Can I just ask someone to try this plse?

When I wobble my steering wheel, with the engine off, left and right off-center (just slightly, perhaps an inch either way), I get a soft clicking noise coming from the engine bay. However when I have the engine (and therefore power steering) running, there's no noise at all.

There is also no noticeable slack in the system. When I move the steering wheel just a tad, I can see the front wheels moving in response. This happens both with the engine on/off.

I'm just wondering where the clicking noise is coming from. Is it a U-joint in the steering column, or between the pinon and rack in the power steering rack?

tks.