Looking at a 2010 S4 auto with loud roar noise

[Westija]

All,

I am looking at a S4 auto with 70,000 km (44,000 miles) and the car looks really good and has several (not all) of its maintenance services done at the local dealer, but not the last couple. VIn is WAUZZZ8K3AA119788. I am located in Chile, South America. Roads here are not that great but not too bad, in general, but lots of speed bumps.

It drives fine and I am really tempted, but has a loud roar noise .

It has the OEM 18" wheels with Yokohama ADVAN NEOVA AD08 R, which is a summer performance tire. The tires still have quite a lot of thread life on them.

It is in need of new brake pads and rotors, as the rear pads are extremelly thin and when depressing the brake pedal you can feel they are pretty rough (noise, pedal feeling).

I am suspecting the roar is due to tire noise, but researching online it does not seems this tire is noisy, so I am not sure.

The noise/roar happens at low speeds and does not seem to change when switching weight from side to side (turning right and left). It happens also even when moving in neutral at the parking lot at very low speed (under 10 mph). It also continues as speed increases. It happens when the brake pedal is not depressed, so unless the pads are engaging somehow all the time, it is not brakes, I don't think.

The seller knows of it and I think I might be able to bargain the price down to cover a part of the tires cost, if I decide to move forward.

What else could this be? I am thinking that unless both sides wheel bearings are bad (not likely?) it is not that.

Could it be differential or transmission? Anyway to check that?

Thanks for the help

[Westija]

By the way, this is its configuration, just in case.

PRCode: 0G7 = Tiptronic
PRCode: 0JH = Weight category front axle weight range 8
PRCode: 0YJ = Weight range 9 installation control only no requirement forecast
PRCode: 1AT = Electronic stabilization program (ESP)
PRCode: 1BD = Suspension/shock absorption for special sports design
PRCode: 1KE = Disc brakes rear
PRCode: 1LJ = Disc brakes front
PRCode: 1N3 = Speed-related variable steering assist (Servotronic)
PRCode: 1SB = Additional engine and transmission guard
PRCode: 1XX = Leather trimmed multi-function sports steering wheel w/ Tiptronic
PRCode: 2K3 = Reinforced bumpers
PRCode: 3FE = Electric slide/tilt sunroof with sun screen/sunblind
PRCode: 3L4 = Electric seat adjustment for both front seats driver's seat with memory system
PRCode: 3NZ = Rear seat bench unsplit backrest split folding
PRCode: 3Y2 = electrically operated roll-up sun screen for rear window
PRCode: 4F2 = Central locking system Keyless Entry
PRCode: 4GF = Windshield in heat-insulating glass
PRCode: 4KC = Side and rear windows in heat-insulating glass
PRCode: 4UF = Driver's and front passenger air bag with front passenger air bag deactivation
PRCode: 4X3 = Side air bag front with curtain air bag
PRCode: 5D4 = Carrier frequency 315 MHz without panic button
PRCode: 5MZ = Decorative inserts stainless steel - fabric
PRCode: 5RU = Right exterior mirror: convex (large viewing field)
PRCode: 5SL = Left exterior mirror: aspherical
PRCode: 6XL = Exterior mirrors: with memory function automatically dimming electrically foldable/adjustable/heated
PRCode: 7A3 = CD player
PRCode: 7K0 = Without tire pressure warning light
PRCode: 7MG = Emission standard EU5
PRCode: 7Q0 = Without navigation device
PRCode: 7X4 = Park distance control front and rear
PRCode: 8BP = Bi-functional headlight with gas discharge lamp
PRCode: 8GR = Alternator 150 A
PRCode: 8K2 = Daytime driving light mode for urban driving
PRCode: 8Q3 = Automatic headlight-range adjustment dynamic (self-adjusting while driving)
PRCode: 8Z5 = Not hot country
PRCode: 9Q4 = Multi-function display/on-board computer with check control
PRCode: C2R = Alloy wheels 8J x 18
PRCode: D11 = 6-cyl. gasoline eng. 3.0 l/245 kW (24V) TFSI homogeneous Base engine is TC6/TE8
PRCode: E0A = No special edition
PRCode: F0A = No special purpose vehicle standard equipment
PRCode: J1U = Battery 450 A (95 Ah)
PRCode: N1U = Silk napa leather seat covering
PRCode: Q4Q = Sports front seats
PRCode: S4Y = Region
PRCode: TC6 = 6-cylinder gasoline engine 3 L unit 06E.C
PRCode: U1A = Instrument insert with km/h speedometer clock tachometer and trip odometer
PRCode: X9T = National sales program South America

