I think it is probably a disc problem ,the power steering is electric on a diesel I presume petrol engine is the same,
You wont notice a warped disc with the bear eye.I've done a video (audio is quite clear too) I'll upload it tonight - Silly 3G connection keeps on failing on me.
Silly question - If I take the wheel off would a warped disc be pretty visable? Or is it only a couply of mm? If I lay a straight edge (metal ruler or similar) across it would this be enough to pick up any high/low points?
Edit: P.s. Thanks for the replies