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Honda Accord VCM

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Comments

  • robertsmxrobertsmx Member Posts: 5,525
    Active engine mounts are quite common now. You will find those in Lexus too.
  • rockdoctor1rockdoctor1 Member Posts: 10
    4000 miles on my EXL V6 Coupe, and let me say right off I love this car. I came from a 2000 EXL V6 Coupe, and I definitely noticed the VCM at times. I'd call some VCM engagements seamless like at the end of acceleration, but occasionally you get reminded that there is a computer trying to figure out what you're trying to do with the throttle. I found that I can manage VCM on/off when I want it by manipulating the sensitive throttle. I find it particularly useful when in backed-up interstate traffic, or waiting through stop light cycles. By accelerating, to a desired speed then sort of backing off quickly, the VCM kicks on and the tranny stays geared low and then I can slowly accelerate into higher than normal rpms without changing gears. It makes it easier to stay off the brakes which to me is the ultimate traffic de-congestion solution btw. I think I can tell there is a computer trying to figure out what driving condition I'm in and what is the best combination of gear, rpm, and # of cylinders to get what I want most efficiently. Most of my driving has been on flat topography, but even on small Birmingham foothills, it was fun figuring out the best way to save fuel and have fun doing it.

    It definitely has me thinking about better mpg more than I ever have.
  • robertsmxrobertsmx Member Posts: 5,525
    Looks like I'm not alone when it comes to "trying to figure out" thing. :)

    Thats also the beauty of most Honda designs. It allows folks to discover things and often take control and use it to their advantage.
  • thegraduatethegraduate Member Posts: 9,731
    You in Bham Alabama? Glad to hear you like the coupe!
  • blufz1blufz1 Member Posts: 2,045
    I think that VCM is a good idea......on paper. I just prefer a more simple approach,like diesel. I really doubt VCM will provide any real advantage over your 6 manual,net of the increased weight, frontal area, and displacement on the '08. Tendonitis in my right elbow (Bass Fishing) precludes me from getting a 6 speed car. Now all my shifting is done on my 150 mph,11 second 1/4 mile, 6 speed Yamaha FZ1 motorcycle. :)
  • robertsmxrobertsmx Member Posts: 5,525
    VCM has VTEC. Diesel has high pressure turbo and intercooling system. So, complexity can't be avoided.
  • blufz1blufz1 Member Posts: 2,045
    I would rather have the V6 straight up simple with no VCM. Read some place that they had to redesign the motor mounts because of increased engine vibration in 4 or 3 mode. That's a deal killer for me, I'll just do a diesel. Diesel is actually perfect for bass boat towing and launching.
  • bug4bug4 Member Posts: 370
    The question then becomes whether an Accord, even with a diesel, is perfect for bass boat towing and launching :P
  • robertsmxrobertsmx Member Posts: 5,525
    Active engines mounts are gaining popularity to improve NVH characteristics from the engine. So, it can (and does) exist without VCM. Honda calls it Active Engine Mount. Lexus calls it Active Control Engine Mount.

    If Honda chooses to make the Accord Diesel smoother, they might choose to use it in that model as well.
  • blufz1blufz1 Member Posts: 2,045
    Well, I'm the one who would know best for my purposes. :)
  • blufz1blufz1 Member Posts: 2,045
    Know that. I'm referring to the inherent increased vibration in the engine when running in 3 or 4 mode vs. straight up V6 mode.
  • golfrskigolfrski Member Posts: 262
    ahhh so I am not alone!!! Thanks rockdoctor1.
  • robertsmxrobertsmx Member Posts: 5,525
    You mean different harmonics. But, active mounts are designed for just that... kill harmonics (of any kind).

    Remember, all pistons are still running even in I-3 mode. The extra vibration comes only from lack of burning fuel on one bank (not so much in 4-cylinder mode, since it is actually a V4 layout).
  • rockdoctor1rockdoctor1 Member Posts: 10
    I forgot to post my mpg history. Tanks 1-7, all about 70% hwy @ 74 mph.

