., injectors, etc.) given that the misfires were reported as random and all cylinders (not just 1+2)?
3. Anyone had success getting a dealer to do the VCM/re-ring job out of warranty?
4. Piston ring replacement is probably more $ than the car is worth; can I drive it like this or am I risking damaging the engine or something something dangerous?
 

·
Registered
Joined
·
2,044 Posts
Other experts here will help you with your issue and compression data.

I suggest you install a VCM muzzler device to disable the VCM function. This has the potential of improving your piston ring issues, preventing misfires, excessive oil consumption, premature failure of engine mounts, etc...
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
Other experts here will help you with your issue and compression data.

I suggest you install a VCM muzzler device to disable the VCM function. This has the potential of improving your piston ring issues, preventing misfires, excessive oil consumption, premature failure of engine mounts, etc...
Is there one for the 06? PM me a link?
 

·
Registered
2006 Honda Odyssey (EX)
Joined
·
218 Posts
  • Like
Reactions: NathanDetr0it

·
Registered
Joined
·
4 Posts
Discussion Starter #5
Get the VCMTuner II from vcmtuner.com. Make sure you get the one for 05-06 models.
Thanks, is this the one you use? How do the 'adjustments' work (I see this one has a variable resistor).

Also, update: I'll be re-running cold compression tonight with the throttle open, will post updated results.
 

·
Registered
2006 Honda Odyssey (EX)
Joined
·
218 Posts
Thanks, is this the one you use? How do the 'adjustments' work (I see this one has a variable resistor).

Also, update: I'll be re-running cold compression tonight with the throttle open, will post updated results.
I don't have a VCM Ody. This is just the best on the market.

The one with the variable resistor is the VCMTuner. It's better to get the VCMTuner II as it allows you to replace the motor mounts with the cheaper passive ones (you can't do this with the original VCMTuner since it doesn't disable 100% of the time) and is a set it and forget it type device, because it never requires adjusting. It's a bit more expensive, but I think it's worth it.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #7
UPDATE: Holding the Gas Pedal down made no difference in our cold compression results. So, it's new OEM NGK spark plugs, Seafoam in the tank and intake, and the VCMTuner II for this round of repairs. If this problem recurs even with VCM disabled, I will probably proceed to the valves and injectors.
 

·
Registered
2006 Honda Odyssey (EX)
Joined
·
218 Posts
UPDATE: Holding the Gas Pedal down made no difference in our cold compression results. So, it's new OEM NGK spark plugs, Seafoam in the tank and intake, and the VCMTuner II for this round of repairs. If this problem recurs even with VCM disabled, I will probably proceed to the valves and injectors.
Hope it helps. If it solves your misfire, I don't see any potential issues driving around with damaged piston rings, as long as you top up the oil when needed, and the VCMTuner II may very well improve that as well.

I've been driving my Accord for more than 70k miles with dirty piston rings that were consuming oil. I've been adding a quart every 1k miles, and so far it has held up with no issues.
 
  • Like
Reactions: NathanDetr0it
1 - 8 of 8 Posts
Top