Car leaking oil and coolant ?

My sons car was overheating so instead of stopping he sped up to try and cool then engine down!! This worked periodically but when he stopped he heard a "pop" and the car wouldn't start. The AA man looked at it, shock his head and towed him home.

Any advice as to what is wrong. The car is a 1997 Citroen Saxo VTR 1.6

Thanks

Emma
February 2009