Baloo588

It gets more complex after you keep rotating the tires which is why I stopped rotating the tires on all of my cars including Audi because they have perfect 50/50% tread wear and when I rotate I get more vibration so its annoying. I would get them all road force balanced or replaced if needed.

andrewmr

This is exactly what I've found with rotating tires. Just leave them where they are.

DavidA

Got P Zero Neros that are very smooth/ no alignment at 53k miles; look in to them for the rear where the ride makes a difference!

TimInNOVA

Balboo588: I took the A8 to dealer on 12/29 and the tech confirmed the vibration in the floor and seat. I hinted to him about the drive-shaft. They gave me a loaner and looking into it.


goliath1: This thread is focused on a vibration in the A8 chassis, felt in the seat and floor; not the steering wheel. Also, this particular vibration is not constant, put pulsates and only occurs between 35-45 MPH. Good luck with solving yours.

pcarchicago

I've just joined the forum, brand new to me owner of a 2013 A8 3.0T SWB. Love the car but am having the same type of vibration when decelerating-no gas or brakes being applied while driving around town..

TimInNOVA

I heard back from the dealer on Friday and they have ordered two new exhaust "flex pipes" and brackets (4H4253300F & 4H4253350F). They feel this is the cause of the pulsing vibration. It may take some time for the parts to get in, as they are coming from Germany. I'll update the thread again once they are installed and I've road tested it.

Jack88

That sounds like a shot in the dark. I don't see how it even makes sense.

tbellows

I bought my 2013 A8L 3.0T two months ago. Needed new tires so I had the Pirelli's put on that day. Old tires were pretty worn and load. Had them load forced balanced and also had the rims checked before mounting the new tires.
I have a low pitch vibration/humming at low RPM's usually around 1100-1700 rpm's.
I took it to the tire dealer. They rechecked the balance and rotated the tires. Same thing. No change. Took it back again. The took the Pirelli's off and put Goodyear Eagle's on. Same thing. Vibration at the same rpm's.
You can't feel it in the steering wheel and it does have an almost harmonic rhythm to it. Tire center took the Goodyear's off and tried Continentals just to make sure. No change.
Ok. So its not the tires or rims. Here's what I found. If I switch to manual shift and when I am cruising at say 45mph and it's running in 7th or 8th gear at 1200-1300 rpm's, I down shift to 6th, still there but when I shift down into 5th it disappears immediately. Shift back to 6th or 7th and comes back just as quick.


Any thoughts before I take it to the dealer next week?


Thanks


Thom

Jack88

It seems to be a harmonic in the suspension. As far as I know no one has found a solution. If they have, they've kept it to themselves and haven't shared. I have heard reports of Contisilent tires minimizing the effects, but I haven't first hand experience to back that up.

TimInNOVA

Update: I picked up the car and the vibration was still present. I went back and grabbed the mechanic and he agreed. A real PIA that I had to do this, one would think they would test drive it after the repair.

Anyway, they have the car again and are opening a case with TAC (whatever that is). The mechanic suspects it may be a motor mount and will inspect them all.

The saga continues. I'll post again when I have some new information.