Intake manifold — removal and installation (Opel Astra G)

Single-cylinder (SOHC) engines

1. Decompress the fuel system (Chapter 4A) and disconnect the battery from ground.

2. Remove the drive belt. Drain the coolant.

3. Remove the air filter and intake duct.

4. Remove the upper section of the throttle body by unscrewing the screws and disconnecting the hoses.

5. Mark and disconnect the wire connectors that run near the intake manifold. Remove the wires from the brackets and clamps.

6. Unscrew the bolts securing the generator bracket to the manifold. Move the generator with the bracket to the side.

7. Disconnect the throttle cable and remove the cable bracket from the manifold (see photo).



8. Disconnect all hoses from the manifold and throttle body (see photo), unscrew the nuts and remove the manifold.



9. When assembling, replace the manifold mounting nuts, as well as all the gaskets and seals of the disassembled connections. Tighten the manifold nuts evenly and gradually in a diagonal order.

Twin-shaft engines 1.4 and 1.6 l

10. Remove the upper engine cover by unscrewing the screws and removing the oil filler plug.

11. Remove the air filter and air duct.

12. Move the generator drive belt tensioner away and remove the belt.

13. Unscrew the generator bracket mounting bolts on the right side of the manifold.

14. Loosen the lower generator mounting bolt and move the generator to the side by turning it (see photo).



15. Remove the manifold stand (see photo).



16. Remove the injectors with the fuel distributor.

17. Disconnect the throttle cable from the throttle body.

18. Mark and disconnect all wires and hoses from the manifold and throttle body (see photo).



19. Unscrew 5 bolts and remove the manifold. To remove the manifold flange, disconnect the hose (see photo) and unscrew 9 nuts. Further disassembly of the manifold is highly discouraged.







20. Installation is performed in the reverse order. Replace all gaskets and seals of the disassembled connections. Tighten the manifold and flange nuts and bolts evenly and gradually in a diagonal order.

Engines 1.8 and 2.0 l

21. Remove the alternator belt, decompress the fuel system and disconnect the battery from ground.

22. Remove the upper engine cover by unscrewing the screws and removing the oil filler cap

23. Loosen the clamps and disconnect the air duct with the air flow meter from the throttle pipe and air filter. On Zafira models, this will require removing the engine compartment seal, the air vent panels under the windshield and the cover above the engine compartment bulkhead.

24. Mark and disconnect all accessible wires, hoses and cables from the intake manifold and throttle body (see photo). Remove the cable brackets from the throttle body.









25. Disconnect the generator bracket from the manifold and move the generator to the side together with the bracket (see photo).



26. Remove the manifold stand by unscrewing the bolts (see photo).





27. Disconnect the fuel lines and hoses from the fuel distributor. Remove the fuel distributor together with the injectors and the wiring box and connectors (see photo).



28. Disconnect the brake booster hose from the manifold (see photo) and hoses from the heater.



29. On 1.8L models, remove the engine processor unit (see above), on 2.0L models, disconnect the pipe from the clutch master cylinder



30. Remove the manifold after completing the final steps (see photo). Further disassembly of the manifold is not permitted.







31. Installation is performed in the reverse order. Replace the manifold mounting bolts, all gaskets and seals of the disassembled connections. Tighten the manifold bolts evenly and gradually in a diagonal order. Remove air from the clutch hydraulic drive (1.8 l), adjust the cables and belt tension.