Subaru Coupes/Sedans/Wagons 1985-1996 Repair Guide

Intake Manifold

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REMOVAL & INSTALLATION




CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

1.2L Engine

See Figures 1 and 2

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Fig. Fig. 1: Intake and exhaust manifold assembly-1.2L carbureted engine



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Fig. Fig. 2: Intake and exhaust manifold assembly-1.2L fuel injected engine

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system into a suitable container.
  4.  
  5. Remove the air cleaner assembly.
  6.  
  7. Tag and disconnect the upper radiator hose and heater hose from the intake manifold.
  8.  
  9. Disconnect the electrical harnesses and ground straps from the intake manifold.
  10.  
  11. Disconnect the accelerator linkage from the carburetor or throttle body assembly.
  12.  
  13. Tag and disconnect all the vacuum lines from the intake manifold, carburetor or throttle body.
  14.  
  15. Remove the air suction manifold pipe.
  16.  
  17. Remove the intake manifold mounting bolts.
  18.  
  19. Remove the intake manifold assembly.
  20.  
  21. Remove all gasket material from both mating surfaces.
  22.  

To install:
  1. Position the intake manifold on the engine using a new gasket, and loosely install the intake manifold bolts. With all the bolts installed, tighten them (starting from the center and moving outward) to 14-22 ft. lbs. (20-29 Nm).
  2.  
  3. Install the air suction manifold pipe.
  4.  
  5. Connect all the vacuum lines to the carburetor or throttle body and intake manifold.
  6.  
  7. Connect the accelerator cable to the carburetor or throttle body.
  8.  
  9. Connect the electrical harnesses to the intake manifold.
  10.  
  11. Connect the upper radiator and heater hose to the intake manifold.
  12.  
  13. Install the air cleaner assembly.
  14.  
  15. Refill the cooling system.
  16.  
  17. Connect the negative battery cable.
  18.  
  19. Start the vehicle and check for any sucking noise indicating a leak.
  20.  

1.6L and 1.8L Engines

See Figures 3, 4 and 5

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Fig. Fig. 3: Intake manifold assembly-1.6L and 1.8L carburetor engine



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Fig. Fig. 4: Intake manifold assembly-1.8L single port fuel injected engine



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Fig. Fig. 5: Intake manifold assembly-1.8L multi-port fuel injected engine

  1. Relieve the fuel system pressure.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Disconnect the fuel lines.
  6.  
  7. Drain the cooling system into a suitable container. Remove the radiator hoses.
  8.  
  9. On turbocharged models, remove the air duct with the airflow meter attached. On all other models, remove the air duct.
  10.  
  11. On turbocharged models, remove the turbo cooling hose and turbocharger.
  12.  
  13. Remove the front exhaust pipe from the cylinder head as required.
  14.  
  15. Tag and disconnect the distributor high tension wires, then matchmark and remove the distributor.
  16.  
  17. Label and disconnect all applicable vacuum hoses.
  18.  
  19. Remove the alternator, if needed for additional working space.
  20.  
  21. Remove the silencers and silencer hoses. Remove the air cleaner assembly.
  22.  
  23. Remove the air suction valves and hoses.
  24.  
  25. Remove the EGR cover and EGR pipe.
  26.  
  27. Remove the PCV valve and blow-by hoses.
  28.  
  29. Label and disconnect all applicable electrical harnesses.
  30.  
  31. Disconnect the accelerator cable.
  32.  
  33. Remove the intake manifold bolts and carefully lift the intake manifold off the engine.
  34.  
  35. Clean all gasket material from the mating surfaces.
  36.  

