New Generation N62 Engine
Chapter 3 P.3
Course Contents/Background Material
© BMW AG,
Service Training
Throttle valve
The throttle valve mounted on the N62 is not necessary for
engine load control. This is carried out by the intake valves'
variable lift adjustment. The tasks of the throttle valve are:
- Starting the engine:
During the starting procedure and when the engine is idling at
a temperature of between 0 ºC and 60 ºC, airflow is controlled
by the throttle valve.
If the engine is at operating temperature, it will be switched to
non-throttle mode approximately 60 seconds after it is started
up. In cold conditions, however, the engine is started with the
throttle valve fully opened, since this has a positive effect on
the starting characteristics.
- Ensuring a constant vacuum pressure of 50 mbar in the intake
pipe:
This vacuum pressure is needed to exhaust the blow-by gases
from the crankcase and the fuel vapours from the activated
charcoal filter.
- The emergency running function:
If the Valvetronic system should fail, the throttle valve imple-
ments the engine's emergency running function (conventional
load control).
Throttle valve structure
- Throttle-valve housing with throttle valve
- Throttle valve actuator
- Two throttle valve potentiometers (feedback signal is contra-
rotating)
