A8L 2011-2014 D4 Front strut "humming/harmonics" claimed by Audi to be Tire noise
11-29-2015, 01:35 PM
#121
AudiWorld Member
The problem most face is the type of road that is being driven and tire noise harmonics.
I have driven certain roads that were either milled or ground and only get a harmonic noise on these certain roads. It's usually a ground concrete road, or a milled asphalt surface. Get on a smooth paved asphalt road and noise gone.
Anything will vibrate like a tuning fork with the right frequency and that is what is happening in this instance.
Think of a ground and/or milled surface like a vinyl record. It is made of up of small bumps unseen by the naked eye just like the record is, when the tires run over these small ripples and micro bumps it introduces a vibration and harmonic into the tires and wheels. Different wheel thickness/weight along with tire weight and construction will vibrate at different levels.
The tires that have the foam inside will cushion and dampen the noise out much like a shock absorber will dampen the suspension.
So for those that drive a ground concrete road or milled asphalt, will need to find a way to dampen the tire noise if they are affected by such roads and can't take the noise.
Seems like the noise cancelling tires are doing what they are supposed to be doing for the many that have tried them.
I have driven certain roads that were either milled or ground and only get a harmonic noise on these certain roads. It's usually a ground concrete road, or a milled asphalt surface. Get on a smooth paved asphalt road and noise gone.
Anything will vibrate like a tuning fork with the right frequency and that is what is happening in this instance.
Think of a ground and/or milled surface like a vinyl record. It is made of up of small bumps unseen by the naked eye just like the record is, when the tires run over these small ripples and micro bumps it introduces a vibration and harmonic into the tires and wheels. Different wheel thickness/weight along with tire weight and construction will vibrate at different levels.
The tires that have the foam inside will cushion and dampen the noise out much like a shock absorber will dampen the suspension.
So for those that drive a ground concrete road or milled asphalt, will need to find a way to dampen the tire noise if they are affected by such roads and can't take the noise.
Seems like the noise cancelling tires are doing what they are supposed to be doing for the many that have tried them.
11-29-2015, 02:44 PM
#122
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This is an old post but if you happen to read, your description is identical to what I hear on my Q7. And yes it has made it a torture to drive rather than the joy it's supposed to be!
So it's a strut issue or wheel bearing? Tried the swapping if tired too and that didn't fix jack!
So it's a strut issue or wheel bearing? Tried the swapping if tired too and that didn't fix jack!
11-29-2015, 03:06 PM
#123
Sorry to hear that Caddy. I love my Audi and yes, on rougher roads I hear more noise, but it was the same issue in my BMWs. If the Lexus doesn't have these issues, then I say you picked the right vehicle for you. and the Lexus is a damn good car! The bad news about Lexus is that you don't get to see your service department very often...
11-29-2015, 05:43 PM
#124
AudiWorld Senior Member
I cured the tyre noise problem. I considered changing tyres and actually ordered some Michelins up which were on back order. Whilst awaiting the new tyres and suffering this horrendous noise in varying degrees. I realised tyres weren't going to cure it, nothing short of a redesign of the car would do that. How did I cure it, simple, swapped back to a Lexus LS600h a fully engineered car in every respect. Now back in luxury motoring as it should be. Quiet, serene, powerful, refined performance, comfort, real quality. The Audi A8 is a joke in many respects in comparison (besides the tyre noise). It is my first and last Audi. Probably my shortest ownership of any car, 4 weeks.
11-29-2015, 08:39 PM
#125
AudiWorld Super User
A Lexus is the most boring car in the world to drive. However, if you don't get any pleasure from the actual driving anyway, then it's perfect. I do agree, though, that that odd vibration I have been living with is one of two spoilers in the car. The telepathic throttle response in sport mode makes it all better for me, though, helped by a confident and stable suspension.
02-18-2016, 11:40 AM
#126
Thanks so much for your post! I'm actually a long time Lexus owner looking at a possible A8 purchase. I was really concerned about reliability and serviceability and the older models don't have a great reputation. Anyway, I wanted to say thanks because the A8 seems like a remarkable vehicle but maybe I'll stick with a 2015 or maybe new. Like you I'm a stickler for a quiet ride and my current LS430 has that in spades. Thanks again.
