jcrespo7908

I am truly dissappointed with the lousy rear suspension on my 2015 MDX. This SUV is supposed to stand next to the Q7, X5 & RX350 but its far from it. I returned an RX350 lease to get into this third row seater but only to be discontent with the rattling sounds going on in the rear. I only have 2000k and it sounds like a city cab whose suspension is shot. I've taken it to Acura but they say nothing is wrong. I took a test drive on a new one and it also sounds horrible. I was too excited to notice when I test drove it. Now I'm stuck with a 3yr lease. I hope they figure out what is causing all that racket back there.

mgalbr22

See my posts on same defect in the RLX. No resolution.
I also observed the same thing in the loaner mdx I had last week.

RDX FAN

If it is rattling something is wrong. How can Acura keep blowing owners off when there is a defect. Are all Acura techs deaf?

Maybe if 5 or 6 or more Dissatisfied owners show up at the service department at the same time the dealership will listen.

If this defect is not fixed, all Acura owners will suffer at resale time when these vehicles get a bad reputation.

JADS

We have had our 2015 MDX for about 2 months now and also have excessive noise from the rear end. There seems to be two issues. One is an occasional "thunk" going over a bump that sounds like something is hitting, like the exhaust system hitting the frame. The other problem is more of a hollow echo sound. There seems to be a resonant box somewhere in the back end. I notice it most going 30 to 45 miles per hour. At highway speeds it is very quiet. I got some relief by putting a towel underneath the rear tray. The bottom of the well, just above the spare tire, can pick up the vibration and magnify it just like the box on a guitar. This helps some but doesn't resolve the problem. I had it into the dealer and the service technician acknowledged the problem but said he hears it on all the new MDX's so they couldn't find an issue. Seems like a design flaw and Acura needs to figure out how to fix it. I am taking the sales manager for a drive in it on Tuesday so he can hear it first hand. This is our first "luxury" car and so far I am not impressed. Some of the features of the car are great. Steering is really good, the headlights are incredibly bright and the noise on the highway is really low. Seating is very comfortable. I'm hoping Acura can fix this because I would love to be thrilled with this car.

tman

You brought up "resonating" noise. I had a similar issue where the noise comes on at 1600rpm? Look at your tach when you hear the noise. I had a '14 MDX loaner, and it does a similar noise but it was barely audible at 1600rpm. Mine was much louder at the same rpm. Tech rode with me and verified the noise. They drove 2 other "15 MDX's and noticed the same noise at 1600rpm, but much quieter. Part of the Active Noise Cancellation. Ended up I had a defective ANC control unit. See below link if it applies to you.

https://acurazine.com/forums/3g-mdx-...terior-923777/

JADS

I have not noticed the rpm link. The resonating that I am talking about is when the rear end goes over a bump. I hear a hollow sound that sounds like it is resonating at a certain frequency. I don't get it when I am at highway speeds.
I was looking underneath the car today trying to see if I could find anything. I wonder if it could be coming from the fiber wheel well covers behind the wheels. When I tap on them they have about the right sound, maybe they are vibrating.

tman

My noise was occurring when I would be going at a steady speed like 40mph on level road and tach reaches 1600 and I would get a resonating noise. Guess your issue is different. Did you see new TSB regarding rattle in back?

http://www.urvi.net/forumfiles/SB/B15-009.PDF

EE4Life

Acura has had some issues with parking brake rattle on 2014 and 2015 MDXs when driving on rough roads or going over bumps. This rattle can be mistaken for a rear suspension noise.

During assembly, the cable was being adjusted too loose, causing it to rattle when driving. This problem has since been addressed.

In other instances, they found that the cable was adjusted too tight. This causes the parking brake shoes to lift off the anchor block and rattle while driving. The best way to avoid this rattle is to make sure the parking brake cable is adjusted to spec.

This information comes from Acura Tech2Tech video "Parking Brake Rattle in 2014-2015 MDX" from February 2015.
http://techinfo.honda.com/rjanisis/p...=bmv150203.flv
http://tor.in.honda.com/rjanisis/pub...=bmv150203.flv

tman

Thanks. This should be posted in the TSB section too.

