Humming noise between 30-40mph

[Lord Vader]

Now I have done the n/s bearings as I thought it was coming from there and the o/s seam ok on jacking it up and checking, any other thoughts or previous similar problems encountered?
Thanks in advance!

 

[simch]

ONE WORD!! TYRES!!

Its nearly nearly always the tyres on these S3s that cause hum!

How old and what type are they, Dunlops and harder tyres like Avons are notorious for it!

Mine was drivine me mad I was convinced it was tyres though and I was right! ! Previous owner had two rear wheel bearings though from Audi, to no avail!

 

[Lord Vader]

Funny you should say that, someone else said tyres and I wouldn't have it.
Oh well i'm getting new wheels soon so I see for sure then!

Oh they are toyos on the front and goodyears on the back.

 

[simch]

My monies on the rears!

Swap front to back and see if the noise moves...

Never had it on any car but the s3...!?!?

 

[madvw]

i bet its from the rear too - either a bearing or the tyres. When a rear bearing went in my corrado, it sounded like it was from the the front.

 

[Stewart]

Yep, would put my money on tyres as well, try altering your tyre pressures and see if the pitch of the noise/humming changes.

Also if your car is lowered you will have more negative camber which 'seems' to excerbate the bearing type noise.

 

[Lord Vader]

Good thinking about the negative camber, as when i did the n/s bearing I took out the negative camber (the three bolts on the bottom of the wishbone) and it did get a bit quieter.
I will try changing the tyres around.

 

[S3 NIK]

My car made the very same noise, once i replaced the rear worn tyres the noise vanished.
Nik.