Why Cylinder Deactivation Can Cause Engine Failure (Honda)

[92SL2_oilburner]

Food for thought...

I believe there is one other reason why cylinder deactivation is required in addition to just turning the fuel injectors off. Yes, there is a pumping loss effect with cylinder deactivation. Another big effect (from Honda’s emission point of view) is that they don’t want any extra air (oxygen) going through the common catalytic converter because it would then behave like a “lean burn” system and NOx conversion would drop to zero. NOx does not convert within a catalytic converter in the presence of high oxygen levels due to chemistry.

In a nutshell, Honda could never meet emission regulations for NOx in “fuel economy” mode if the rear cylinders pumped air through the common catalyst shared by front and rear cylinder banks.

 

[pezzy84]

My parents have a 3rd gen Pilot (2017 or 2018) with a J35 with VCM. I'm curious to see if they run into issues down the road as they are not gear heads and just want a car that works, they run maintenance minder down to 5-10% and get it serviced at the Honda dealership. They have run their past 2 Pilots (1st and 2nd gen - non VCM) to 200-250k miles so hopefully this one will keep par for the course.

 

[circuitsmith]

In a nutshell, Honda could never meet emission regulations for NOx in “fuel economy” mode if the rear cylinders pumped air through the common catalyst shared by front and rear cylinder banks.

Also, it would be cool air, which might stop the converter from working at all.

 

[kstanf150]

Yes, cylinder deactivation is total junk. A previous co-worker of mine had a Honda with this feature and it had major problems with very few miles on the engine. The C-7 Corvettes have had problems with this as well and other GM pickups, Cadillacs and other vehicles. It just doesn't seem to work that well.

The company I work for has four GM SUV’s with cylinder deactivation

They drive like total JUNK !!!!
Two are Cadillac’s
110K dollar junks !!!!!

 

[Blinker]

I’m not sure what to believe regarding the Honda VCM engines. My cousin bought a 2008 Accord EXL V6 new in 2007 and he drove it over 200,000 miles with NO engine issues and NO oil consumption. I do remember that car having a lot of brake and battery issues is all.

I wonder if driving style has a lot to do with it. My cousin drives with a lead foot, it’s possible driving these engines hard keeps the piston rings free and valves rotating properly.

 

[Blinker]

FWIW, the GM 3.6 LGZ in the Chevy Colorado/GMC Canyon has cylinder deactivation and it’s imperceptible.

I rented a 2020 Chevy Colorado and drove from Dallas to the Florida panhandle. On the way back to Dallas I was toggling through the instrument panel menus and one of the menus told you if the engine was in “V4 Mode” or “V6 mode”. I would have never known that engine had cylinder deactivation because you cannot feel it. I got 26-27mpg on that truck doing 70mph. I think cylinder deactivation is perfected in some engine.

 

[BlueOvalFitter]

You forgot to add "with the least amount of R&D and cost". GM has been using the technology for years no?

My ex-FIL had an 80's Cadillac with that garbage in the engine. Biggest POS I ever drove.

 

[Propflux01]

I am surprised that it doesn't use variable cylinder cutoff instead of just the same three. Seems you would want the block to be evenly heated.

 

[doublebase]

Yes, cylinder deactivation is total junk. A previous co-worker of mine had a Honda with this feature and it had major problems with very few miles on the engine. The C-7 Corvettes have had problems with this as well and other GM pickups, Cadillacs and other vehicles. It just doesn't seem to work that well.

I agree, I will say that GM has “improved it” somewhat in their pickup trucks. You don’t see the lifter failure as much, however it still can happen and the real damage occurs in the transmission because of the constant shifting back and forth as the engine goes from V8 to V4. Lot of torque converter failures too.

 

[Jake_J]

Honda's VCM system on the J series V6 is very reliable and is not known to have issues. Cylinder deactivation when done right is seamless and ends up saving the owner a lot of money in fuel savings. I think most people here when they hear of cylinder deactivation they think of the problems that GM had with their system and assume the whole concept is junk which is just plain false. Mercedes has been using cylinder deactivation since the 90's without issue, Chrysler since 2004, and they are not known to be an issue. In addition Ford, VW, and Mazda are all using cylinder deactivation again without issue. I think toothbrush guy and several folks here are cooking up a classic nothingburger.