EE4Life

I disagree, as it is not a TSB.

tman

Doh! You are right. Should be put somewhere as a sticky under "Problems and fixes."

cbauer1321

This is the only thing about the MDX that I dislike. I had a 460 Lexus before this so the noise is even more irritating. If I trade out of it this will be the No. 1 reason. The dealers have told me there is nothing wrong normal noise. I hope Acura fixes it because everything else about it I love.

JustPlaneChris

I posted this at MDXers.org, but thought I'd share here for those who do not frequent that forum.

Going on the theory that the rear cargo box was acting as a resonator for road and suspension noises. I ordered and received sound deadening material. I ended up getting Reckhorn ABX (from Amazon) after doing some reading in some of the stereo forums.


As a start, I just put some on the outside of the cargo box. And guess what?

It freaking WORKED!

If I feel energetic I may remove carpet and interior panels and do more, but for now I'm well pleased by how just putting some on the back of the cargo box hushed it up. The only drawback is that the box is fuzzy, so the stuff doesn't stick very well. It won't go anywhere with the box in place of course, but it will probably fall off if you remove the box to get to the jack. Some 3M contact cement spray fixes that issue.

Chris

tman

How about a photo of what you did?

JustPlaneChris

Odd, when I did the original post it wouldn't let me attach files (or edit). Now it will, so I guess I hit my magic post number.

As I pointed out in the other forum, my wife doesn't think it sounds any different, but I do. And since I was the one being driven crazy by the thumps, that's all that matters, right?

Chris

JustPlaneChris

As a follow-up, today is about 40 degrees colder than yesterday, and the thumping is back to its former loud self. I suppose whatever is making the noise is temperature-sensitive, so I suppose my "fix" was just coincidence. <sigh>

Now I just need to decide if it's worth another visit at the dealership to see if they can figure out what makes the noise, or just accept that it's "normal" and try to ignore it.

Chris

RDX FAN

Accepting it as 'normal' is what Acura would like..... A noise like you describe is definitely not right.

mgalbr22

What you are going through, in terms of the clunk/rattle and the repsonse of the dealer and acura, is the same thing RLX owners have dealt with for over a year.
They released a tsb for new front struts that apparently helped some but not others and, of course, did nothing for the rear end clunk.
Do not accept the statements that this is "normal" or "characteristic of the vehicle". If every time you put the car in drive it went into reverse instead, as long as this occured with every mdx, one could say this is characteristic of the vehicle. Would that make it an acceptable defect? Same faulty bs logic.

JustPlaneChris

Yeah, and it's getting louder, or maybe I'm just focusing on it more. At any rate, as soon as I have some time to spare I'm taking it back (again) and they can keep it until they fix it. It is unforgivable that the suspension makes more noise, on the same streets, than my 1998 Mazda pickup truck!

Chris

conelectric

Its been a while since I had the rear struts changed and 900 miles. I feel that "thunk" noise at low speeds is much diminished if not gone. That noise I felt was assymetrical, on the drivers side. The rear noise at slow speeds in potholes is there but is better. Im happier so that's good.
Now after my first big trip to Vermont, I was very happy on the highway, very quiet and handled very well on snow. I now have 3000 miles on my 2015 MDX ( and my first ticket- 37 in a 25 mph zone!!)

mgalbr22

Amen!
I asked the dealer months ago to keep my rlx and give me a loaner until they had the parts from Acura to fix it.
No way.

mgalbr22

Will be interesting to see whether acura scraps the mdx suspension design the way they have for the 2016 RLX.

Additional Enhancements for 2016 RLX
To improve overall ride and handling quality and reduce noise, vibration and harshness (NVH), the chassis of the 2016 RLX has received multiple tuning refinements. Both the front and rear shock absorbers get an increase in piston rod diameter and the rear stabilizer bar's stiffness is decreased. The front and rear spring rates and shock absorber damping force were all decreased to provide better shock absorption and road surface tracking. Furthermore, the front upper spring/shock mounts and rear bump stops were changed for improved action.

cbauer1321

I agree 100%, it sounds like a $300 beater on rough roads. Definitely not a highline quality ride on rough roads.

