Contents Cooling and lubrication Engine cooling 36 Engine lubrication and oil circuit 38 Oil pump 40 Coolant pump 41 Electrical and electronic systems Engine control unit 42 Glow system 43 Pneumatic system Vacuum control 44 Environmental protection Emission reduction 46 Service information New features 48 Special tools Engine 50 Abbreviations 55 Index 56 4 Introduction of New Generation of 4-Cylinder Inline Engines, OM 651 q – This printout will not be recorded by the update service. Status: 09 / 2008 –