Very feint whine on light throttle

[Nick_B]

Hi All,

I think I may have this noise for a while – but maybe starting to be aware of it more. It is best described as a feint hight pitched whine from the front end when cruising at a constant speed 60 – 70 mph) with a very small throttle opening. Coming off the throttle the noise goes away, apply a little more throttle (to accelerate or if needed to maintain speed) the noise goes away, knock thew box into neutral, the noise goes away.

Changing down a gear does not seem to make a difference – it seems related to road speed not RPM – and a very small throttle opening / small load on engine / driveline.

Most of the time it is drowned out by the normal noise of 19” wheels – so most noticeable on a perfectly smooth road surface.

I have had the car from new (2019 A4 40 TDI S-Line – DSG). Mileage is high now (160k) but up to date on all services / DSG fluid changes etc…). Car drives fine, no knocks, vibrations etc… and the gear shifts are smooth.

Interested in any ideas.

 

[northpole]

could be a wheel bearing on it's way out...

 

[spartacus68]

If it's the bearing, then it's bolt-on, which is a good thing. At 160k miles it's likely welded on with corrosion and you'll need an air hammer to shift. I've always found wheel bearings difficult to diagnose, especially with road wheels on, and they rarely knock as in lateral movement. If you're fitting, fit FAG and do both front corners. Useful video here if you're doing it yourself. This is on B8, but B9 is likely the same.


View: https://www.youtube.com/watch?v=zYzqgS8XW-E&t=1628s

 

[Nick_B]

Thanks for the advice - I was wondering if it could be wheel bearing related. However - if wheel bearing related - would the noise not continue after backing off the throttle? In my case the whine disappears when back off the throttle (and is only audible between 65 - 75 mph).

 

[SuperV8]

Have you changed both DSG oils?
Both my front wheel bearings recently failed (Seat) but it was a faint rhythmic whoomp whoomp noise.
Are your tyres good? Simple to switch your tyres front to back to see if the noise changes?