Intake Plenum, Z 32 SE Opel Vectra C

• The intake plenum (1) (intake module) replaces a large number of individual components. It is attached to the cylinder heads with only six bolts, via an intake flange (adapter).
• The main components are:
• Intake plenum (1) with switchover flaps Throttle valve module (5) Injectors (2) Fuel distributor rails Wiring harness Solenoid switchover valve Engine casing vent hose (4) Coolant hose to throttle valve pre-heating (6) Hose for tank vent valve (3)
• The weight has been reduced in comparison to previous intake devices by the use of die-cast magnesium.
• The positive output and torque values are achieved by the ability to switch between two different intake path lengths:
• Short: approx. 160 mm – power duct Long: approx. 550 mm – torque duct
• The two different intake path lengths are achieved via pneumatically-driven switchover units (one for each cylinder bank).
• Due to high pressure peaks in the intake ducts, high closing forces and high sealing efficiency is required for the flaps. A torque of approx. 10 Nm is present at the switchover shaft. This torque is generated by a toggle mechanism. The drive is by means of a vacuum unit, in each case.
• The required vacuum is provided via a solenoid switchover valve, from a vacuum reservoir integrated into the intake pipe. The switchover valve is actuated by the engine control unit, depending upon load and engine speed.

1. 1. Intake plenum cover
2. 2. Switchover units
3. 3. Intake pipe lower part and intake pipe upper part
4. 4. Throttle valve module
5. 5. Service valve
6. 6. Fuel feed line
7. 7. Wiring harness plug
8. 8. Vacuum hoses from solenoid switchover valve to the vacuum unit flap actuators
9. 9. Safety valve
10. 10. Solenoid switchover valve
11. 11. Vacuum units

1. 1. Vacuum hoses from solenoid switchover valve to the vacuum unit flap actuators
2. 2. Valve mushroom
3. 3. Flaps
4. 4. Vacuum reservoir
5. 5. Switchover shaft
6. 6. Fuel feed line to fuel distributor pipe connections
7. 7. Fuel distributor rails
8. 8. Fuel feed line
9. 9. Installation location for sealing sleeve

1. 1. Injectors
2. 2. Wiring harness
3. 3. Wiring harness plug
4. 4. Fuel feed line

Intake Flange (Adapter)

1. 1. Gaskets
2. 2. Intake flange, cylinder side
3. 3. Intake flange, intake plenum side

• Service:

• The intake plenum cover can be removed and installed up to three times. The spray-on gasket on the cover must be checked for damage after each removal. A new cover must be installed if the gasket is damaged.
• The intake flange can be removed and installed up to three times. The spray-on gaskets must be checked for damage after each removal. In the case of damage, the intake flange must be replaced.
• The bolts for the intake plenum cover are microencapsulated. The threads in the intake plenum must be cleaned after each removal of the cover. New microencapsulated bolts must be used for each installation.
• The vacuum reservoir has its own gasket. If the gasket is damaged, the vacuum reservoir must be replaced.
• Switchover shaft, flaps and vacuum actuating devices form a unit (switchover unit), which must not be disassembled. If the unit is damaged, it must be replaced completely.
• Sealing sleeves are installed between the vacuum reservoir and the intake plenum cover, which can be replaced individually, if required.
• The injectors can be replaced individually.
• In order to remove the fuel distributor rails, the union nuts must be loosened. They can be replaced individually for each cylinder bank.
• The solenoid switchover valves are available individually.
• The vacuum hoses are available cut to size.

Checking the Switchover Unit

Any play between switchover unit housing and the intake plenum is compensated by turning the flaps in the direction of closing. In this way, the greatest power reserve for the flap system is achieved.

The illustration shows the toggle mechanism behind the switchover unit cover.

1. Checking Closing of the Flap System

The check determines start of closing.

Staring at 200 mbar, the vacuum is slowly increased until the flap system closes automatically. The pressure must be between 200 and max. 400 mbar. The stroke of the diaphragm rod (1) is greater than 6 mm (in direction of arrow).

At this vacuum level, the toggle mechanism must not yet contact the safety stop.

2. Checking Power Reserve of the Flap System

Starting with the vacuum level applied in the 1st test and increasing the vacuum by 100 + 50 mbar, an additional stroke of the diaphragm rod (1) of at least: 1 mm (in direction of arrow) must be measurable.

3. Checking Safety Stop

For a further increase of the vacuum to at least 780 mbar to max. 850 mbar, no diaphragm stroke must be measurable.

At this vacuum level, the toggle mechanism contacts the safety stop (1).

Following removal of the vacuum, the flap system must open automatically.