Acura MDX SUV Forums banner

1 - 16 of 16 Posts

·
Registered
Joined
·
414 Posts
Discussion Starter #1
I found this on the other site, which I find particularly interesting as I had that 'fluttering' thing happening on my 2014. I did a 3x drain an flush myself and it really didn't appear to help (have yet to have the dealer do the software update, but others have said it didn't really help either).

Someone on here had the dealer check his engine mounts and they may be another reason for the vibration/fluttering, however, the dealer was planning on replacing the engine mounts, not updating any software.

Now the thing that made me go 'hmmmmm', is that we had a warm spell here last week or so with temps above 10 celsius at least and I didn't notice any fluttering. Then temps went back to below 0 celsius and I noticed the fluttering again.

As far as I can tell, this TSB 14-078 is for the Pilot, but do we not have the same tranny and VCM system in the MDX?

"“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
 

·
Registered
Joined
·
869 Posts
2nd generation Pilot has 5-speed AT and a previous multi-port fuel injected 3.5L V6, not the direct injected 3.5L V6 found in all 3rd-gen MDXs. So neither the transmission nor the engine are the same as 2014+ 3rd-gen MDX. But both versions of the 3.5L V6 engine have VCM.

My 2014's vibration is much worse in the cold, so I'm thinking engine mounts.
 

·
Registered
Joined
·
414 Posts
Discussion Starter #4
2nd generation Pilot has 5-speed AT and a previous multi-port fuel injected 3.5L V6, not the direct injected 3.5L V6 found in all 3rd-gen MDXs. So neither the transmission nor the engine are the same as 2014+ 3rd-gen MDX. But both versions of the 3.5L V6 engine have VCM.

My 2014's vibration is much worse in the cold, so I'm thinking engine mounts.
Mine is worse in the cold as well. Why would the cold affect engine mounts?
 

·
Registered
Joined
·
146 Posts
Mine is worse in the cold as well. Why would the cold affect engine mounts?
Same here. My MDX seem to drive better if temps are above 35F ish, when below 30F, VCM vibrations are back(mild but noticeable) even after engine mount replaced.

Also noticed couple of things when it is too cold...
1. MDX was noticeably sluggish (drive & acceleration)
2. Not sure why brake pedal was very hard(when MDX was left in cold) until I start the car.
 

·
Registered
Joined
·
869 Posts
Rubber gets harder in the cold, and transmits more vibration. But our 3rd-gen MDXs don't have solid rubber engine mounts, so the issue may be that the "active" component is no longer working and all that's left is the "passive" rubber.
@neoshi, that TSB was cited above, but it's for 2nd-gen Pilot (2012-2015) and AFAIK that vehicle doesn't have the same type of engine mounts as 3rd-gen MDX/Pilot. They are hydraulic mounts, but not the "counter-vibrating" "ACM" kind. Not clear if the driveshaft isolator could be relevant, but I'm not aware of a TSB that cites that in 3rd-gen MDX. VCM and/or torque converter could certainly be involved.
 

·
Registered
Joined
·
2,793 Posts
Rubber gets harder in the cold, and transmits more vibration. But our 3rd-gen MDXs don't have solid rubber engine mounts, so the issue may be that the "active" component is no longer working and all that's left is the "passive" rubber.

@neoshi, that TSB was cited above, but it's for 2nd-gen Pilot (2012-2015) and AFAIK that vehicle doesn't have the same type of engine mounts as 3rd-gen MDX/Pilot. They are hydraulic mounts, but not the "counter-vibrating" "ACM" kind. Not clear if the driveshaft isolator could be relevant, but I'm not aware of a TSB that cites that in 3rd-gen MDX. VCM and/or torque converter could certainly be involved.
Yeah i know i was posting it because he mentioned it and quoted something without context

Sent from my Pixel using Tapatalk
 

·
Registered
Joined
·
414 Posts
Discussion Starter #9
Yeah i know i was posting it because he mentioned it and quoted something without context

Sent from my Pixel using Tapatalk
Without context? I specifically mentioned that the TSB was for the Pilot. How much more context does one need?
 

