BMW 5 Series: Operating temperature
The positions of the rotary valve at engine operating temperature are shown by area C of the circuit diagram.
Operating temperature, Bx8TU engine
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 electric 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.
Maximum cooling requirement, Bx8TU engine
To provide maximum cooling at high dynamic loads and/or high ambient temperatures, the radiator connection is fully opened (100%) and the small coolant circuit 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.