JustPlaneChris

Just to update this group, my MDX is back in the shop. They did hear the thumps and agreed it wasn't normal. Both rear shocks are being replaced, it should be ready today or tomorrow. I will report back as to whether it actually fixes it or not.

I'm doubtful, for a couple of reasons:

1. They said they drove mine back to back with a new one and they heard "some noise" from the new one, but mine was "much worse". That tells me the shocks are all crap, to one degree or another, and Acura has no fix.

2. There is hardly any sound-proofing insulation back there! Look at these photos from a stereo installation shop, and note that the area where the shock attaches is just bare metal under the interior panel! If ever there was a place for some Dynamat or similar product, that's it.

https://www.facebook.com/media/set/?...8139066&type=1

Chris

JustPlaneChris

Got the MDX back today, and did some driving around. The temperature is a bit warmer today than when I dropped it off, but it does seem somewhat quieter. Oddly, the video sounds much the same. I guess that's just a trick of the camera:


There is a seat-of-the-pants difference too, I feel a lot less of the thump in the butt when the back end of the car goes over the rough spot, so I do believe there was something wrong with the shocks.

According to the invoice they replaced both, part number 52611-TZ6-A01. This is not a new part number, online shops show it is the same one that fits 2014 and 2015 models.

I expect that within a few thousand miles it'll be sounding just like it did before, but if that's the case they can just keep replacing them till they get sick of seeing me.

Chris

mgalbr22

You're right based on the video, it seems there is little change. However, I see why you think it is an improvement, but guessing you'd say it is unacceptable, correct?
My assumption is that the design and/or application of the amplitude-reactive dampers is defective. What you are observing is some part-to-part variation since there is no change in the number or suffix. Presumably, indicates an undocumented change in the design,material or assy process. Alternatively, could be attributable to a process that is out of control.

JustPlaneChris

Yeah, the video (audio) doesn't really hear much of the change. What is different is that the sharp "rebound thump" over small bumps is gone, now you just hear the tire thudding. It's still louder than I think it should be, but it is now down to the same level as every other MDX, so of course Acura says "fixed".

I believe it will be up to us as owners to add additional sound proofing if we want it to be any quieter, I doubt Acura will ever do anything about it.

Chris

JustPlaneChris

So here's something interesting... while looking at Acura's site today to find the email address to which to send a nice letter about my experiences, I ran across some FAQs. Tell me if this sounds familiar:

Why does my 2014-15 RLX make a clunk or rattle sound when going over bumps?
Some Acura RLX owners have reported hearing “Clunking” or “Rattling” noises from the front or rear of their vehicle when traveling over abrupt changes in road surfaces.
Please click here for a descriptive video.

I'd love to link directly to the video, but I can't seem to do it. You'll have to go to Frequently Asked Questions | FAQ | Acura Owners Site and scroll to the bottom to see it. Needless to say, the problem and sounds described in the video are exactly what us MDX owners are experiencing too.

And guess what? The RLX is also equipped with "Amplitude Reactive Dampers". Sound familiar? Looks like Acura is just spreading around the crappy parts. <sigh>

Maybe some year us schmuck owners will get some quiet shocks.

Chris

mgalbr22

Precisely.
See my post no. 22 above re redesign of 2016 RLX suspension.

JustPlaneChris

So.... if they follow that trend, there will be a mid-cycle refresh of the MDX suspension, and existing owners will just be told "oh, sorry... It's functioning as designed."

Chris

Sam Axe

The TLX uses the Amplitude Reactive Dampers as well but have not seen this type of complaint over there. Is this strictly a MDX/RLX problem? It's interesting that new MDXs off the lot have some degree of the thumping noise over bumpy pavement but less than if the vehicle has some miles on it.
Chris- Hopefully the damper replacement holds up. It's difficult to tell on the video but it still sounds louder than it should be, and how can they get the front dampers right and not the rears? Good thought about the sound dampening, though if the shocks were engineered correctly that probably would not be necessary. The MDX is not a mass market vehicle however it is possible that Acura is sourcing the dampers from more than one supplier though they would all be under a single part number. That could explain why some owners have the complaint and some don't.

JustPlaneChris

I had a TLX loaner during one of my service visits and it definitely wasn't thumpy over the very same roads you saw in the video. It was VERY quiet, and honestly a pretty nice car. Too bad my back doesn't like getting in and out of low cars any more.

