Reporting back: Quattro Rumble still there...

[Spitfire007]

So i just had the front and center differential fluids, as well as transmission fluid/filter replaced today. They also did an adaptation on the Trans.

So far, the car feels the same as before. Rumble/vibration on sharp 90 deg. turns in town.
Trans feels a little better/smoother, maybe less hesitation, will see when it's cold.

They did say the rumble is still there, that sometimes it takes two differential services to make it go away....for some odd reason.

This is at a very competent Indy that specializes in our pricey Euro cars....it's a shop that really works on cars, in a grimey and old school garage, not some boutique super spa for your car. These guys get their hands dirty.

Here's hoping it either goes away on its own, or that a second fluid change after 500-1000 miles or so will help.

I do have worn front lower control arms, and the passenger side motor mount leaked all fluid.....maybe these are contributing factors?


Will report more as I get to it.

[A665]

Very difficult to believe that the issue you describe is caused by poor diff and/or trans fluids. Even more difficult to believe that changing the fluids twice is even considered a likely fix.
The worn control arms seem a more likely cause to me. But don't take my word for it, as I'm no mechanic.

[JWebb_C7_Comp]

Very difficult to believe that the issue you describe is caused by poor diff and/or trans fluids. Even more difficult to believe that changing the fluids twice is even considered a likely fix.
The worn control arms seem a more likely cause to me. But don't take my word for it, as I'm no mechanic.

I'm not a mechanic. But, I've had the transfer case "fluid" changed on both my A6 and my wife's Q7. That plus switching to our winter wheels/tiers (on each vehicle) I simply don't feel the "rumble" on either vehicle. We've had a handful of BMW's (a few AWD) and never felt that once. That said, it seems to me the AWD in Audi is more sensitive and precise. Have you considered uneven tire wear F'ing with the computer??

Rolling on winter wheels, with fluids changed, I don't feel anything.

FWIW i think the rear Diff on the Q7 was changed along with the transferase (middle diff). I've done neither on the (front or rear) on the A6, but it just rolled 50K today. Given that, i'll do both chambers of the rear sport diff and front diff before winter's end.

On my wife's Q, either or both front and read diffs will be done with next oil change (if neither has been done). That is the main family vehicle and is a great drive all the time, even in states where you can hit high digits frequently for a long time.

[Spitfire007]

I have looked into everything.
Car is a well kept 2016, 78xxx miles.
Noise and vibes started very lightly 1.5 years ago. Tires haven't changed anything, and it has 6 month old Michelin AS4s on it.
It's getting worse and worse but very slowly. No wear, no leaks. Nothing unusual to see besides control arms that have leaked fluid (no clunks or squeaks though) and a passenger side motor mount that needs to be changed.

Maybe it's the sum total of those two slightly worn components...


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[Spitfire007]

So, when turning 90 degs, at parking lot speeds or higher, under very light or heavy throttle, the center of the car vibrates.
If I pop it into neutral, the vibes go away immediately.

Any other insight from anyone?


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[zyrofillica]

So, when turning 90 degs, at parking lot speeds or higher, under very light or heavy throttle, the center of the car vibrates.
If I pop it into neutral, the vibes go away immediately.

Any other insight from anyone?


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Did you check your drive shaft rear support? That is a maintenance item. JXB or JHM offers solutions.

[MattyMarkey]

So, when turning 90 degs, at parking lot speeds or higher, under very light or heavy throttle, the center of the car vibrates.
If I pop it into neutral, the vibes go away immediately.

Any other insight from anyone?


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I have had a failed rear Sport Diff; assuming your 2016 has the optional sport diff as well. From the threads I have been a part of for that topic, I have not seen anyone report vibration to be a symptom. Everything else about your statement "turning 90 degs, at parking lot speeds or higher, under very light or heavy throttle" points to the rear diff, since those were the exact driver inputs that let me know mine was bad - I had more of a bad wheel bearing noise.

Fluid changes will not resolve that issue, but there is a rebuild kit - includes seals and a new pump - if you want to try that first. Ultimately, the rebuild kit rarely solves this type of issue.

I personally would rule everything out that you know is wrong with the car - motor mounts and control arms - by replacing them, then go from there.

[Spitfire007]

Thanks for the insight.
I do NOT have the sport diff. In the US I think only the A6 competition got that.

I'll look into the rear diff...wonder why that would go bad at 78k?
Especially on this car...though I had a 2000 Trans Am that ate its diff every 18 months....


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[MattyMarkey]

Thanks for the insight.
I do NOT have the sport diff. In the US I think only the A6 competition got that.

I'll look into the rear diff...wonder why that would go bad at 78k?
Especially on this car...though I had a 2000 Trans Am that ate its diff every 18 months....


