mindanalyzer

So a V6 with VCM (disconnecting 3 cylinders and the such)…? I am quite skeptic about this feature. My RDX usually exhibits a very weird behavior which consists of producing a humming (drone, subtle vibration) noise under light acceleration (30-40mph) that bothers me to no end. I have taken it to the dealers (2 different ones) 4 times for this situation and I have always gotten the ‘normal specs’ BS, so I have already given up.

Let me clarify that as a whole I like my RDX (apart from a couple of issues with the rear suspension that the dealer ignored too but I was able to fix by installing a pair of KYB shocks).

Is this “potential problem” a deal breaker? Well, we have to wait but my perspective on the RDX front is that for some owners it is no issue, others feel nothing (or claim so) but honestly for me it is (as I feel it all the time). It pains me to admit it but if I had known about this beforehand, I would have, most likely, chosen another vehicle. As of right now, I know that I have to live with it or trade my RDX, losing a considerable chunk of money in the process which I am not sure I am ready for.

Bear in mind that I am not saying that the 2015 TLX V6 will exhibit the same behavior but when I read Acura V6 VCM, in the same sentence, I can’t help thinking about my RDX noises. I am sure that the TLX will be a great vehicle but I would not take a plunge into a V6 model until I am 120% sure that the humming noise is completely solved.

iforyou

iTrader: (1)

I didn't see/hear/feel your issue with a 2013 Accord V6 which also has VCM.....it's probably just your RDX??

Colin

Noises are hard to diagnose over the internet, but be aware that the RDX is using the 6-4-3 VCM setup. The newer cars (RLX, MDX and TLX) are using a newer setup that is only 6-3.

BEAR-AvHistory

Ignition advance issue - fuel quality? Lots of time weird noise & vibration in light to medium acceleration from a lower speed is a wrong gear for the amount of throttle opening. More prevalent in MT cars.

Could be a few things but a test drive in the TLX should settle the issue for you. Lots of cars are running cyl deactivation with no issues so the TLX should be fine.

mindanalyzer

interesting ... Yes, I read somewhere that the 6-3 setup is much more effective

mindanalyzer

Not really. The second time I complained about this issue, and before it was dismissed as 'normal specs', I was able to test drive another 2013 or 2014 RDX (with 300 miles) and it had exactly the same behavior although just a tad less accentuated

mindanalyzer

Guys, Another clarification. I am just trying to bring this issue up so you are aware that this could be a problem, not that it will be. Hopefully it is not

Detecting this problem during the test drive is near to impossible because the VCM does not start working from the very beginning but it has a learning period (driving habits, conditions, etc)

Stew4HD

I have an Accord Coupe V6 with VCM which I leave on full time (in eco mode). I do not even know when or if the switching occurs. I think it switches because I am getting 31-33 MPG on my 30 mile commute

mindanalyzer

This problem maybe manifests in the RDX because of the combination of V6 w/ VCM (6-4-3 setup as someone mentioned) engine and the [TOO] aggressive mapping of the 6 gears trans [to be fuel efficient and thus competitive]. It could certainly be the case that the gear mapping in your accord is more adequate.
Based on this, the new TLX trans (8 and 9 gears) should be fine as well.

jswift2000

We just traded in a 2012 Honda Pilot with ~44,000 miles on it b/c the engine (VCM 6-4-3) had to be rebuilt due the VCM issue. No way should a car at that age with that few miles (few for a honda ;-) ) need to have an engine rebuilt. However, when the VCM was on, we could never tell. We bought a CPO Acura MDX.

H_CAR

I doubt your Pilot's engine was replaced over a VCM issue specifically. My '11 Odyssey's engine had to be replaced but it was due to manufactures defect. Had nothing to do with VCM.