Chris

weather

The RDX have some of these reactive dampers and ours was horrible...so much so that it was one of the factors we got rid of it.

We swapped our RDX for the ILX which also has reactive dampers and while the problem is present, it is somewhat muted because it has a regular trunk rather than the open cargo of the RDX. Had we not been offered a smokin' deal on the ILX, the g/f would have gotten something else but the lease was the same (20$ difference) than a base Civic so it was a no brainer.

I was concerned to see whether the TLX was going to have the same problem since the RLX, RDX, MDX and ILX have the same issues, especially in colder climate, but it doesn't appear to be the case....which I am pleased but to an extent, surprised. That isn't to say that the TLX isn't having some of its own challenges.

Suffice to say, I'll take a little cooling break from Acura for my next toy and see if things improve in about 3 years. We'll still have our ILX but I am interested to see how our IS350 F sport will treat us....Time will tell I guess.

If Acura reads these forum, which I hope they do, I hope they realize that taking forever to address customer's concerns is not what will maintain their once excellent record for quality and reliability. While the reliability is still there, their initial quality seems to be taking a slight regression, and as such, may have cost them a loyal customer.

JustPlaneChris

Mine is still behaving better after getting the rear shocks replaced, but it's still louder than my 2010 Jetta Sportwagen was on the same roads, which is ridiculous.

And on the "bad news" front, after a week of research, the Acura client relations guy called me back to say that Acura is not currently working on any sort of fix for this noise. So they apparently consider it "normal" and won't be doing anything to fix it.

They even went so far as to say my plan of adding dynamat wasn't going to help, because "the sound is being transmitted through the body structure".

I was polite, but did tell him that the only good thing about this situation was the fact that my correspondence to Acura didn't just go into a bit bucket somewhere and that his actual reply was not satisfactory, because all he basically said was "thanks for sharing your experience".

I also told him I was glad I bought an extended warranty, because replacing shocks every 8000 miles would get expensive otherwise. He was sure I wouldn't need to do that, but my question was "Why would I not? They've already failed once..."

Chris

Sam Axe

I noticed this post in the ILX forum. It doesn't seem a fix would be quick or cheap for Acura. Maybe if the revisions to the rear suspension on the RLX work then those changes spread to the rest of the fleet.

https://acurazine.com/forums/acura-i.../#post15257040

JustPlaneChris

Based on that thread, I think if I decide to do something other than (try to) ignore the sounds, I will have the local stereo shop install Dynamat sound proofing in the rear cargo area, particularly around the shock towers. It'll cost me ~$900, but it might stop me from obsessing about the noise. That's really the only thing I don't like about the MDX! <sigh>

Chris

Calico5888

New 2015 mdx. Harsh stiff ride with associated Thimphu sound from the rear of the cabin. Told dealer and he immediately ordered new shocks and struts for the rear, saying this would eliminate the problem. I can't tell any difference but he has said its all they can do. I want to explore a change in suspension parts from another source to see if I can fix the problem. Has anyone done that with any success? If I can't fix it I'll trade it off....not that I have unlimited funds but I won't live with this thing the way it is. Really disappointing for a $50,000 car.....looks like my first and last Acura.

JustPlaneChris

I have not been able to find any aftermarket shocks or suspension bits for the MDX. If you do, please post here so we all know about it.

Calico5888

I have an appointment with a suspension shop here in Des Moines this week to visit about it. Their expertise is with truck and performance vehicles so don't know if they will be able to help re-tune a factory design like this but want to give it a try. At 74 I'm not prepared to live with it for the next 3-5 years so, if it can't be corrected, I may just take the financial hit and trade it. I feel foolish that I made the purchase without more extensive test driving but just didn't expect something this glaring from a company like Acura. I've driven nearly every other high end SUV and none of them are this rough, jarring and loud. A real design error on Acura's part.

JustPlaneChris

I don't find the ride overly harsh (but I do enjoy a 'sporty' vehicle) but I definitely find the suspension noises to be louder than they should be in an otherwise very quiet vehicle.

I've stopped obsessing about it though, because I'm not willing to take the financial hit and delay retirement because of it!