The invention relates to a liquid cooling system (K) for an internal combustion engine (2) of a vehicle with a cylinder head (3) having as integrated exhaust manifold (7), wherein the cylinder head (3) has at least a first cooling chamber (5) for cooling areas adjoining a combustion chamber and at least a second cooling chamber (6) for cooling the exhaust manifold (7), wherein flows can pass through the first and second cooling chambers (5, 6) in parallel separately from one another. The cooling management can be improved in a simple manner if at least one oil cooler (14) and/or at least one vehicle heating element (15) is arranged in series with the second cooling chamber (6) in the cooling circuit (1).