Intermittent whirring noise - driving me crazy!

[JimmyPop]

I'm just wondering if anyone else has experienced similar. I have an intermittent whirring noise which appears to be coming from the rear of the car. It's only noticeable above 35mph and doesn't seem to happen every time I go above that speed. I'm sure it's still there when I go faster but engine/road noise seems to drown it out. It seems to disappear when I slow down below 30mph. It gets slightly louder with road speed and engine speed doesn't appear to affect it. It happens both in gear and in neutral and with or without my foot on the accelerator.

The noise itself sounds almost like an electric motor. I've looked around on the forum and I see some people have experienced similar from a variety of causes. I'm just wondering if anyone else has any ideas? I've been told my suspension bushes are a little soft, but this wouldn't account for the noise, would it?

And before anyone makes any jokes - no. It isn't the sound of a might 4-pot engine and it's not the other half

 

[Mike_89]

I have exactly the same problem on my 3.0i no noise up to about 30 or over 50 but in-between I have the whirring which you have described! It's so annoying I have no idea what it is, though I suspect it may be a wheel bearing but having jacked the car up im not sure as there's no play in them at all?
Also it may be a coincidence but I have also being told my front suspension bushes are a little weak but like you I doubt this is the cause of the whirring.

 

[JimmyPop]

How odd- since coming back from the Islay run, I haven't heard the noise once!

I wonder what vital bit of my car fell off....