BMW S54 cold start engine noise rattle

BMW S54 cold start engine rattle appears to be coming from underneath the #1 cylinder throttle body.

[@pish180]

very helpful. thanks

[@rocketbmw]

It ended up being the water pump that was making this noise. New water pump, no more noise.

[@tnereffidxmitch]

sounds like a piston pin with excessive clearance.

[@fijitec]

VANOS