my radiator split by the fill cap couple off weeks back so replaced with new rad . stopped at work yesterday and noticed hissing and bubbling coming from expansion bottle . so let motor cool down for 3 hrs and removed rad cap still lots of pressure . lost about half cup of water . replaced cap and started motor top rad hose gets rigged straight away . turned motor off slowly released rad cap to big hiss and white smoke boo hoo . think head has gone so can i get an upgraded one ? were from and for how much please help? i love the old beast and use it every day 4 work its a 3 litre turbo diesel