Hunting engine bay sounds

Gday,

I'm at a loss. I've consulted numerous buds and several blokes who are very good mechanics but I think this question comes down to experience.

Recently did Timing belt, oil pump and water pump on my IX, 184k km old. Replaced with Gates belts on both the timing belt and the accessory belt, GMB timing pulleys throughout, brand new OEM Idler pulley.

Getting an odd noise from what seems to be the engine cover/cam gear area, its like a echo-y rotational racket, almost sounds like something is loose but we have re-checked everything and its all torqued to spec.

Figured I'd open up to some expreienced hands to see if anyone recognises a sound thats going wrong in there.

Cheers in advance.

https://www.youtube.com/watch?v=MLI4nK5s0jk