·
Registered
Joined
·
2,793 Posts
Without context? I specifically mentioned that the TSB was for the Pilot. How much more context does one need?
Well, without full context. It's just always good to actually see the whole tsb whenever these are mentioned. Although you mentioned the pilot, you didn't mention what generation. One could wrongly assume you were pointing to the current pilots that are based off our mdx, but in fact the tsb applies to an older generation.

I do admit though that i see that path you're leading us to. In many ways the Honda engineers just adapt the same old mechanical systems to a different frame and chassis with each generation, so there's a good chance the old problems are still happening. We just need to be cognizant of the fact that we have somewhere different powertrains.

Sent from my Pixel using Tapatalk
 

·
Registered
Joined
·
2,793 Posts
by chance is this the transmission judder issue?
Probably not if he did 3x drain and refill. Or the problem got so bad after so long that it really did damage the torque converter. But still, the tach should bounce.

Sent from my Pixel using Tapatalk
 

·
Registered
Joined
·
414 Posts
Discussion Starter #12
by chance is this the transmission judder issue?
Probably not if he did 3x drain and refill. Or the problem got so bad after so long that it really did damage the torque converter. But still, the tach should bounce.

Sent from my Pixel using Tapatalk
No tach bounce and I did the 3x drain / refill and still the judder but only (it seems) in below 0 Celsius weather. According to the TSB (the Acura TSB, not the Honda Pilot TSB), even with the judder it is not 'supposed' to damage the torque converter.

I do have to get a dealer to do the reprogramming - maybe that will help. I'm leaving the car this Thursday to get the programming done. The 3x flush didn't make any difference. If the programming doesn't help either, then I'm leaning toward engine mounts or 'maybe' the driveshaft thingy mentioned in the Honda Pilot TSB, since, as mentioned, I only seem to get the judder in colder temps.
 

·
Registered
Joined
·
2,793 Posts
Well, he can get it, but just has to pay for the job. Just make sure that the hours match the labor hours shown on the TSB.
 

·
Registered
Joined
·
414 Posts
Discussion Starter #15
Well, he can get it, but just has to pay for the job. Just make sure that the hours match the labor hours shown on the TSB.
Yes, I'm out of warranty. I'll have to make sure the hours match only for the programming, since I did the 3x fluid change myself.
 

·
Registered
Joined
·
414 Posts
Discussion Starter #16
So, I had the dealer do the software update sometime since the original post (maybe March this year) and the juddering seemed to lessen, however, it may have been just the warmer weather returning. I mention this because it's now cold again and the judder is back, though definitely less pronounced.

However, it's been just over 24 000 KM since my 3x drain and fill, so maybe the fluid is worn or whatever Acura claims happens to the fluid (wearing out faster than expected or something). I'm right in the middle now of doing a 1x drain an fill because I had 3 bottles of ATF DW1 laying about (it's draining while I type).

This got me to thinking - I'm not sure what the DW1 is composed of, but a friend suggested that DW1 may be Group III base oil and perhaps is too thick when cold. Switching to something like Red Line D6 (PAO or Ester/PAO base) might have better flow in the cold weather and alleviate the shudder. I know that in my 05 TSX (which originally was Z1 but had been filled with DW1 as Z1 was phased out) when I did a 3x flush and fill to replace the DW1 with Red Line D4, a very common tranny whine on that generation of TSX changed in pitch and moved from occuring at 120 km/h to 130 km/h. So the thicker fluid definitely made some change in the TSX.

Anyway, that's my plan and I'll update when my 3x flush and fill with Red Line D6 is complete. Unless, of course, my 1x flush and fill with the DW1 does away with the shudder, in which case, I'll change my tranny fluid 1x every 20 to 24 k KM.
 
1 - 16 of 16 Posts
Top