BMW 3 Owners & Service Manuals

BMW 3: Operating temperature

The positions of the rotary valve at engine operating temperature are shown by area C of the heat management module circuit diagram.

Operating strategy
Operating temperature

The graphic shows control with the engine at operating temperature. The position of the rotary valve means that the cross-sections of the respective coolant lines are open to a greater or lesser extent depending on the coolant temperature. The coolant flows with a varying volumetric flow through the small coolant circuit, the large coolant circuit and the heater circuit. Depending on the load request, the crankcase's coolant connection is opened by the electrical Split Cooling valve, thus cooling the crankcase. Large engine operation ranges are covered with the crankcase coolant circuit closed.

Maximum cooling requirement

The maximum cooling requirement is shown at point E of the heat management module circuit diagram.

Operating strategy
Maximum cooling requirement

To provide maximum cooling at high dynamic loads and/or high ambient temperatures, the radiator connection is fully opened (100%) and the bypass line is completely closed . Additionally, the heater circuit is 90% closed to achieve the maximum cooling thanks to the maximum coolant volumetric flow through the large coolant circuit.


     Coolant pump

    The layout and function of the coolant pump have been revised and adapted to match the cooling concept of the B46TU/B48TU engines. Coolant pump Pressure relief valve closed (pressure <

     Exhaust System

    Exhaust turbocharger Exhaust turbocharger The exhaust turbocharger can be replaced individually and is exclusively made of steel. The boost charge pressure is still controlled by an electrical waste

     Fuel System

    The fuel system is made up of the fuel supply and fuel preparation systems. The fuel supply includes the fuel tank with all mounted parts and the fuel lines up to the engine compartment. The fuel p


     Chain drive - Crankshaft drive

    Features: Chain drive at the side of the engine emitting the forces. Single-part chain drive for driving the camshafts. Single sleeve-type chain 8 mm. Electric motor of the combined oil-vacuum pump via a separate chain. Plastic tensioning and guide rail. Hydraulic chain tensioner with sp

     Low coolant temperature

    When the coolant temperature is low, for example after driving off, or in all-electric driving, the electric changeover valve is activated by the Body Domain Controller (BDC). The electrical changeover valve blocks the supply from the coolant circuit of the combustion engine. The coolant is now p

    © 2019-2024 Copyright