A mechanical coolant pump for an internal combustion engine includes a pump rotor wheel comprising a blocking ring and rotor blades. The rotor blades are configured to pump a coolant radially outwardly. Variable pump stator blades are pivotably supported by a static blade holding ring at a first axial blade end. The variable pump stator blades are arranged radially outwardly of the pump rotor wheel. The blocking ring is arranged to partially overlap a second axial blade end.