DiscoStevey wrote:

I have noise on my D4, 2010, 93k which is really bugging me but I can't seem to track it down.

The noise sounds like someone blowing across the top of a bottle. You can hear it inside the car, but not with the windows down. The pitch stays constant, only the volume changes slightly as you put more throttle on. It's never deafening, but it's there. It starts as soon as you touch the throttle, lift off and it stops. Rest your foot on the gas to maintain speed and its there, ever so slightly hooting away. It's all the more frustrating because it doesn't do it all the time. For example, it won't do it on the way to school in the morning, but it might do it on the way back. It also seems to match a slight vibration felt through the steering wheel.

I assume if it was a bearing or a rotational noise the pitch would change with revs or road speed. It doesn't do it when stationary, only under load. It's more pronounced when pulling away uphill.

The odd thing is I filled up with BP Ultimate for a change a couple of weeks back as we were off away for the weekend and it only occurred to me when we got back that the noise had gone away. It's returned since...

Performance doesn't seem to be affected and there were no faults logged when they replaced my handbrake module two weeks ago.

It's due a fuel filter change and the BP incident made me wonder, if the filter is clogged could it be the high pressure fuel pump whining a bit? I would expect the pitch of that to change with revs, as it's driven off the crank isn't it?

Any pointers would be appreciated. Oh, and every boost/vacuum hose I can identify and access has been checked more than once