    26.63
    26.64
    26.78
    27.31
    27.20
    27.38
    26.67

    Funny, my 2000 3.0l V6 Accord got 28 mpg the first tank and 28 mpg at 196K miles. However, I doubt my 16 yr old daughter gets 25 mpg the way she drives it now.
  • blufz1blufz1 Member Posts: 2,045
    No. I mean what I said. I don't want the engine to vibrate more than it has to. The engine vibrates more in 3 or 4 mode. I don't care that the active motor mounts tune this vibration out from the passenger compartment, I don't want the engine vibrating more than it does in V6 mode. It's probably not best for longevity.
  • robertsmxrobertsmx Member Posts: 5,525
    Then you should ask for V8 diesel. :D
  • blufz1blufz1 Member Posts: 2,045
    I'm not denigrating Honda. I just prefer simple vs. complex. My next car may be a CRV diesel. You know, inline vs. V. :)
  • bug4bug4 Member Posts: 370
    I'm actually with you blufz1 . . .I don't blame anyone for wanting the v6. But, I drive my Hondas for 8-10 years and I decided I didn't want such a complicated engine / motor mounts. What actually scared me more than the durability of the engine and mounts, was the complexity of the control module for this system. I understand the non-VCM modules cost several thousand to replace. Imagine what that VCM module might cost if it failed. I admit, I've very conservative on this point and I certainly don't criticize anyone else for choosing the v6 . . .
  • colloquorcolloquor Member Posts: 482
    "VCM has VTEC. Diesel has high pressure turbo and intercooling system. So, complexity can't be avoided."

    A high-pressure turbo and an intercooler may be a complex system, but a tried and true system as SAAB initially used this system in the early '80s SAAB 900 Turbo. It's a very reliable design, and a high-pressure turbo will easily reach 150K miles without a failure if one changes oil regularly and uses a quality oil in the first place - and, not shut the engine down immediately after high-speed operation, so that you don't cook the oil out of the turbo's bearings.

    Diesels, especially those used in over the road trucks, have been using this design for many years, and it's truly a reliable solution. I think some are just concerned with the long-term reliability question of the VCM system.
  • robertsmxrobertsmx Member Posts: 5,525
    VTEC has been around for a long time too. I wouldn't bet against it.

    Like every technology, it has evolved over (now) two decades, with VCM feature added five years ago. Diesels aren't the same old thing either. A lot of complexity has been added besides turbo/intercooler. You can't compare today's diesel to diesels from two decades ago, could you? One could even argue against the new catalytic converter, the new casting techniques, the common rail design and so on.

    But if we were to be wary of every new development, we might as well stick with a Model-T. I'm sure it didn't have the engine mounted even on a subframe, much less an active control/hydraulic mount. :P
  • rgf42rgf42 Member Posts: 4
    How does VCM work?
  • robertsmxrobertsmx Member Posts: 5,525
    In addition to post #42 above, here is a bit more.

    VCM uses VTEC. Honda has been doing something similar for ages that a lot of folks probably don’t know about. That would be selective opening/closing of valves. In these applications, at low engine speeds, the 4-valve/cylinder engine in the four-cylinder Accord operates in 2-valve/cylinder mode. One intake and one exhaust valve are kept shut. This design has been used in several engines (including Honda VFR where it is called Hyper VTEC).

    VCM takes the same idea a bit further by not closing two of four, but all four. It is about as simple an idea as it can get. This was used in cylinder idling system in first generation Civic Hybrid as well. Unlike VCM which operates under a variety of situations, the cylinder idling system shut three of four cylinders only during deceleration.

    There are downsides to VCM, however, and one of them is due to the fact that it is applied to an engine design that wasn’t designed around it. It has limited the choice of cam profile. Unlike normal circumstances, VTEC can select between two cam profiles, one for low rpm performance and the other for mid-high rpm performance. By limiting to one profile, the engine now becomes more like one without the VTEC advantage in terms of performance. The performance aspect has been replaced by VCM aspect.

