Vauxhall Vectra strange engine/turbo noise when accelerating

get your engine checked it sounds like you engine has a major fault.
is it using a lot of water?
oil?
loss of power?

As you say you are losing water , it would be best to see where from and rectify fault . It could be too late and head gasket gone if cooling system pressurizing .

found a split in the turbo pipe but cant understand why its loosing water there is no oil in the water or water in oil but it does chuck it out the expansion tank but only when you put your foot down and the turbo screems and bangs