Engine driven unit, comprising an internal combustion engine, a cooling circuit for said internal combustion engine, and a pressurization system for said cooling circuit, said pressurization system, comprising: - a coolant tank integrated into the cooling circuit, - a pressure source comprising an air pump, - a pressurization line connecting the air pump and the coolant tank for pressurizing the coolant tank, and - a control unit for controlling the operation of the air pump, wherein the pressurization system further comprises at least one pressure sensor disposed to detect a pressure within the cooling circuit, such pressure sensor is connected to the control unit to communicate pressure data representing the detected pressure to the control unit, and the control unit comprises a data interface for receiving status data representing an operation state of the engine driven unit, and the control unit is provided to control the operation of the air pump so as to regulate the pressure within the cooling circuit to a pressure level that is determined on the base of the present status data received via the data interface, wherein the power of said air pump is variable and it is controlled to be raised or lowered to respectively increase or decrease the pressure within said cooling circuit, and wherein said status data comprises at least the engine ignition status, indicating if the engine ignition is activated or not and a cooling system temperature status, indicating if the temperature within the cooling system is higher than a predetermined temperature value or not. - a coolant tank integrated into the cooling circuit, - a pressure source comprising an air pump, - a pressurization line connecting the air pump and the coolant tank for pressurizing the coolant tank, and - a control unit for controlling the operation of the air pump, wherein the pressurization system further comprises at least one pressure sensor disposed to detect a pressure within the cooling circuit, such pressure sensor is connected to the control unit to communicate pressure data representing the detected pressure to the control unit, and the control unit comprises a data interface for receiving status data representing an operation state of the engine driven unit, and the control unit is provided to control the operation of the air pump so as to regulate the pressure within the cooling circuit to a pressure level that is determined on the base of the present status data received via the data interface, wherein the power of said air pump is variable and it is controlled to be raised or lowered to respectively increase or decrease the pressure within said cooling circuit, and wherein said status data comprises at least the engine ignition status, indicating if the engine ignition is activated or not and a cooling system temperature status, indicating if the temperature within the cooling system is higher than a predetermined temperature value or not. wherein the pressurization system further comprises at least one pressure sensor disposed to detect a pressure within the cooling circuit, such pressure sensor is connected to the control unit to communicate pressure data representing the detected pressure to the control unit, and the control unit comprises a data interface for receiving status data representing an operation state of the engine driven unit, and the control unit is provided to control the operation of the air pump so as to regulate the pressure within the cooling circuit to a pressure level that is determined on the base of the present status data received via the data interface, wherein the power of said air pump is variable and it is controlled to be raised or lowered to respectively increase or decrease the pressure within said cooling circuit, and wherein said status data comprises at least the engine ignition status, indicating if the engine ignition is activated or not and a cooling system temperature status, indicating if the temperature within the cooling system is higher than a predetermined temperature value or not.