Opel Corsa B 1993–2000 Service and Repair Manual: Air cleaner housing - removal and refitting

Removal

1. Remove the centre retaining nut or bolt or the three screws from the air cleaner cover.

2. Lift the air cleaner off the carburettor, disengaging the hot air pick-up from the manifold shroud (where necessary), together with the breather and vacuum hoses (see illustrations).

Hot air pick-up tube (arrowed) engages with air cleaner

Air cleaner vacuum hose connection

Air cleaner hose connection

Refitting

3. Refit by reversing the removal operations, making sure that the gasket or sealing ring is in place on the carburettor.

Air cleaner air temperature control system - general information

1.2 litre models

1 Inlet air pre-heating is controlled manually by a flap valve located in the side of air cleaner casing. The valve can be set in any one of three positions according to seasonal operating temperature as shown in the following table.

• Summer position - above 10ºC
• Intermediate position - 10ºC to -5ºC
• Winter position - below -5ºC

2. In terms of fuel economy the engine will run most efficiently with the valve set in the summer position and least efficiently in the winter position. Providing the engine is running smoothly, and accelerates evenly, the summer position may be retained down to 0ºC. If roughness or hesitation occurs, move the flap valve to the next position.

3. The three positions are shown on the air cleaner cover. In the winter position only hot air from the hot air box on the exhaust manifold enters the air cleaner. In the summer position only cold from the air cleaner inlet spout enters. In the intermediate position a blended supply from both sources enters the air cleaner.

1.3, 1.4 and 1.6 litre models

4. A thermostatically controlled air cleaner is used to regulate the temperature of the air entering the carburettor according to ambient temperatures and engine load. The air cleaner has two sources of supply, through the normal inlet spout (cold air) or from a hot air box mounted on the exhaust manifold (hot air).

5. The airflow through the air cleaner is controlled by a flap valve in the air cleaner spout, which covers or exposes the hot or cold air ports according to temperature and manifold vacuum.

6. A vacuum motor operates the flap valve and holds it fully open when the temperature in the air cleaner is below a predetermined level. As the air inlet temperature rises the vacuum motor opens or closes the flap valve dependent entirely on manifold vacuum. Thus, during light or constant throttle applications, the flap valve will remain open, supplying the carburettor with hot air, and will close under heavy throttle application so that only cold air enters the carburettor.

7. As the temperature in the air cleaner rises further the vacuum motor closes the flap valve therefore allowing only cold air to enter the carburettor under all operating conditions.

8. The vacuum motor is operated by vacuum created in the inlet manifold and is controlled by a temperature sensing unit located inside the air cleaner.