My car engine plays up when its hot, but l noticed that l have lost the radiator cap a couple of weeks ago and since then it hasnt played up! can anyone tell there thoughts?

What is played up? Did it get hot? When you lost your rad cap you took the pressure off the cooling system. You probably have a leak

Its made by Citroen & should be spelt with ''Sh'' not a ''C''?.The reason u have a radiator pressure cap.is to raise the boiling point of the coolant!.if u dont pressurise the cooling system?.then the engine will over heat!.and may lead to engine head gasket failure or worse!.If l were you?. I'd get it checked out fast!.Sh1troen r not known for ''cheap''repairs.and ''ALL'' time is charged at .9 of an hour minimum?.so expect them to charge u for ''looking'' at it!.best of luck