2.0 knocking/Rattle under load road speed tempo

[ScottFree]

Hi all,trying to diagnose a problem on a recent private purchase it's a 2012 A6 2.0 tdi manual.

I seem to get a front end hollow sounding clicking/Knocking noise which starts around 20mph and is a gently tap to full on machine gun and 50mph and upwards more of a buzzing.

It's a consistent tempo so I think that rules out bushings etc,I've had new discs all round to rule them out.

The noise shows itself under Acceleration/Deceleration and disappears when I press the clutch in.

This would normally point to clutch/Flywheel but the noise is consistent with wheel/Road speed rather than rpm and the Noise isn't there when idle or revving up just under wheel speed load

I've also had a feel of both Drive shafts/CVs but all seems solid and wheel bearings have no play/rumble and it's not wheels/tyres

Any suggestions? Thanks

 

[Slackworth]

I've had a number of wheel bearings go on my A4 and A6 Quattros. (they all use the same part so clearly a weak point on them!) In fact mine is going in on Friday to have the OSF done - this will be the 5th wheel bearing between the two cars.

The symptoms match up 100% to what you describe to being a wheel bearing other than the clutch being pressed in stopping the noise as mine does it regardless.

 

[fingermouse]

Not something daft like a nail in a tyre ???