that dont mean jack with KV6's - does it sound like a rattly noise from the engine compartment - in which case its VIS valves.
or is it the water header tank bubbling away?
it is def not a bubbling or rattle noise. More of a whine. Maybe i am being daft and the noise is supposed to be there. without that noise tho my v6 would be silent from inside (unless putting my foot down of course and getting the little roar)