METHOD AND DEVICE FOR MONITORING AN EXHAUST GAS TURBOCHARGER OF AN INTERNAL COMBUSTION ENGINE

A method and a device are described for monitoring an exhaust gas turbocharger of an internal combustion engine, which allow a diagnosis of the oil supply to an exhaust gas turbocharger. In at least one operating state of the internal combustion engine, a variable that is characteristic for the rotational speed of the exhaust gas turbocharger is ascertained. A variable that is characteristic for the rotational speed of the exhaust gas turbocharger is ascertained in the at least one operating state of the internal combustion engine. An operating state which is characterized by a change in the exhaust gas mass flow, which is linked to a change in the variable that is characteristic for the rotational speed of the exhaust gas turbocharger within a predefined tolerance range, is selected as the at least one operating state. A fault is recognized if one or more values outside the predefined tolerance range are established for the change in the variable that is characteristic for the rotational speed of the exhaust gas turbocharger in the selected operating state.