Combustion engine and operating method

The system (1) has a fresh air-system (4) for supplying fresh air to an internal combustion engine (2) i.e. piston engine, and an exhaust gas system (6) discharging exhaust gas from the engine. An exhaust gas turbocharger (8) has a turbine (10) arranged in an exhaust gas pipe (7) of the exhaust gas system. A compressor (9) of the turbocharger is arranged in a fresh air pipe (5) of the fresh air system, and a bypass valve (14) adjusts desired bypass flow. The bypass valve is designed to generate the bypass flow as a pulsed bypass flow through alternate opening and closing of a bypass (12). An independent claim is also included for a method for operating an internal combustion engine system.