02-18-2016, 12:54 PM
#127
AudiWorld Super User
Thanks so much for your post! I'm actually a long time Lexus owner looking at a possible A8 purchase. I was really concerned about reliability and serviceability and the older models don't have a great reputation. Anyway, I wanted to say thanks because the A8 seems like a remarkable vehicle but maybe I'll stick with a 2015 or maybe new. Like you I'm a stickler for a quiet ride and my current LS430 has that in spades. Thanks again.
02-18-2016, 01:55 PM
#128
AudiWorld Super User
Derf knows more about it, but apparently the 2015's introduced an updated suspension which included measures to address the vibration. That doesn't help me, but it may be of comfort to you. If you're coming from an LS, you'll certainly find the A8 more engaging, particularly the 4.0 V8 equipped model.
1) Acoustic Dampening: Significant acoustic measures
for improved NVH: Sophisticated acoustic modifications added to the suspension, body & soundproofing materials in the interior.
2) A tuned mass damper – a freely moving mass placed on the front axle – reduces unpleasant vibrations in every version of the new Audi A8.
3)Audi A8L W12: special shock-absorbent tires to further offset any harshness.
4)Enhanced acoustics achieved via soundproofing solutions unique
to a given model or equipment package:
....TDI or rear-seat package: Firewall insulation
....With rear-seat packages: Insulation behind the rear-seat bench
....With rear-seat package: Damper under rear seat
....S8 or rear-seat package: cW-floor covering w/additional damping
....S8: Front carpet w/ improved insulation
And if considering 2015 or newer...A8/S8 Luggage Compartment Design Change:
...improved trunk shape increases the usability of the luggage compartment
Some of the features include:
- Trunk size increases by +1 cu. ft.
- Rear wall inclined by 15°
- Loading floor has been lengthened by 4.2”
- New side trim
- Optimized height of luggage compartment
- Improved space for golf bags
Below pic shows the increased 4.2 inches added to trunk (note where my circa 2011 trunk liner ends in the 2015 trunk)...
.
Last edited by derfA8L; 02-18-2016 at 01:57 PM.
11-25-2016, 05:31 PM
#129
A8 D4 Humming noise issue
Here is a link to the youtube video:
Audi Strut noise - YouTube
It may be a stretch but I believe the my hum and the "whoop" phenomenon may be related and as your strut ages it will get worse... like mine. Now that I think about it when I leave my garage over the first bump it makes the same noise it makes humming and donking down the freeway...
Just out of curiosity why does my comment about the price of the vehicle crack you up? (Besides the fact we all know what these vehicles MSRP'd for...) I could more understand the r&d being limited for a "budget" vehicle however a flagship sedan from a premium manufacturer should not be defective or subject to issues every other car manufacturer can successfully deal with. In my discussion with continental tires, harmonic/vibrational interplay between the car/gearing/tires is taken very seriously and researched/understood on every car. I am not going to give more detail now because I want friends not enemies however I will say I have received information from inside the Audi service department that the struts are what is making the sound. Don't believe me? Find a stretch where the cars hums, then sit in the back seat and be driven down the same stretch... I did. The hum is only generated in the front of the vehicle...
Regarding documenting the event I have... twice now. But how does it help if we can not identify the issue? Audi will give us the same song and dance... If any of you have any suggestions or insight from the youtube link please, please let me know. Thanks!
Audi Strut noise - YouTube
It may be a stretch but I believe the my hum and the "whoop" phenomenon may be related and as your strut ages it will get worse... like mine. Now that I think about it when I leave my garage over the first bump it makes the same noise it makes humming and donking down the freeway...
Just out of curiosity why does my comment about the price of the vehicle crack you up? (Besides the fact we all know what these vehicles MSRP'd for...) I could more understand the r&d being limited for a "budget" vehicle however a flagship sedan from a premium manufacturer should not be defective or subject to issues every other car manufacturer can successfully deal with. In my discussion with continental tires, harmonic/vibrational interplay between the car/gearing/tires is taken very seriously and researched/understood on every car. I am not going to give more detail now because I want friends not enemies however I will say I have received information from inside the Audi service department that the struts are what is making the sound. Don't believe me? Find a stretch where the cars hums, then sit in the back seat and be driven down the same stretch... I did. The hum is only generated in the front of the vehicle...