That was done at 15,000 miles. 40,000 now and the van works as it should.

hadokenuh

I don't think you should be worried too much about the VCM. I virtually cannot detect when it's on or off on my 2014 MDX, even after 15K miles.

jswift2000

The service department didn't pull the plugs. Diagnostic code read P0302 for fouled plug & 77-1 for power train failure, vin was eligible for repair... Traded in the car.

silver3.5

My '12 Odyssey exhibits the same annoying behavior when switching between VCM and regular. Complained to 3 different dealers and all said its a known annoyance from customers but it's normal. My wife can't seem to tell the difference at all! Test drove the '13 and '14 and same thing. Haven't driven the '15 yet! So to me, it would be a deal breaker if it was going to be my daily. Fortunately the minivan is my wife's and all she cares is that it works and gets her from A to B, along with the kids!

TampaRLX-SH

Further differences with the RLX, MDX and TLX VCM V6 engines are all newer Earth Dream Direct Injection engines. The RDX is likely to get an Earth Dreams DI engine in the MMC.

The DI engines may manage VCM along with the 6-3 logic.

jshaw

If it really matters, switch to sport+ on every startup. It disables VCM.

a77

so often this low speed drumming is due to overly ambitious gearing - lugging along at too low revs in a dubious attempt to get better mileage - which may work on epa tests but not in real world. It's why I will not buy an auto ever without some degree of manual override. Many Hondas do this, The last gen CRV was a classic case. Though has to be said most people don't notice it. VCM may make the issue worse though only in the old Accord Hybrid was VCM operation obvious. The ECON button has nothing to do with VCM by the way. Nor does the ECO light - that just comes kn whe. The car is getting better mileage than a certain threshold, usually 10 litres per 100 kms. The 6-4-3 system was brought in to reduce premature wear on the active engine mounts VCM engines have. The mounts were improved enabling a return to the 6-3 system which can also spend more time in 3 cyl mode as the in the Accord at least it has a 3 phase cam - it's a true VTEC engine with more low speed torque than the J35 in the 8 gen auto. DI helps further of course.

Mike_TX

I had a 2014 RDX, and the only thing I ever noticed was a very slight change in engine harmonics when it went to 3 cylinders - and that happened at highway speeds. Otherwise it was a nice drive, especially in town.

My RLX has the newer 6-3 setup, and I absolutely cannot tell any difference at all when it drops 3 cylinders. None. Nada. Zilcho.

I figure the TLX will perform the same as the RLX. That said, though, I'm kind of glad I'll be waiting until the 2016 TLX debuts to consider another trade. That should give them time to get the bugs (if any) out of both the VCM AND the 9-spd tranny.

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iforyou

iTrader: (1)

and possibly a Type S

One4AL

I wish I would have read your post 5 years ago (back in July 2014). Mindanalyser you were right when assuming the VCM would be an issue on the 2015 TLX. It happens to also be an issue on 2016, 2017, 2018, 2019,...and it keeps on going since Honda/Acura claims this is a 'Caracteristic of the vehicule'. For more information on this 'caracteristic', just look under Vibration and/or VCM and you'll find many more comments.

Good job Mindanalyser! Very kind of you. You are gifted with collective wellness and awareness. It's not everyone who's willing to spend his precious time to advise folks (he doesn't even know) about a potential situation that could become a game changer for them. Would you have been graciously offered the same "heads up" prior to purchasing your RDX, you would certainly have reconsidered your decision. For all upcoming potential TLX V6 buyers, Thank you for being the TLX Nostradamus.

Hink714

• I am exI am experiencing the very same problem with my 2015 Acura TLX. I am overall very pleased with the car. One exception being the highly annoying VCM that seems to kick in and out even on a regular city street causing quite a noticeable vibration to the point that it feels like a car malfunction. The dealer has assured me this is normal and his attempt to mitigate with no real resolveperiencing the very same problem with my 2015 Acura TLX. I am overall very pleased with the car. One exception being the highly annoying VCM that seems to kick in and out even on a regular city street causing quite a noticeable vibration to the point that it feels like a car malfunction. The dealer has assured me this is normal and his attempt to mitigate with no real resolve

gptlxdrvr

Get a VCM muzzler. Cheap and easy fix