Patent ID: 7237513

Claim:
An internal combustion engine ( 6 ) for a motor vehicle, comprising a cylinder head ( 7 ) with a coolant inlet port ( 4 ) and a coolant return flow port ( 10 ), an engine block ( 8 ) with a coolant inlet port ( 5 ) and a coolant return flow port ( 10 ) common to the cylinder head ( 7 ) and the engine block ( 8 ), a main coolant pump ( 1 ) having an intake side which is connected to the coolant return flow port ( 10 ) and a pressure side which is connected to a first flow control unit ( 3 ) for controlling admission of coolant to the inlet port ( 4 ) of the cylinder head ( 7 ) and the inlet port ( 5 ) of the engine block ( 8 ), the main coolant pump ( 1 ) being switchable on and off depending on the cooling requirement for the cylinder head ( 7 ) and the engine block ( 8 ), a second flow control unit ( 17 ) disposed in a coolant return line of the internal combustion engine ( 6 ) for returning the coolant, depending on the temperature, to the intake of the main coolant pump ( 1 ) selectively either in a large circuit ( 20 ) which includes an air/fluid cooler ( 21 ) or in a small circuit ( 18 ) which bypasses the air/fluid cooler ( 21 ), a heating circuit line ( 12 ) which is branched off from a coolant return flow line of the internal combustion engine ( 6 ) for conducting part of the coolant back to the main coolant pump ( 1 ) bypassing the second flow control unit ( 17 ), and an additional electric coolant pump ( 16 ) arranged in the heating circuit line ( 12 ).