 

[Trav]

Honda's VCM system on the J series V6 is very reliable and is not known to have issues

You are very seriously misinformed or own one of these and don't want to admit you you bought a real pig in a poke.

 

[PimTac]

I am in the camp that regular oil changes with quality synthetic are crucial for these engines. Those who don’t change their oil on a regular basis just ask for trouble.

 

[Driz]

I agree, I will say that GM has “improved it” somewhat in their pickup trucks. You don’t see the lifter failure as much, however it still can happen and the real damage occurs in the transmission because of the constant shifting back and forth as the engine goes from V8 to V4. Lot of torque converter failures too.

GM invented it 40 years ago ! If after all that time it’s still unreliable long term it tells you something

 

[Snowflake White]

You can actually have this "feature" deactivated PERMANENTLY though the CANBUS system, I'd definitely have it disabled if you have this engine. The only change is you MIGHT lose a few tenths of MPG, and the engine will be perfect for the long haul.

TURN THIS OFF!!!!

 

[Trav]

I am in the camp that regular oil changes with quality synthetic are crucial for these engines. Those who don’t change their oil on a regular basis just ask for trouble.

To add to that these engines not only need frequent oil changes but do better with a full synthetic (it doesn't need to be a fancy boutique oil) oil.
The older non VCM engines were much easier on oil and a much better engine in every way, a true gem of an engine and one of my favorites, I just wish I could say the same of some of the earlier transmissions.

 

[Trav]

You can actually have this "feature" deactivated PERMANENTLY though the CANBUS system, I'd definitely have it disabled if you have this engine. The only change is you MIGHT lose a few tenths of MPG, and the engine will be perfect for the long haul.

TURN THIS OFF!!!!

Not on the Honda.

 

[SatinSilver]

My parents have a 3rd gen Pilot (2017 or 2018) with a J35 with VCM. I'm curious to see if they run into issues down the road as they are not gear heads and just want a car that works, they run maintenance minder down to 5-10% and get it serviced at the Honda dealership. They have run their past 2 Pilots (1st and 2nd gen - non VCM) to 200-250k miles so hopefully this one will keep par for the course.

The MM shouldn’t go any lower than 15% on these as a worst case scenario. Change oil every 6 months/5k miles using a higher tier synthetic like M1 EP available at Walmart. Check oil level often. These are some of the common thoughts on the Honda forums that I used to frequent.

 

[Hillbilly Deluxe]

You forgot to add "with the least amount of R&D and cost". GM has been using the technology for years no?

You say that like GM is some great power of automobile manufacturing and reliability.

 

[Hillbilly Deluxe]

Honda took possibly one of the best and most reliable V6 cylinder engines ever made and turned it into a piece of trash with this to save very little.

Honda also screwed up the world's best 4-cylinder (Mid 2000's era) 2.4L engine in 2011-2014.

It boggles my mind why these hugely successful companies let some hair-brained, highly-educated, poorly experienced "engineer", accountant and marketing people come into their companies and basically destroy them in one fell swoop with some stupid conference room meeting idea.

 

[Trav]

My parents have a 3rd gen Pilot (2017 or 2018) with a J35 with VCM. I'm curious to see if they run into issues down the road as they are not gear heads and just want a car that works, they run maintenance minder down to 5-10% and get it serviced at the Honda dealership. They have run their past 2 Pilots (1st and 2nd gen - non VCM) to 200-250k miles so hopefully this one will keep par for the course.

I wouldn't bet on it. Change the oil with full synthetic Mobil 1 0w40 or 5w30 ESP at half the OLM to give the engine half a chance for a long life.
These VCM engines are notorious. IIRC I was one of the first to run into the issues and actually tore into the engine for a look see and repair, that was many years ago but posted here and took a lot of flack from the Honda gang.