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My diff went out with only 11k miles. Still doesn't mean the diff is your issue. I would really rule out anything else currently needing replacement first

[freshjive]

Depending on how severe the vibration is I feel like what you're feeling is the normal quattro rumble. On vehicles with sport differentials the rumble is a lot more pronounced. Typically if it only happens on sharp turns with your steering wheel at full lock I would think that is normal. Once you're at full lock and you put it in neutral it is expected for the rumble to be gone since the driveline is "disconnected". Did they say if the fluid that was drained looked discoloured? If I were you is find someone with a similar vehicle or test drive a vehicle dealership and see if it feels consistent with your vehicle. If the differential was bad you'll definitely hear a whine from the rear at higher speeds but it is possible that yours is going if it has been getting progressively worse. Tough to diagnose something like that over the internet.

[Jayskywalkers7]

Depending on how severe the vibration is I feel like what you're feeling is the normal quattro rumble. On vehicles with sport differentials the rumble is a lot more pronounced. Typically if it only happens on sharp turns with your steering wheel at full lock I would think that is normal. Once you're at full lock and you put it in neutral it is expected for the rumble to be gone since the driveline is "disconnected". Did they say if the fluid that was drained looked discoloured? If I were you is find someone with a similar vehicle or test drive a vehicle dealership and see if it feels consistent with your vehicle. If the differential was bad you'll definitely hear a whine from the rear at higher speeds but it is possible that yours is going if it has been getting progressively worse. Tough to diagnose something like that over the internet.

I would have to agree as well I had a 2016 s7 same rumble when I turned at parking lot speeds at full wheel lock. Brought it to Audi and they said this is typical for a lot of vehicles with quattro especially mine since I had 20" wheels and that there was nothing wrong with it at all. The car ended up being fine for the next 20-25k miles before I totaled it.

[Audisthesia]

If I'm at low speeds full turn I get the rumble. Didn't come as a surprise to me as my 4x4 truck also does the same thing when in 4wd mode, slow, and fully turned.

[MattyMarkey]

Dang, how much rumble are you all talking about? haha. Parking lot speeds, I get the quattro "noise" I would call it, but to call it a rumble or vibration, I personally wouldn't go that far. Comparing it to a 4x4 like my Jeep, there is no comparison, to me anyway. My failed/failing sport diff did not have any whine at higher speeds going straight down the road.

Cruising speeds that the OP also states he is at, I don't have any rumble/vibration.

In my experience: to narrow it down to the diff, the dealer had someone driving, while someone is sitting in the back with the trunk open, driving in the parking lot, driving side-to-side aggressively. Should be able to hear it better

[Spitfire007]

1: rumble NEVER existed until it quietly started after the 45k service.
2: it's a vibration at less than full lock, at a variety of parking lot speeds.
3: it's getting worse and worse, to the point where my 6 year old asks me what it is.
4: dealer said it's definitely noisy...unusually so, and that it can certainly be felt, but they're useless.
5: front/center/trans fluids were changed, looked normal.

I'm sorry, but it's not normal, especially since it's getting worse and worse over time.


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[Audisthesia]

Dang, how much rumble are you all talking about? haha. Parking lot speeds, I get the quattro "noise" I would call it, but to call it a rumble or vibration, I personally wouldn't go that far. Comparing it to a 4x4 like my Jeep, there is no comparison, to me anyway. My failed/failing sport diff did not have any whine at higher speeds going straight down the road.

Cruising speeds that the OP also states he is at, I don't have any rumble/vibration.

In my experience: to narrow it down to the diff, the dealer had someone driving, while someone is sitting in the back with the trunk open, driving in the parking lot, driving side-to-side aggressively. Should be able to hear it better

You can call it Quattro noise Rumble whatever you want but it's subtle and nothing out of the ordinary. I know it does not compare to the 4x4 that one is clearly just the difference between the front and Rears and the differentials and the tires not getting the same amount of rotation per distance. Was just trying to say a subtle noticeable change in the steering feel or drive pattern when all wheels are Drive Wheels is normal

[Audisthesia]

1: rumble NEVER existed until it quietly started after the 45k service.
2: it's a vibration at less than full lock, at a variety of parking lot speeds.
3: it's getting worse and worse, to the point where my 6 year old asks me what it is.
4: dealer said it's definitely noisy...unusually so, and that it can certainly be felt, but they're useless.
5: front/center/trans fluids were changed, looked normal.

I'm sorry, but it's not normal, especially since it's getting worse and worse over time.


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What I am describing on my car has always existed. It only occurs with the steering wheel turned fully one way or the other. It really doesn't make any sound it's more of a steering feel. What you are describing sounds different in the fact that it has gotten louder or more pronounced over time tells you it's not normal

[Spitfire007]

It does NOT require full lock either...just when making a 90 deg and under load. As soon as I pop it into neutral the sound AND vibration goes away.