Regarding documenting the event I have... twice now. But how does it help if we can not identify the issue? Audi will give us the same song and dance... If any of you have any suggestions or insight from the youtube link please, please let me know. Thanks!
Hi, this is the same problem I'm having with my A8 2013. I bought this Car 3 months ago and the noise is still the same after I've done 8000 miles, I was thinking to get struts replacment but I don't if you've solved the issue, would you kindley let me know if you have? Thanks
11-25-2016, 09:23 PM
#130
AudiWorld Super User
Audi addressed the suspension vibration and harmonics issue in 2015 by:
1) Acoustic Dampening: Significant acoustic measures
for improved NVH: Sophisticated acoustic modifications added to the suspension, body & soundproofing materials in the interior.
2) A tuned mass damper – a freely moving mass placed on the front axle – reduces unpleasant vibrations in every version of the new Audi A8.
3)Audi A8L W12: special shock-absorbent tires to further offset any harshness.
4)Enhanced acoustics achieved via soundproofing solutions unique
to a given model or equipment package:
....TDI or rear-seat package: Firewall insulation
....With rear-seat packages: Insulation behind the rear-seat bench
....With rear-seat package: Damper under rear seat
....S8 or rear-seat package: cW-floor covering w/additional damping
....S8: Front carpet w/ improved insulation
And if considering 2015 or newer...A8/S8 Luggage Compartment Design Change:
...improved trunk shape increases the usability of the luggage compartment
Some of the features include:
- Trunk size increases by +1 cu. ft.
- Rear wall inclined by 15°
- Loading floor has been lengthened by 4.2”
- New side trim
- Optimized height of luggage compartment
- Improved space for golf bags
Below pic shows the increased 4.2 inches added to trunk (note where my circa 2011 trunk liner ends in the 2015 trunk)...
.
1) Acoustic Dampening: Significant acoustic measures
for improved NVH: Sophisticated acoustic modifications added to the suspension, body & soundproofing materials in the interior.
2) A tuned mass damper – a freely moving mass placed on the front axle – reduces unpleasant vibrations in every version of the new Audi A8.
3)Audi A8L W12: special shock-absorbent tires to further offset any harshness.
4)Enhanced acoustics achieved via soundproofing solutions unique
to a given model or equipment package:
....TDI or rear-seat package: Firewall insulation
....With rear-seat packages: Insulation behind the rear-seat bench
....With rear-seat package: Damper under rear seat
....S8 or rear-seat package: cW-floor covering w/additional damping
....S8: Front carpet w/ improved insulation
And if considering 2015 or newer...A8/S8 Luggage Compartment Design Change:
...improved trunk shape increases the usability of the luggage compartment
Some of the features include:
- Trunk size increases by +1 cu. ft.
- Rear wall inclined by 15°
- Loading floor has been lengthened by 4.2”
- New side trim
- Optimized height of luggage compartment
- Improved space for golf bags
Below pic shows the increased 4.2 inches added to trunk (note where my circa 2011 trunk liner ends in the 2015 trunk)...
.
Another that I have spotted on mine (2015), but I thought was standard issue on D4's: There is a large part that looks sort of like a counterweight wrapped in a plastic shell bolted to the front of the front hub area. Looks like some kind of tuned dampener. Might be what is referred to in #2 in the quoted text.
I gotta say, if there is any vibration in these, I sure don't feel it w/ the 2015. It is firm, per the S8 set up, even backed off to the 275/40-20's and now with new Conti DWS 06's on to try for mild winter use. Drove it 200 miles today up through the Sierra's to Tahoe had several hours feel for it at a variety of speeds, driving styles, lots of mountain sweepers of all types and wide variances in pavement quality and material.
Last edited by MP4.2+6.0; 11-25-2016 at 09:29 PM.