Banging noise when turning wheel left and right lock

[Rwisch]

I'm looking at buying a 04 A4 3.0 Quattro. While test driving I hear a single bang or knock when turning the wheel all the way left or right. Is this a big problem/expensive. The vehicle has 40k miles.

[Luxus Panzer]

No way to know.

Jack it up and have a look at all the suspension components. Or you can pay a hour labour to have a indi VW shop inspect it for you.

[Seerlah]

Most likely ball joint of control arm or tie rod, or cv joint. My car does the same, and have been too lazy to figure which conponent it is (passenger side). Kind of dangerous, actually.

[ADCS]

While moving or while stationary?
It could be as simple as the bellows over the inner tie rods collapsing on itself making a loud singular pop noise. As they age and dry out they do that.