mdh

I am getting close to purchasing a new 2013 AWD RDX. I am wondering if there is proven history on the VCM engine? When I was a kid the Cadillac had all kinds of problems with cylinder management. Is Honda or Acura using this engine and for how long? Good history? Thanks so much,

Mike_TX

I can't give you any assurances, but I can tell you one thing - Honda/Acura isn't using the GM engine! LOL.

In fact, I believe the Caddy engine used a purely mechanical actuator to deactivate cylinders, and Honda/Acura's is computer controlled. Of course, the computer tells the valve train to mechanically uncouple and hold the exhaust valves open, but with their modern OHC engines and variable valve timing and lift, the mechanism is already there to do the heavy lifting.

I think you're looking at a different animal from 1980's GM tech, and I figure Honda has done its homework with this engine. Furthermore, I think you'll see it in all their products before long.

Colorado Guy AF Ret.

Good notes Mike_TX. Honda Motor Corp. has perfected VCM since it's early days. And I see other's are looking to use the system too.... I believe Chevy is going to start using it...and maybe others. I'm sure their own design...but, hopefully better than the old Cad. system!! LOL!

mdh

Great to know.. which Hondas are using VCM? Any idea when they started to use them? Thanks so much...

Roadie2000

Can't comment much on the history, but the VCM is pretty seamless. I can't even tell when it kicks on, but I can usually feel a little jolt when it shuts off.

mdh

I found this

http://en.wikipedia.org/wiki/Variable_Cylinder_Management

BlackDogRDX

I would strongly suggest searching the forum for the low rpm vibration. It's not necessarily hand-in-hand with the VCM but it's certainly closely related as the tranny was likely geared in such a way as to maximize MPGS.

Mike_TX

I thought that got resolved awhile back. My RDX (2/13 build) doesn't have any sign of that.

Colorado Guy AF Ret.

Hey, great job on finding the answer. I was going to write you and let you know I would have to research it. That Wikipedia article is good....giving all the Honda's that use/used VCM.
I had it on my '12 Accord Cpe. and it was smooth. It dropped from 6 to 4 to 3. Now they are just dropping one time.

Dorsey

Acura says the 2013 RDX VCM is 6 or 4 or 3 cylinders http://www.honda.com/newsandviews/ar...spx?id=6556-en
The citation for the Wiki "fact" that it only operates on 3 or 6 cylinders is a Honda press release about the 2013 Accord which does not mention the number of cylinders deactivated by VCM. That statement was added by the website that posted the press release.

Colorado Guy AF Ret.

I just got the VCM clarified for myself....and I should have known better.

For Honda engines..in '08 thru '12 V6 engines...VCM operated 6 to 4 to 3 cylinders. In 2013 the engine was completely gone through and many issues were changed...and one of them was how VCM operates. It's either 6 or 3 cylinders.
Honda Media Newsroom, dated 9/5/12.

Ironically, the '13 Acura VCM engine is 6, 4, or 3 cylinder operation. Wonder why we didn't get the Honda version?
Anyway...I'm straight now! And I'm an engine guy from way back. Taught Tech School even! I'm bad!

Ken1997TL

I'm guessing the RDX needs more torque at mild loads, therefore necessitating the 4 cylinder mode.

Dorsey

AF Guy - Well, now I am confused. My understanding has been that the 4 cylinder mode was added in 2011 or 2012 to enhance smoothness. Motor mounts were also changed. In any event, Honda says the 2013 Oddy has 3,4 and 6 cylinder mode http://automobiles.honda.com/odyssey/environment.aspx Please post a link to the 9/5/12 article. Thanks.

Colorado Guy AF Ret.

http://hondanews.com/channels/honda-automobiles-accord

You can go to Honda.com and find the link ups there also and to http://www.hondanews.com/channels/acura-automobiles-rdx for the Acura RDX stuff. Has 6 pages on the RDX powertrain!! Interior is another section...many pages of details. Stuff you don't find in our Owner's Manuals.

The '13 Accord site is very detailed on all issues of the 2013 Accord. Go to the VCM Operation section and that's where they explain about the 08 thru 2012 Accords, etc, etc. And they do a great job of explaining VCM operation. Quite detailed in explaining how they use oil pressured spool valves controlled by ECU commands. Yeah...too heavy for most of us to truly get into....but, overall it's good info. to learn about our engines. Some will like it, other's could care less.....and that's OK. This is for those that want to learn more.

saxman48

Good stuff indeed. However, you can't believe everything you read. The interior section states

"All four doors have courtesy lights that illuminate when the doors are open. "

For the life of me, I cannot find the courtesy lights on the two rear passenger doors. To be honest, I had discovered this before I bought the car and it was not a deal breaker, but a disappointment for sure... My 2006 Honda Ridgeline truck has courtesy lights on the rear doors, as does our 2006 TL... Based on the write-up, I'd say Acura may have originally planned having these lights but then changed their mind without notifying their pubs people.

Colorado Guy AF Ret.

Somewhat surprising since the Honda News Release was dated right at the time the RDX's were ready to show up at dealers. For Acura, the rear door lighting is kinda normal for them. My '13 TSX has them. But, my educated guess is that 99% of the info. is correct...and that's based on comparing what it says and what mine has.....and also I believe the engine info. is correct. That info. is backed up by everything I've read about the Honda engines and the RDX engine.

Honda wouldn't be making such a big mistake talking about engines that "were produced" in the past. And, then hyping the big change in the upgrades to the '13 Accord engine including the VCM changes.
IMHO.
Take care!

mdh

thanks everyone... so.. net-net, the engine technology is "proven" and no longer a technical experiment since Honda has been fielding it for a while...

Ken1997TL

Correct. Hundreds of thousands of six cylinders have been produced with it. Noise, vibration are minimal and nearly imperceptible. Reliability is unaffected.

tegraphile

So I'm hearing the consensus is longevity is NOT affected by VCM?

Gadgetjq

Until your question nobody had added to this thread since 2013 so, yeh....not an issue.

Cheers!