New Generation N62 Engine
Chapter 3 P.84
Course Contents/Background Material
© BMW AG,
Service Training
- Pressure control
The oil pressure control valve in the oil pump has two functions:
1. It switches off the second level (impeller) of the oil pump in a
short circuit from about 2 bar.
The second level is only active in the lower speed range. This
is to ensure that there is always sufficient oil pressure for the
VANOS units even at high oil temperatures and low speeds.
The oil pump's power consumption is reduced by switching off
the second level.
2. It monitors the required oil pressure for the engine. The piston
in the control valve is moved by a spring against the engine
control pressure which is returning from the engine.
This means that precise monitoring of the actual oil pressure in
the engine is possible.
A separate pressure relief valve in the oil pump automatically
switches off at the maximum pressure of approximately 15 bar.
This prevents damage in the oil pump, especially at low oil
temperatures.
