Method for operating an active oil separator for separating oil from exhaust air of a crankcase of a motor vehicle having an internal combustion engine , comprising the following steps: - identifying an engine operating state of the internal combustion engine by means of an identification device , the engine operating state being determined by an engine load (ML) and/or an engine speed (MD) of the internal combustion engine , - determining a first TARGET speed (S1) of the oil separator on the basis of the identified engine operating state and a first characteristic map (K1) by means of a determination device , the first characteristic map (K1) defining the first TARGET speed (S1) of the oil separator on the basis of the engine operating state, - determining a maximum TARGET speed (S max ) of the oil separator on the basis of the first TARGET speed (S1) by means of the determination device such that the maximum TARGET speed (S max ) is at least as high as the first TARGET speed (S1), - determining a preferred TARGET speed (SB) based on the maximum TARGET speed (S max ) by means of the determination device such that the preferred TARGET speed (SM) is at most as great as the maximum TARGET speed (S max ), and - controlling an electric motor for driving the oil separator with the preferred TARGET speed (SB) by means of a control device , characterized in that an oil temperature (OT) of the internal combustion engine is identified by means of the identification device , a second TARGET speed (S2) of the oil separator being identified on the basis of the identified oil temperature (OT) and a second characteristic map (K2) being determined by means of the determination device , the second characteristic map (K2) defining the second TARGET speed (S2) of the oil separator on the basis of the oil temperature (OT), the maximum TARGET speed (S max ) of the oil separator being determined by means of the determination device additionally on the basis of the second TARGET speed (S2) such that the maximum TARGET speed (S max ) is at least as high as the second TARGET speed (S2). - identifying an engine operating state of the internal combustion engine by means of an identification device , the engine operating state being determined by an engine load (ML) and/or an engine speed (MD) of the internal combustion engine , - determining a first TARGET speed (S1) of the oil separator on the basis of the identified engine operating state and a first characteristic map (K1) by means of a determination device , the first characteristic map (K1) defining the first TARGET speed (S1) of the oil separator on the basis of the engine operating state, - determining a maximum TARGET speed (S max ) of the oil separator on the basis of the first TARGET speed (S1) by means of the determination device such that the maximum TARGET speed (S max ) is at least as high as the first TARGET speed (S1), - determining a preferred TARGET speed (SB) based on the maximum TARGET speed (S max ) by means of the determination device such that the preferred TARGET speed (SM) is at most as great as the maximum TARGET speed (S max ), and - controlling an electric motor for driving the oil separator with the preferred TARGET speed (SB) by means of a control device , <EOS>