Cooling water and hole in the motor

Hello everyone, My friend called me yesterday and said he bought a new car, a Volvo v70 t5. As far as so nice, test drive ran without problems, only with the transfer the car stopped. Temperature was normal, however, no cooling water was available anymore. Am then to him today, because I could not get a picture of it at the beginning. He dumps water into the tank and shortly afterwards it ran through a small hole (about 1.5cm) slightly above the oil tank, directly behind the drive shaft holder again out. Now my question, where could the water come from and what would you do because of the hole? Because of the hole my acquaintance, who wants to cold-weld, should I talk to him there or rather advise him from? Thank you already in advance