Mercedes-Benz OM 651 Service Manual page 31

Air supply
Intake port shutoff
The intake port shutoff (EKAS) function ensures the
best possible ratio between air mixing and air mass in
all engine load conditions and thus an optimal fill level.
This optimizes the exhaust characteristics and engine
output. The charge air manifold is made of plastic and
the flaps are made of metal.
In the charge air manifold, there is a permanently open
tangential intake port and a flap-controlled spiral
intake port for each cylinder. The flaps are connected
to each other by a shaft. The CDI control unit controls
the position of the flaps based on performance maps.
Charge air manifold
1 Actuator motor
2 Adjustment flap
3 Spiral intake port
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Introduction of New Generation of 4-Cylinder Inline Engines, OM 651
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– This printout will not be recorded by the update service. Status: 09 / 2008 –
When the engine switches from the partial load range
to the full load range, the flaps in the spiral intake
ports are opened according to performance maps.
In the event of a fault or if the supply voltage is inter-
rupted, the flaps in the spiral intake ports are mechan-
ically opened by the return springs.
4 Tangential intake port
5 Charge air manifold