It's so strange, and no one seems to be able to figure it out.


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[MattyMarkey]

It does NOT require full lock either...just when making a 90 deg and under load. As soon as I pop it into neutral the sound AND vibration goes away.

It's so strange, and no one seems to be able to figure it out.


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In my novice experience, and internet descriptions, it still sounds like diff related. It just sounds too similar to my own experience. Hard to pin point a drivetrain issue, when you are just driving the car - my diff issue sounded like it was coming from the front passenger fender, but also the passenger rear fender when driving.

You can visually see issues with the driveshaft support carrier. Wheel bearings should be able to check. Truly ask them to have someone sit in the trunk of the car and drive around, as weird as it sounds lol.

FYSA: You can buy used good diffs for MUCH less than new. Just need a dealer to code the replacement in ODIS

[Spitfire007]

Thanks!!
I'll be sure to suggest that next time


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[rlny]

100% normal


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[Spitfire007]

100% normal


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I appreciate your input, but how did it go from being dead silent with NO vibration, to what I have now, which makes me cringe. It now does it when parallel parking and reversing. Which it NEVER did before.
I dunno how I feel about just waiting for something to break....


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[will.k.315]

I've got this groan when doing low speed maneuvers at full or near full lock as well. I also have been occasionally getting a howling/growling noise on occasion that sounds similar to my front diff sound on my Silverado SS that needs to be replaced. Luckily I'm under warranty for another 10k miles so I'll get it checked out eventually.

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[TheBlackMarvel]

I wanted to follow up on this thread as my car had developed a pretty nasty grumble on low speed sharp turns about 6 months ago. Just coming out of my parking garage was enough to trigger it and pulling u-turns felt terrible and worst when the car was cold. I know my car didnt always make this sound because when I was shopping for an A6, the first one I test drove had that issue and I had asked the selling dealer about it. The second one I drove, which I ended up buying didnt make the sound and I felt better purchasing it knowing there were no strange vibrations.

Anyways, at 55K miles, ~7.5K of which were Stage 2, after reading this thread I decided to change the front diff fluid to see if I could address the grumble. The fluid that came out did not seem bad at all. Darker than what went in, but it was a dark maple sirup color at worst and didnt smell terrible as diff fluid often does. To my surprise, its totally fixed the issue. The grumble is gone. Hot or cold, sharp or wide turns. All smooth. Im amazed.

Thank you to this amazing forum!

[will.k.315]

I wanted to follow up on this thread as my car had developed a pretty nasty grumble on low speed sharp turns about 6 months ago. Just coming out of my parking garage was enough to trigger it and pulling u-turns felt terrible and worst when the car was cold. I know my car didnt always make this sound because when I was shopping for an A6, the first one I test drove had that issue and I had asked the selling dealer about it. The second one I drove, which I ended up buying didnt make the sound and I felt better purchasing it knowing there were no strange vibrations.

Anyways, at 55K miles, ~7.5K of which were Stage 2, after reading this ahead I decided to change the front diff fluid to see if I could make it go away. The fluid that came out did not seem bad at all. Darker than what went in, but it was a dark maple sirup color at worst and didnt smell terrible as diff fluid often doest. To my surprise, its totally fixed the issue. The grumble is gone. Hot or cold, sharp or wide turns. All smooth. Im amazed.

Thank you to this amazing forum!

I'm going to have to try this as well. Definitely getting the rumble and I'm at 68k miles.

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[Spitfire007]

So, rumble is still there, have changed out all diffs and trans fluids.

HOWEVER, if the car is sitting for 3-4 days, and I take it out of a parking lot requiring lots of sharp 90 deg turns, there is NO vibration or noise AT ALL.
It takes a couple of miles, and then it's back. That leads me to believe there may be a way to make it go away....but I can't figure it out.

Weird.


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[Alabama]

HOWEVER, if the car is sitting for 3-4 days, and I take it out of a parking lot requiring lots of sharp 90 deg turns, there is NO vibration or noise AT ALL.
It takes a couple of miles, and then it's back. Weird.

Definitely weird. Something heats up with driving, changes dimension and starts to vibrate? One of the pumps? Maybe you can record the sound and post it for the experts here to listen to.

[Spitfire007]

I mean....call me crazy here...but could it just be a really rough wheel bearing, but only in slow and sharp turns?
It's silent and smooth everywhere else....


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[MattyMarkey]

I mean....call me crazy here...but could it just be a really rough wheel bearing, but only in slow and sharp turns?
It's silent and smooth everywhere else....


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Wheel bearings typically don't cause vibration/rumble when going bad, just much louder "road noise" when turning. Doesn't hurt to have them checked out at this point though. Would really need to hear it or get a second shops opinion at this point to go any further with ideas