Honda V6 rear bank stuck rings and using oil

[wwillson]

My weekly trip to Bill's shop yielded another interesting discussion with one of the mechanics.

He was working on replacing rear pistons/rings of all three of the rear cylinders on a Honda Odyssey van with about 125,000 miles on the clock. He said he does about one/month and it's always the rear cylinders that have stuck rings and use so much oil that the plugs get fouled. The front cylinders are always fine and have normal compression. This mechanic has about 40 years of experience and is serious about making a living working on cars. He can turn the rear bank piston replacement job in about 7 hours. It's fun to watch him work.

As far as he knows, they all run bulk oil and some owners neglect oil changes. Would a better oil help?

Why only the rear cylinders?

 

[Astro14]

Does this engine have the variable cylinder management? Where the ECM shuts off three cylinders?

 

[zfasts03]

I have an `06 Odyssey with VCM with 203,000 miles. Not VCM muzzled and just did the spark plugs for routine maintenance again. No signs of oil fouling on any of the plugs. The inside of the engine looks like a mess with sludge and varnish. I used quality oil (all brands) and it runs great.

This van has been through soccer mom duty hell. Short tripped like crazy, run hard and put away wet.

 

[Trav]

My weekly trip to Bill's shop yielded another interesting discussion with one of the mechanics.

He was working on replacing rear pistons/rings of all three of the rear cylinders on a Honda Odyssey van with about 125,000 miles on the clock. He said he does about one/month and it's always the rear cylinders that have stuck rings and use so much oil that the plugs get fouled. The front cylinders are always fine and have normal compression. This mechanic has about 40 years of experience and is serious about making a living working on cars. He can turn the rear bank piston replacement job in about 7 hours. It's fun to watch him work.

As far as he knows, they all run bulk oil and some owners neglect oil changes. Would a better oil help?

Why only the rear cylinders?

Disabling the VCM and running a higher >3.5 HTHS Euro oil goes a long way in preventing this issue. The older VCM Gen 1 had different issues than the Gen II.

 

[RooflessVW]

Why only the rear cylinders?

VCM and/or cheap oil and/or extended OCI.

 

[FranklinJL]

VCM does this 24/7......have to run something crazy to keep it varnish free. Mobil 1 0w40 for the win

 

[Warstud]

A piston soak wouldn't work ?

 

[RooflessVW]

A piston soak wouldn't work ?

Maybe? But that's a job for a DIYer, not a shop.

A shop doesn't want a car taking up space for days for minimal $

 

[dumkid]

i think the vcm cars that actually spend a significant amount of time running on 3 cylinders are the ones most likely to have stuck ring issues. if you drive it hard enough the vcm will rarely kick in.

 

[wwillson]

Does this engine have the variable cylinder management? Where the ECM shuts off three cylinders?

Yes

 

[Astro14]

I reckon a better oil would help.

But an appropriate change interval would be even better.

My brother has an Odyssey with that engine. Still has the VCM system intact and operating.

Changes it every 5,000 miles with Mobil 1.

220,000+ on the van. No issues.

 

[wwillson]

A piston soak wouldn't work ?

That's not the shop's deal. They only do what they know repeatably works. Experiments don't pay.

 

[The Critic]

The issue is most prevalent on the VCM motors from 2005-10, but on the Odysseys, up until 13-14. The newer ones do not seem to be affected, despite having VCM.

 

[Drew7a]

Hmmm. I see all the varnish and gunk on the front bank in these engines. I supposed that. Valve train condition foes not translate to the condition of the cylinders.

Another vote for 0w-40 or HM Mobil as those are proven to clean as well with 5K or less oil changes to keep things clean.

 

[I<3oil]

The issue is most prevalent on the VCM motors from 2005-10, but on the Odysseys, up until 13-14. The newer ones do not seem to be affected, despite having VCM.

The newer ones (5th gen) also use VCM 3 which apparently is showing some signs that it’s better than 1/2 but some are having issues on the forums still.

 

[NormanBuntz]

Another reason that I'm glad my 2007 Ridgeline has no VCM. And I've never done an oil change with less than 20% on the OLM.

 

[ls973800]

[QUOTE="I The newer ones (5th gen) also use VCM 3 which apparently is showing some signs that it’s better than 1/2 but some are having issues on the forums still.
[/QUOTE]

On the 3rd Generation Pilot Forum (2016-2022) there are reports of the VCM 3 affecting the 6 speed transmission torque convertor. The VCM 3 allows for "planned slippage" of the torque convertor at certain times to mask vibrations resulting from the cylinder deactivation. This is allowing the fluid to deteriorate quicker with wear material and eventually may cause transmission problems also.

Honda came out with a service bulletin to drain and fill the fluid 3 times and update the software if the new fluid didn't "fix" the problem. More and more reports of torque convertors needing replacement. What's somewhat odd in my opinion is that only the 6 speed transmissions which use Honda DW-1 fluid are having this problem.

The 9 speed transmissions which my 2019 Pilot Touring has uses Honda 3.1 fluid and there are no service bulletins for the same problem with that transmission. The Honda Maintenance Minder from owner reports calls for the 6 speed fluid to be changed about every 30000 miles but the 9 speed every 60000 miles.

 

[ctechbob]

I can somewhat confirm that it is mainly down to the VCM and not OCI's or oil used.

I'll explain my process.

My 2008 TL is a J-Series without VCM. The previous owner reported changing the oil by the OLM, but generally used quick lube places, so it probably got just bulk 5W20 for most of its life.

When I bought it, I did the timing belt/valve adjustment since there was no record of it being done and the car had 140k on it. The top end looks like crap. Oily sludge everywhere and a plugged PCV valve, yet the car doesn't smoke, uses no oil, and runs like a bat out of hell. I'm now at 186k and it still runs like a top. It gets 5K oil changes with Havoline HM 5W30 and probably the full syn 'Lifelong' 5W30 when I run out of the HM since I'm trying to get my oil stock down to one oil. I have run 5W20 in it and it still didn't burn any during the 5k OCI. I haven't really done anything to clean it up other than wipe what I could when I had the valve covers off and shorten up the OCI to 5K (40% on the OLM pretty much every time).

Pretty sure that a VCM engine of that vintage with the same OCI's would be a massive oil burner by now.

 

[OVERKILL]

Disabling the VCM and running a higher >3.5 HTHS Euro oil goes a long way in preventing this issue. The older VCM Gen 1 had different issues than the Gen II.

This. Your results with M1 0W-40 in these was pretty impressive.

 

[JHZR2]

I reckon a better oil would help.

But an appropriate change interval would be even better.

My brother has an Odyssey with that engine. Still has the VCM system intact and operating.

Changes it every 5,000 miles with Mobil 1.

220,000+ on the van. No issues.

Our odyssey oil change computer comes up around 5k, so that does seem to be the right interval.

I have had the van muzzled most of its life. Currently it isn’t, but I will again at some point (figure it’s good for the system to operate to some extent).

The engine is prone to some varnish, which is something I’m not used to. It has seen synthetic oils 0w-20 its whole life. Runs great and smooth. MPGs on on the highway (we can get 30 if super careful and zero traffic, usually 28), but poor around town.