To install:
  1. Use a straightedge feeler gauge to inspect the intake manifold for flatness. Distortion should not exceed 0.020 in. (0.5mm).
  2.  
  3. Install the intake manifold using new gaskets, and secure in place with the mounting bolts. Tighten the bolts to 13-16 ft. lbs. (18-22 Nm).
  4.  
  5. Inspect all electrical connectors for damage and replace as necessary. Attach all electrical connectors.
  6.  
  7. Install the PCV valve and hoses. Install the EGR cover and pipe, and tighten bolts to 23-27 ft. lbs. (31-37 Nm). Install the air suction valve and hoses.
  8.  
  9. Install the silencers and hoses. Install the alternator if removed.
  10.  
  11. Inspect all vacuum lines for damage and replace as necessary. Install all vacuum lines.
  12.  
  13. On turbocharged models, install the turbo cooling hose and turbocharger. Install the front exhaust pipe from the cylinder head if removed.
  14.  
  15. On turbocharged models, install the air duct with the airflow meter. On all other models, install the air duct.
  16.  
  17. Install the distributor, if removed. Connect all distributor high tension wires.
  18.  
  19. Install the radiator hose and fill the cooling system.
  20.  
  21. Connect all fuel lines and install the air cleaner assembly.
  22.  
  23. Connect the negative battery cable, start the engine and allow it to reach operating temperature. Check for leaks. Test drive the vehicle.
  24.  

2.2L Engines

See Figures 6, 7, 8 and 9

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Fig. Fig. 6: Intake manifold assembly-2.2L engine



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Fig. Fig. 7: Loosen and remove the intake manifold retainer bolts-2.2L engine shown



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Fig. Fig. 8: Carefully lift off the intake manifold assembly



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Fig. Fig. 9: Remove and discard the intake manifold gaskets

  1. Release the fuel system pressure.
  2.  
  3. Disconnect the negative battery cable and remove the engine cover.
  4.  
  5. Drain the cooling system into a suitable container.
  6.  
  7. Remove the accessary drive belt(s).
  8.  
  9. Remove power steering pump and or, alternator for added clearance.
  10.  
  11. Label and disconnect all electrical harnesses leading to the intake manifold.
  12.  
  13. Label and disconnect all vacuum hoses leading to the intake manifold. Disconnect the PCV and blow-by hoses.
  14.  
  15. Label and disconnect the ignition high tension wires at the spark plugs and lay them aside.
  16.  
  17. Remove the connector bracket attaching bolt.
  18.  
  19. Remove the crank angle sensor and cam angle sensor.
  20.  
  21. Disconnect the oil pressure switch connector.
  22.  
  23. Remove the knock sensor.
  24.  
  25. Disconnect the air intake duct.
  26.  
  27. On turbocharged models, disconnect the turbo from the intake manifold and remove.
  28.  
  29. Disconnect the fuel supply lines and accelerator linkage.
  30.  
  31. Remove the intake manifold bolts and remove the intake manifold and discard the gaskets.
  32.  
  33. Remove the water pipe.
  34.  
  35. Clean all gasket material from both mating surfaces.
  36.  

To install:
  1. Use a straightedge and a feeler gauge to inspect the intake manifold for flatness. Distortion should not exceed 0.020 in. (0.5mm).
  2.  
  3. Install the intake manifold and secure in place with retainer bolts. Tighten the short bolts to 21-25 ft. lbs. (28-34 Nm); the long bolts to 4-5 ft. lbs. (6-7 Nm).
  4.  
  5. Install the fuel lines and accelerator linkage.
  6.  
  7. Install the turbocharger assembly, if equipped.
  8.  
  9. Install the air intake duct.
  10.  
  11. Install the knock sensor.
  12.  
  13. Connect the oil pressure switch electrical connector.
  14.  
  15. Clean the crank and cam angle sensors with compressed air and install them.
  16.  
  17. Install the connector bracket bolt.
  18.  
  19. Check the ignition high tension wires for damage and install on the spark plugs.
  20.  
  21. Check all vacuum lines for deterioration and replace as necessary. Install the vacuum lines.
  22.  
  23. Check all electrical connectors for damage and replace as necessary. Install the electrical connectors.
  24.  
  25. Install the PCV valve and blow-by hose.
  26.  
  27. Install the power steering pump and alternator if removed.
  28.  
  29. Install the water pipes and fill the cooling system.
  30.  
  31. Install the engine cover.
  32.  
  33. Start the engine and allow it to reach operating temperature. Check for leaks and test drive the vehicle.
  34.  

