BMW 5 Series: Cold-start phase
Point A in the heat management module circuit diagram designates the cold start with an engine that has completely cooled down.
Cold-start phase, Bx8TU engine
In the cold-start phase, the coolant circulates exclusively via a bypass in the coolant pump. The rotary valve in the heat management module closes the coolant lines so that the excess pressure that builds up opens the pressure relief valve in the coolant pump (opening pressure 2.1 bar) and the coolant is recirculated in the coolant pump.
Because the coolant circuits through the exhaust turbocharger and the ventilation line of the cylinder head cannot be closed, a low volumetric flow is returned to the coolant pump here.
Warm-up phase
Area B in the circuit diagram for the heat management module shows the opening angle of the rotary valve in the warm-up phase.
Warm-up phase, Bx8TU engine
In the warm-up phase, the heat management module additionally opens the connection to the heating in addition to opening the bypass line. The coolant flows through the cylinder head, the exhaust turbocharger and the engine oil/coolant heat exchanger. The electric split cooling valve is closed; no coolant flows through the engine block (split cooling).
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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 operat
Coolant pump
The layout and function of the coolant pump have been revised and adapted to
match the cooling
concept of the Bx8 TU engines.
Coolant pump, Bx8TU engine
Pressure relief valve closed (pr
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Parking brake
Concept
The parking brake is used to prevent the vehicle
from rolling when it is parked.
Safety information
Warning
An unsecured vehicle can begin to move and
possibly roll away. There is a risk of accident.
Before exiting, secure the vehicle against rolling.
In order to ensure that the vehicle is
Chain track
Comparison between chain track of B58 engine and B58TU engine
Chain track, two-part timing chain drive B58 engine
Chain track, single-part timing chain drive B58TU engine
6-cylinder engine
Upper timing chain
Timing chain
Lower timing chain
Drive chain, oil vacuum pump
The way the combin