    This is the reason Accord V6/VCM feels a bit softer in low-mid range (than non-VCM version of the engine) since its cam profile is better suited for high rpm performance. This would also be the reason for Honda’s choice to choose 3.5-liter engine over 3.0 or 3.2-liter in Accord. With that little compromise, the car still has the performance of being powered by something like a good 3.2/V6 in low-mid range for around town driving, while also benefiting from VCM in terms of fuel economy. For highway passing power, 3.5/V6 power would be available.
  • golfrskigolfrski Member Posts: 262
    This has REALLY become some great dialog around VCM technology and comparisons everyone. I did some more test driving in my 08 V6 today. I notice the car surging a bit at the 45 mph range (keeping at that consistent speed) and still at 65 and 70. Still not used to it and hoping it will grow on me. Headed out for a 3 hour highway drive tomorrow and will report back in on my experience now that am at about 1200 miles logged.
  • robertsmxrobertsmx Member Posts: 5,525
    At 45 mph, it is likely the grade logic at work (car will operate in fourth gear under 40-45 mph at all times, and will go up to fifth only beyond that).
  • manybmwsmanybmws Member Posts: 347
    Try using cruise control if possible as well. I find that this can be a good way to feel the effect of various throttle and transmission settings made by the car's electronics...and of course VCM.
  • bug4bug4 Member Posts: 370
    Cruise control is an interesting issue. I just finished a 900 mile trip last weekend in my 08 EX-L I4. I learned a whole bunch about the car on the trip! Of course, my 4 banger doesn't have VCM technology.

    I messed around with the cruise control a lot during the trip. I found that my 5-speed auto tranny makes worse decisions about when to shift while under cruise control then it does when under the control of my own foot. The cruise wants to maintain speed and so the transmission often downshifted to prevent any loss in speed. When controlling the throttle myself, I was often able to keep the car from downshifting, while only loosing 5-7mph on a hill. Even beyond the issue of downshifts, I think the grade-logic simply works better when it gets the input of the human foot, rather than the single-tracked "mind" of the cruise control.

    My point is that you might be able to better evaluate the VCM system when the car is making fewer transmission shifts. So, at least in my experience, you might want to keep the cruise off.
  • rgf42rgf42 Member Posts: 4
    How does VCM work part 2. Are the lifters electric and stop working like the late 70s Cadillac 248 or whatever it was?
  • ezshift5ezshift5 Member Posts: 858
    .....My point is that you might be able to better evaluate the VCM system when the car is making fewer transmission shifts. So, at least in my experience, you might want to keep the cruise off.

    ....your point is well taken. In fact, your entire post was right on the money, IMHO.

    What I can't figure out: Why is an obviously clued in hombre like you driving without triple cone synchros, a clutch and a vertical shaft that does more than offer lip service to poseurs (forgive the spelling:don't use that word very often)

    Seriously, good post!

    best, ez....
  • robertsmxrobertsmx Member Posts: 5,525
    I rarely use cruise control, and less so on long distance driving if the car happens to be a Honda (or similar). With some other cars, I am forced to use cruise control however, largely due to the way they set up the gas pedal (Toyota is a good example). In a Honda, I can rest my feel with throttle opened as much as I want, and it “accepts” it and doesn’t react by pushing my feet the other way. OTOH, in many other cars, the pedal has a spring action that literally challenges for a wrestling match (and won’t maintain speed if you take the feet off).

    Based on my observations, Honda’s cruise control and transmission shifts tend to be firmer for first few thousand miles and they either learn or seem to settle down after that. You might notice a few things turning smoother around the time you get the first oil change done (around 7500 miles?).

    BTW, I will also recommend to not replacing the original oil at least thru 5000 miles, and this may be mentioned in owner’s manual. Most of us seem to focus on break-in as something about throttle usage, but rarely about impact on brakes and oil. It might be better to keep an eye on it though, around 3000-4000 mile. If it is in good condition, keep going.
  • robertsmxrobertsmx Member Posts: 5,525
    VTEC uses electronically controlled hydraulics. With VCM, the only difference is that the idea is to shut down all valves on selected cylinders using VTEC. It adds spool valves to select cylinders and additional commands in the ECU/PCM. Here is a summary:

    - In I-3 mode, valves on all cylinders on the rear bank are shut down.
    - In V4 mode, valves on right outer cylinder in the front bank and valves on left outer cylinder in the rear bank are shut down (I may have front/rear bank switched).
    - At the time the ECU issues the command to shut down the cylinders, PCM cuts off the fuel supply to those cylinders. However, the spark plugs still ignite (to keep the cylinders warm and ready). The pistons still move in the idling cylinders. The only thing that isn’t happening is intake of air, injection of fuel and the rest of the process.

    As I had mentioned earlier, in non-VCM designs, Honda has used VTEC to shut down half of the valves in each cylinder (one intake and one exhaust) at lower engine speeds. This is being done even in 2.4-liter I-4 Accord that is PZEV rated. The same has been done to improve performance as well. In motorcycle world, Honda calls it “Hyper-VTEC”, used in VFR. Interestingly enough, this design pre-dates VTEC moniker. It was launched as REV in 1983 Honda CBR400F. And REV was really the beginning of VTEC which was launched six years later in cars (beginning with NSX, in 1989).

