Can anybody help???....I have a 54 plate 1.7 cdti astra. A few weeks back I was driving down A1 when car cut out due to a hole in a pipe in cooling system. The dip stick had shot out due to pressure and over heating. I filled the car back up with water and managed to get home. I replaced the pipe and the car drives perfect. However, the water is disappearing. There are no typical signs of the head gasket blown i.e. creamy on oil filler lid etc. There is normal power also. There is a noise coming from header tank, either air being sucked in or blown out. Can anybody help please.