Repair manual

Oil Circulation System
22
High Pressure Setting is Reached
Oil Pressure Regulation Valve N428 remains de-energized.
The force equilibrium between the control piston and
regulating spring is maintained by the higher oil pressure
(the effective piston surface area is smaller).
As engine speed increases, the cam lobe unit again
begins to move (as in the low pressure setting). The
change-over to the high pressure setting is registered by
O.3 Bar Oil Pressure Switch F22 (on the oil filter module).
In the high pressure setting, the switchable oil passage is
kept closed by Oil Pressure Regulation Valve N428.
Cam Lobe Unit at Stop
Cam
Lobe
Unit
Oil Pressure
Regulation
Valve N428
Pumped
Oil
Control
Piston
Regulating
Spring
Switchable
Pressure Port
(now pressure-less)
Engine
Speed [rpm]
Relative Oil
Pressure [bar]
Engine
Speed [rpm]
Cam
Lobe
Unit
Relative Oil
Pressure [bar]