A method is provided for detecting faults in a pump assembly having an electric motor, or faults in an electric motor, having at least one rotating shaft. A vibration signal is detected, the detected vibration signal is processed in a manner such that the influence of the current rotational speed of the shaft is eliminated, periodic signals are filtered out of the processed vibration signal, and the vibrational operating condition, in particular possible faults, is recognized by way of the periodic signals. Further, a pump assembly having an electric motor or an electric motor is provided in which this method is applied.