SixStick

Yes I finally replaced both front bearings and that proved to be the source of the problem. While I replaced many parts while trying to find the source of the noise, the result is that the car rides and handles the way it was when new and is a pleasure to drive in all conditions.

The only thing that still seems strange to me is that this all started when I picked up the car from the tire installer. The car made no noise when it went in and then had very noticeable noise when I picked it up at the end of the day. I guess I'll never know.

GTA_Driver

Sometimes new tires will change the angle or the resistance the wheel puts on the bearing.

JRomulus

Wow Six, that is a frustrating story. I've bought Conti's and had them installed at a Sears, etc., but I would be livid IF they did something to the vehicle just putting on tires. Just the time you had to spend, much less the $. Glad you got your vehicle back to normal.

I am dealing with what I think is a bad bearing issue, at the dealer now waiting as they inspect and do the 15K service.
Steady hum from the rear at 20 to 45, getting higher in octive until the harmonics (almost) vibrate your teeth at 75.
Issue started in early August and has gotten worse since. My wife actually noticed it before me, cause I tend to blast the music.

Went through the usual routine: changed the summer tires yesterday, still the sound. Got on the highway got it up to 75 and switched into neutral, still the sound. Like to run my air pressure higher, so reduced the rear 18" all seasons down to 32 lbs from 36, a tiny bit less sound, but still there.

She wouldn't drive me around in the trunk so I could localize, it, but think it's the driver's rear bearing. We'll see. Seems odd that it could be that at 15K miles, but maybe the Audi Club of America autocross event I did later in August exacerbated a minor bearing defect, who knows.

Tilyk

I know it's not an audi but now have an A6, I used to have an e350 merc changed tyres to continental all weather and when slowing down it sounded like the back axle has let go. Changed tyres for pilot sports sound and noise gone and perfect. Means you had the noise after the tyre change I would suggest it's the type of tyre you had fitted.