Intake Manifold Flaps

Intake Manifold Flaps

The engine on the Cayenne S Hybrid uses intake manifold flaps to improve the internal mixture formation. They are located in an intermediate flange between the air-charging module and cylinder head.







NOTE: When the intermediate flange is assembled, the intake manifold flaps must be set to power position (intake duct open).

Valve for intake manifold flap







The intake manifold flaps, which are secured on a common shaft, are actuated by a vacuum unit. The required vacuum is applied by the valve for the intake manifold flap. The engine control unit actuates the valve for the intake manifold flap according to the map.

Effects in the event of failure

No vacuum is applied if an intake manifold valve is not actuated or is faulty. In this state, the intake manifold flaps close the duct in the cylinder head via the spring force of the vacuum unit. The engine power is thus reduced.

Potentiometer for intake manifold flaps

Two sensors monitor the position of the intake manifold flaps:
- Cylinder bank 1: Potentiometer for intake manifold flap 1
- Cylinder bank 2: Potentiometer for intake manifold flap 2

The sensors are integrated directly in the flange of the vacuum unit. They are contactless torque angle sensors, which operate according to the Hall sender principle. The sensor electronics generate a voltage signal that is evaluated by the engine control unit.







Signal utilization

The signal monitors the position and is used for diagnostic purposes.

Effects in the event of signal failure

The position is no longer detected correctly. A diagnosis is no longer possible. The component is relevant to OBD, which means that the Check Engine warning light (MIL) switches on in the event of a failure.

Sound insulation of the supercharger

One other objective during the development of the engine was to minimize the noise generated by the supercharger. This objective was successfully achieved by making modifications to the housing design. A multilayer damping plate acts on the gas discharge vent on the supercharger. Additional measures in the intake area also make a contribution to reducing noise (see figure). Other sound insulation features include insulating mats positioned under the air-charging module.







NOTE: Helmholtz resonator is used to reduce the noise levels (in this instance) by the use of sound deadening material, or possibly slots or openings within the unit.

Insulating mats







Several sound insulation mats are located between the air-charging module and the cylinder head or block. These mats provide sound insulation for the area under the supercharger. Two small insulating inserts are located on the back of the air-charging module.







Other insulating mats are located under the air-charging module in the inner V of the engine. While a larger mat is positioned between the two intake manifolds, two narrower insulating mats are inserted laterally between the intake manifolds and the cylinder heads.