Thanks

[Johnnycash]

do you have a dealership where you can bring the car to have an inspection done?

noisy tires are annoying but do not typically make a "loud roar" but if english is not your first language some thing may be getting lost in translation?

[KurTecH]

Could be a wheel bearing going bad. Just not enough to impact the way it drives yet.
Something like this (minus the shaking): https://m.youtube.com/watch?v=QPf2ibWgBm8

When I went from my super bald summer tires to my newer winter tires, it had a major increase in road noise it was almost disturbing.

[Westija]

An inspection is definitely a good idea. I will do that, thank you.
If I can get some hints to what this could be I can probably point it to the dealer for a more careful inspection. You know, I am not that confident in a dealer diagnostic.

In reference to the noise , it sounds like bad wheel bearings, but does not change as I load each side, so I suspect it is not that. It could be tires, but would tires be loud enough that you can feel at a very slow speed? These are quite grippy.

Thank you

[Westija]

KurTech,

Not exactly like that video, but, similar to this https://www.youtube.com/watch?v=UpsLaSzcAu4 (your link led me to that). BUT, no changes as I shift the weight from side to side, like in the video.

Thanks

[dizzlesizzle]

if i had to pick prob a wheel bearing

[KurTecH]

Do you notice any vibrations at all?
I would think it's most likely wheel bearing, but it could also be a differential noise as well.
I would make sure wherever you take it hears the noise and you ask them to take a look at the wheel bearings and check the differentials.
I'm not super familiar with the center diff/Quattro system yet, but I've had rear differentials go out on other cars I've had that made a really bad noise as well.

[jygesq]

Never buy used car that you have doubts about from the beginning .what else could be wrong. Certainly do not buy used car w/o a long warranty.I would pass

[Westija]

There are no vibrations. I am surely taking for an inspection, before anything, if I decide to proceed.
Thanks

[dzasta]

just an fyi, i just replaced an older set of conti DWS tires with the newer DWS 06 tires. after putting the new tires on the car the sound difference is night and day. it is so quiet now that it feels like totally different car. i thought i had a bearing issue but my dealer confirmed the bearings were fine when i did my 55k service. just another data point for you.

the only bad thing is that since the car is so quiet now i now hear a couple more squeaks and rattles in the interior.

[chaos2984]

if your driving and hear the noise at speed and you shift the trans into Neutral does the noise pitch change at all. if thats the case its either a wheel bearing or in the Diff. Does the noise change pitch if you push on the acell pedal and let off. If the noise is the same regardless of throttle input then its not a diff problem and more likely a wheel bearing issue

[Westija]

UPDATE:

Followed advice and took the car to the local Audi dealer. I rode with their technician while he drove to troubleshoot it.
Noise did not change when riding in Neutral. Not as noticeable immediately after accelerating (when under lower load in front wheels) and increase under breaking. No significant change from side to side. Tech thinks it is front wheel bearings.
I made an offer under the condition of have the noise resolved/fixed.
Owner taking the car to the shop today and should know next week if all will work out.

Thanks for the help

[anerbe]

Have the dealership swap wheels/tires with another car that for sure doesn't make noise and evaluate your car.

If it goes away, you have your answer.

[Westija]

Swapped tires with an S5 and noise was gone. Decided to buy the car and now I have a noisy tires S4. One more reason to drive it hard and wear these out, so I can put new ones in.

Thanks