mrag

There is a new sensation that has been occurring as of late on my 2014 MDX, whereby the VCM action has become more noticeable at select speeds (e.g., 40 mpg). You can feel the VCM “cycling” in and out and/or “settling in” which creates a slight noise and reverberation. The dealer went for a road test and acknowledged exactly what I was experiencing but suggested it is normal. Perhaps – but new to me and my MDX over the past few weeks (wondering if the change to cold weather is a factor, but I do not remember this issue last winter).

So, I did a bit of research on the topic and uncovered a related Technical Service Bulletin issued November 2, 2016 (TSB 16-062/63). The software update was previously done on TSB 16-062, so they followed the course of action for TSB 16-063. No change or improvement. Upon other research - it seems some Honda/Acura products have a torque converter issue. Below is some text I pulled online that speaks to this (albeit perhaps a bit dated info):

“There is a service bulletin by Honda entitled Excessive Vibration Between 30 and 65 MPH (14-078). It is important to note that this bulletin is not addressing a problem with the Active Control Engine mounts. It is addressing the timing of when the VCM is activated and when the torque converter clutch is being applied. The torque converter apply strategy goes from Off, to Partial Apply to Full Apply. With that said, this bulletin addresses excessive vibration between 30 and 65 mph under certain driving conditions. It sites possible causes for both 2WD and 4WD applications as a calibration VCM operation combined with the action of the lock up torque converter causing excessive vibration. With 4WD vehicles, the propeller shafts center support bearing bushing material may not effectively dampen vibrations in cold (below 32°F) temperatures. The corrective measures are to perform the inspections provided in the bulletin. Based on the results, a PCM program update may be needed to correct the conditions. For 4WD vehicles, the propeller shaft may also need to be replaced.”

Has anyone else experienced this or a similar issue on an AWD MDX? If so, please share as I would like to report back to the dealer other avenues to explore for a solution.

kuzdu

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https://acurazine.com/forums/fifth-g...uzzler-951929/

TLbullet

I believe i experienced same issue with my 14' awd. I Only experienced it while maintaining highway speeds. I had Acura look at it, and you guessed it, they said it was normal. They said it was one of the valves shutting off. I would have preferred to waste gas and keep valve on! Was horrible. I now have 17' awd, havnt experienced it with this 9 speed tranny.

mrag

This problem is growing more pronounced and I am even getting a light groaning if coasting around 30 MPG and increase speed from there. Thought maybe now that we are in winter weather the colder temperature may have something to do with it - but doubtful, this has been a problematic vehicle for much too long now.

Anyone having similar issues or can offer any ideas as to a fix?

tman

Is this occurring at around 40mph at 1600rpm? I get a reverberation at that speed and rpm. For me its the Active Noise Cancellation working. I don't like the thing, and will disconnect it once weather warms up. Basically the car creates the reverb through subwoofer.
When my 15 mdx was new, it was overly loud. When brought to the dealer , they went through a diagnostic routine including forcing the torque converter to vibrate. They had a hell of a time figuring it out. They had to call their helpline and they figured out it was the ANC system. They changed out the microphone, that did not fix it. So they changed out the ANC module and that fixed it. I had a mdx loaner during that repair and sure enough, the same reverberation was heard, but at a much more reduced volume. Not sure if this is your issue, but when you said "reverberation" that is what I was going thru.

mrag

Thanks - definitely something to look into. I seem to feel it in the accelerator pedal (slightly) with a sensation like the VCM is cycling on/off. Wonder what would cause the ANC to change as the vehicle ages to cause this experience? I was assuming it might be tied to engine balance when cutting fuel to run on fewer cylinders. Simply did not occur to me it could be sound only.

Was yours fixed to your satisfaction?

tman

Yes it was fixed to my satisfaction, although I still can hear it. Never felt it in the accel pedal. When it was loud, I became so sensitive to it, that I don't like it even when its quieter. The volume is the same as the loaner mdx, so I guess that is normal. Some owners notice it and some don't. Wish I was one of the DON'T notice it.

korbo

I had this noise after I picked up my off-lease 2014 MDX. I brought it in 3x's before they could duplicate the noise. After the technician heard the sound, he told me now he could order the plastic mounting pins THAT WERE MISSING from the wind/noise surround under the hood. After they replaced (4) of them that were missing, I still got the sound. I opened up the hood, and the tab that connects the front piece to the drivers side piece was NOT CONNECTED.......after I 'connected' them, I have not heard the sound since. Some other guys have placed foam pieced under this tab...Mine doesn't have any on it.

9SpeedTran

So after I had my '15 TLX transmission replace, I got excessive vibration whenever the VCM kicked in. What was required to fix this problem was for the Active Control Engine mounts to be resynchronized while the engine was in gear. The lead mechanic at my dealer spent a good amount of time with Techline straightening this out, and now VCM is unnoticeable when it kicks in or shuts off.