Zile mate welcome on board! You don't need to replace anything until you investigate further. The fans can often run when you switch off the engine, of course they will try to cool the engine a little. Of course when you purchase a car then a full service is a good idea so you know that oil, filter and fluids are all good. BUT this may not change the fans, that depends on the thermostat which is a weak link on these cars so may be worth changing. Keep us informed!! Simon