    VCM takes that original 2-valve or 4-valve set up from REV to 0-valve or 4-valve set up.
  • bug4bug4 Member Posts: 370
    Frankly, I'm flattered! I don't think anyone has ever called me an "obviously clued in hombre."

    I got the auto tranny for funny reasons (it is the first auto I have ever owned in a non-SUV). The dealership gave me an outrageous deal on my 98 Accord, such that I didn't want to give them much time to reflect on their offer. If I agreed to buy an 08 off their lot, they also gave me almost 1000 off of MSRP and threw in the auto-tranny and a spoiler for free. (The auto was free because I told them there was no way I would pay for something I REALLY didn't want). It seemed like a no-brainer to me . . .I loved everything about my 08 EX-L silver w/ black leather, except the auto transmission. I test drove it many times and found the auto to be very impressive ---for an auto! I test drove everything under $35k and found the Honda auto to be superior to any other brand. Finally, although I have always driven my cars for 8-10 years, I had intended to purchase the Acura TL when I saw the Honda - so I'll be taking a serious look at the redesigned TL in 2009-2010. I figured an auto, 4 banger is the easiest to unload without as much depreciation.

    I'll bet that's more than you wanted to know . . . thanks again for the compliment! :D
  • manybmwsmanybmws Member Posts: 347
    Rumor is that there will be an Acura Coupe coming out along with a new 4-door TL next year. I am assuming these cars will share platform technology with the '08 Accord designs but my guess would be without VCM. Possibly have AWD also.

    Obviously $5 - 7K or so more but might be worth the wait...
  • sr1945sr1945 Member Posts: 38
    Fo me....

    Had to make a choice for my 08 Accord w/NAV purchase as to whether the V-6 or the 190 hp I-4 would be best.

    Gave this some thought about VCM and decided that since I will be only using 4 cyl instead of the V-6 on the highway, unless passing or going up hill, It would be a waste of a good money purchasing the V-6. Saved the money, and happy with the decision and find no issue passing other cars on the highway.
  • golfrskigolfrski Member Posts: 262
    Well........... Just got back today from over 5 hours of highway driving in the 08 EXLV6. I remain steadfast that the VCM 3-4-6 config is poor in feel. This is "my opinion" I have owned 6 accords 4 V6's and NONE felt like this car. I tested the car at about every speed I could and still feel surging and hesitation in consistent speeds marks 65 70 and 75mph. The car continues to try to find "something" , Frankly its enough to make you nauseous. If you are not an avid driver (i.e like performance and are automotivley aware, then do the 4 cylinder and forget about the VCM. I am sorry, but Honda may have just punched out alot of cars that will be headed back to the dealer with some owners scratching their heads in dissapointment. I will say that I am planing on having the car looked at again by Honda to see if my particular car is having "other" issues and of course will report back...to the forum. I hate to say, I am hopeful its an issue with my car only.
  • robertsmxrobertsmx Member Posts: 5,525
    The issue can't be that bad. Honda has had VCM for five years now, and most Odysseys in my neighborhood (and thats a lot of them) have it (introduced with the redesign three years ago).

    Where do you live? While I could go to a dealership to experience one, I would rather see it work in a friend's car (if I can call you that) over different situations.
  • kiawahkiawah Member Posts: 3,666
    That's what I thought about the 07 Camry as well. Same sound 4 cylinder 5 speed.....that they managed to mess it up big time with different software configuration that enabled hesitation, poor performance, and cruising problems. After 2 TSB's and a year later, finally running good!
  • golfrskigolfrski Member Posts: 262
    It appears this is going to become a REAL problem.. I'm not alone. this really sucks!

    http://www.driveaccord.net/forums/showthread.php?t=13506
  • golfrskigolfrski Member Posts: 262
    and more bad news...........

    i am so bummed out right now.. I waited for this car for 2 years and was so excited when I picked it up. I have a sick feeling now that I have what will become a nightmare on my hands,, someone walk me off the ledge! how does one return a car they just bought with 1100 miles ?? :-( I bought the 2003 V6 the 1st month it came out and never had any 1st gen issues.. i loved that car and now really miss it.

    http://www.vtec.net/forums/one-message?message_id=713706&page_number=1
  • golfrskigolfrski Member Posts: 262
    More people experiencing the new VCM engine issues of surging and vibration on the links below.

