Vibration highway speeds

[Jprieur]

2021 TTRS: Long story short, have had off and on vibration (steering wheel) around 80/85 mph since the car was new. Car originally had the OE P Zeros and noticed severe vibration right when we bought it, dealer verified and did a road force, moved the lowest road force readings to front, etc.

Installed a set of 4 PS4S after 2 failed attempts on the OE P Zeros, get them roadforced and one is right around 23 lbs so I get that one tire replaced. Dealer does another road force with the new tire and gets all 4 down to 12 lbs or below. I am still getting some vibration around 85 mph, it's better overall but its still there (sometimes it's barely noticeable, so its now sporadic at least). Note the front tires are both below 8 lbs road force (and the vibration is in the steering wheel so this is confusing me a bit).

I know these are incredibly low profile tires with very little margin and obviously it's a very sensitive suspension setup; but has anyone else had ongoing issues with highway vibration? I am going to try and have the dealer check the wheels next, but I assume if the wheels were the issue the Hunter Road Force machine would diagnose that as I do believe it check that as well during the process. Any thoughts?

[Thumper3]

Any thoughts?

Go the speed limit?

Seriously, while wheel balance is the most obvious culprit of vibrations in the steering wheel I feel like that has been pretty completely covered (different tires, multiple balances, moving tires around, etc). I mean if you've even changed tires and the same issue remains, it might not be the normal issue but something else in the suspension or rotating assy. You know what they say, if you rule out the possible, then the remaining, no matter how improbable, must be the issue. Heck, makes me wonder if maybe there's a small defect in the steering gear (electric with feedback afterall) where it's causing vibrations with the motor? Wild and crazy to even say but hey.......no idea why speed would matter there either but as complex as these cars are now, I've seen some crazy stuff.

I tracked the OE P Zeros and never had vibrations at any speeds, I've been running the PS4S's (on different wheels) and have not had issues and neither required more than one balance.

[McTTRS]

Go the speed limit? [:D

Heck, makes me wonder if maybe there's a small defect in the steering gear (electric with feedback afterall) where it's causing vibrations with the motor? Wild and crazy to even say but hey.......no idea why speed would matter there either but as complex as these cars are now, I've seen some crazy stuff.

If this is the case then perhaps changing the drive select setting will impact the problem.

[GaBoYnFla]

I've had the same issue on my 2022.....dealer comment was aftermarket suspension-H&R springs. Mine comes and goes too. Pzero's and I plan to replace soon with Michelins.

[Jprieur]

If this is the case then perhaps changing the drive select setting will impact the problem.

Ive tried changing modes (I actually have the fixed suspension so its not changing the suspension), and have also tried running the same speed in neutral; doesn't change and still have the vibration.

Ive also tried bumping up tire pressure, running for a while to warm up tires to rule out flat spotting of the tire.

Im at a loss. . . . wondering if maybe wheel bearings are the culprit

[Pharp]

Are you on stock wheels? I know on my S3 I had to run hub centric rings for some wheels that were a bigger hub bore then stock, it haunted me for a while till I figured out the lug nuts don’t center the wheel perfectly.


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[Jprieur]

Are you on stock wheels? I know on my S3 I had to run hub centric rings for some wheels that were a bigger hub bore then stock, it haunted me for a while till I figured out the lug nuts don’t center the wheel perfectly.


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Everything on mine is stock, no spacers. Dealer, in previous attempts to fix, was very careful in property mounting wheel to ensure no issues with uneven torque on lugs, etc.

[Over9000]

I vaguely recall one or two other cases of people chasing vibrations at highway speeds in here that ultimately ended up being traced to the brake rotors. Something else you may want to consider.

[steve111b]

Before you start tearing into the car looking for faults I would spend a lot of time checking the roads that you travel. The rollers used to pave today's roads can create ripples. New highways are more prone to have problems because heavy trucks tend to even out the ripples after a couple of years of traffic. Last Summer I found fresh pavement with huge ripples that were very clear even at low speeds. A few years ago I discovered long stretches of a new highway had ripples.

[Jprieur]

Before you start tearing into the car looking for faults I would spend a lot of time checking the roads that you travel. The rollers used to pave today's roads can create ripples. New highways are more prone to have problems because heavy trucks tend to even out the ripples after a couple of years of traffic. Last Summer I found fresh pavement with huge ripples that were very clear even at low speeds. A few years ago I discovered long stretches of a new highway had ripples.

I have ruled out pavement, so it's definitely not that. It has to be something rotational, so still thinking bearings or based on the input here rotors. I've always thought with rotors you would would have to have a massive deviation to feel vibration caused by rotors (when NOT braking).

[Jprieur]

I vaguely recall one or two other cases of people chasing vibrations at highway speeds in here that ultimately ended up being traced to the brake rotors. Something else you may want to consider.

Thanks, I did just notice that one of the brake rotors (pax side front) has some scoring where the rotor meets the disk. The other side is completely normal.

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[GaBoYnFla]

Thanks, I did just notice that one of the brake rotors (pax side front) has some scoring where the rotor meets the disk. The other side is completely normal.

17452BDD-F150-4892-B600-AC705D55095B.jpg35BC093E-0D8A-449D-9F8C-4BD5A9859CC2.jpg

I hear a lot of little rocks/pebbles between the shields and the rotors. Wonder if that is what could have happened to cause these marks?

[languiduck]

I know the thread is a few months old but did you ever figure out the source of vibration?

I know some people here will say drive speed limit, it's the roadway, wheels, tires, etc. Well I have my car in Germany and for some folks that get to drive 200+ km/h routinely the vibrations suck. Other than some mild local ECM tuning, the car is completely original. A new set of tires did nothing, I have OE Audi brakes and rotors. Several inspections have revealed nothing amiss. Maybe for me it's because I have a convertible, I can't tell. I say this because for the very brief period the weather here is appropriate to put the top down I have observed significantly less vibration at speed. I've tried playing with that automatic rear spoiler and it really doesn't change much. Only thing I've ever read is the rubber couplers on the driveshaft could be the culprit but they look fine and my car is low mileage.