    Honda must do something to remedy this as more owners come forward or I predict V6 sales to suffer as people learn of this operational concern. I trust that Honda will find a solution and do the right thing to make the VCM issue/s go away and/or completely transparent. At least I hope they will.

    http://www.driveaccord.net/forums/showthread.php?t=13506

    http://www.vtec.net/forums/one-message?message_id=713706&page_number=1
  • robertsmxrobertsmx Member Posts: 5,525
    Some of the folks providing comments don't seem to have a clue or two about things. I wouldn't weigh too much into that. One guy who commented on ANC making noise, is one of the utterly clueless ones. If that were an issue, then at least a few of Accord EX/EX-L, Acura TL-S and Acura RL would show those signs too (none of them have VCM but they all have ANC).

    That said, I'm sure it can be felt a bit (like transmission shift can be, especially with colder weather).
  • elroy5elroy5 Member Posts: 3,735
    Sorry golfrski, but repeated posts on this forum will not solve your problem. You need to talk to your dealer service manager, and American Honda, if necessary, to solve this issue. We cannot fix this, as much as we would like to. :( Good luck to you on getting this issue taken care of. :D
  • patpat Member Posts: 10,421
    You are right we cannot fix it, but we can certainly provide a forum for discussion and that's what we've got here. Let's let golfrski and anyone else have his or her say about it, 'kay? :)
  • ezshift5ezshift5 Member Posts: 858
    ....De Nada. In keeping with the concept of 'virtue is its' own reward' - - - it is indeed pleasant to recognize positive post content.........

    ....I wuz tempted to do the same thing for another poster - - - - then a sparkling post concluded with a preposition (so my praise remained undelivered and elroy got zinged by the mod for a non-grammatical effort)....

    ...actually, this board is fun and has a lot of positive attributes....

    best, ez...
  • hpowdershpowders Member Posts: 4,330
    Very sorry to hear this. I know it's a hassle, but I would go back to the dealer and insist on driving several EX V6 demos to see if what you feel is "consensus" or a rare "fluke."

    Since all professional reviewers of the EX V6 have mostly praised the car with no hint of hesitation or surge that you describe, this leads me to believe you bought one with a rare but annoyingly real "bug" in the VCM mechanism.

    CR in their preliminary report on the EX V6 which was recently released on their website, has only good things to say about it.
  • blufz1blufz1 Member Posts: 2,045
    Honda is very good at standing behind their products. So if something is really wrong with the VCM, I would be hopeful they would fix it for free even outside the warranty period.
  • elroy5elroy5 Member Posts: 3,735
    I thought my post might be taken the wrong way. Oh well. :sick:
  • golfrskigolfrski Member Posts: 262
    That said, I'm sure it can be felt a bit (like transmission shift can be, especially with colder weather).

    It can be felt ALOT. its ridiculous and my prediction is MANY more unsatisfied V6 owners will come forward. The vibration is very noticable and the surging is uncomfortable. Having a "clue" comes from experienceing the issue that others and myself are feeling. Your lucky that you have not had this issue,thats great. but the new engine has issues,, plain and simple and people need to be aware before they buy.
  • golfrskigolfrski Member Posts: 262
    agree... just looking for rmore feedback/user experiences from different forum users. Honda is looking at it today. I will keep everyone posted.
  • golfrskigolfrski Member Posts: 262
    Thanks Pat. :-( yes indeed I am distressed as would anyone spending such a great deal of money. and I appreciate this forum to discuss the issue and continue the dialog. I am let-down. Honda should have done more testing and homework here on this new config. It is becoming painfully obvious that I am not alone and as the cars begin to hit the streets in greater numbers, the issues, posts and concerns are mounting.. I am hopful Honda reads these as well. I will ceratinly point them to this and all the other forums for customer data. As the service manager at my dealer said, "the car is so new that they havent seen many reports yet".." "they expect this to become a more widespread concern", and that was a comment from a Honda Service Manager!
  • golfrskigolfrski Member Posts: 262
    I agree Hpowders that is what is so puzzling to me. Surely all the prof reviews would have made comment. Although as I said I am starting to see other posters that are seeing the same thing.. maybe its point of origin or something related to that... well we'll see and I will let you know. I am test driving some others today.

    Thanks for the kind words.....
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