2.5L Engine

CAUTION
Fuel injection systems remain under pressure after the engine has been turned OFF. Properly relieve fuel pressure before disconnecting any fuel lines. Failure to do so may result in fire or personal injury.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system into a suitable container.
  4.  
  5. Remove the air intake duct, air cleaner upper cover and the air cleaner element.
  6.  
  7. Properly release the fuel pressure.
  8.  
  9. Disconnect the accelerator cable and the cruise control cable, if equipped.
  10.  
  11. Disconnect the ground cable from the intake manifold.
  12.  
  13. Disconnect the wiring harness from the throttle position sensor, fuel injectors, idle air control solenoid valve, purge control solenoid valve, and the exhaust gas recirculation solenoid valve.
  14.  
  15. Disconnect the air bypass hose from the idle air control solenoid valve.
  16.  
  17. Remove the idle air control solenoid valve from the intake manifold.
  18.  
  19. Disconnect the engine coolant hoses from the throttle body.
  20.  
  21. Remove the throttle body from the intake manifold and discard the gasket.
  22.  
  23. Disconnect the fuel hoses from the fuel pipes.
  24.  
  25. Disconnect the EGR and the purge control solenoid valves.
  26.  
  27. Disconnect the wiring harness from the knock sensor, camshaft position sensor, crankshaft position sensor and the oil pressure switch.
  28.  
  29. Remove the intake manifold mounting bolts. Remove the manifold and discard the gaskets.
  30.  

The intake manifold sits on pins that protrude from the cylinder heads. Be sure the pins remain in the cylinder heads.

To install:
  1. Using new gaskets, install the manifold to the engine. Tighten the mounting bolts to 19 ft. lbs. (26 Nm).
  2.  
  3. Connect the wiring to the knock sensor, camshaft position sensor, crankshaft position sensor and the oil pressure switch.
  4.  
  5. Connect the EGR and the purge control solenoid valves.
  6.  
  7. Connect the fuel hoses to the fuel pipes. Be sure to secure the hoses with new clamps.
  8.  
  9. Using new gaskets, install the throttle body to the intake manifold. Tighten the retaining bolts to 16 ft. lbs. (22 Nm).
  10.  
  11. Using new clamps, connect the engine coolant hoses to the throttle body.
  12.  
  13. Using a new gasket, install the idle air control solenoid valve to the intake manifold. Tighten the retaining bolts to 57 inch lbs. (6.4 Nm).
  14.  
  15. Connect the air bypass hose to the idle air control solenoid valve.
  16.  
  17. Connect the wiring harness to the throttle position sensor, fuel injectors, idle air control solenoid valve, purge control solenoid valve and the exhaust gas recirculation solenoid valve.
  18.  
  19. Connect the ground cable to the intake manifold.
  20.  
  21. Connect and adjust the accelerator cable and the cruise control cable.
  22.  
  23. Install the air cleaner assembly.
  24.  
  25. Connect the negative battery cable and refill the cooling system. Start the engine, and bleed the cooling system. Check for leaks.
  26.  

2.7L Engine

See Figure 10

Click image to see an enlarged view

Fig. Fig. 10: Intake manifold assembly-2.7L engine

  1. Relieve the fuel system pressure.
  2.  
  3. Disconnect and cap the fuel lines.
  4.  
  5. Disconnect the negative battery cable.
  6.  
  7. Remove the air duct.
  8.  
  9. Tag and remove the ignition wires. remove the distributor from the engine assembly.
  10.  
  11. Remove the alternator.
  12.  
  13. Tag and remove all electrical connectors from the intake manifold and throttle body assembly.
  14.  
  15. Tag and remove all vacuum hoses from the intake manifold and throttle body.
  16.  
  17. Remove the EGR cover and pipe.
  18.  
  19. Disconnect the accelerator linkage.
  20.  
  21. Remove the intake manifold mounting bolts, then remove the intake manifold and gaskets.
  22.  

To install:
  1. Clean the gasket mating surfaces thoroughly.
  2.  
  3. Using a straightedge and a feeler gauge, inspect the intake manifold for flatness. Distortion should not exceed 0.020 in. (0.5mm).
  4.  
  5. Install the intake manifold using new gaskets and tighten the mounting bolts to 15 ft. lbs. (20 Nm).
  6.  
  7. Connect the fuel lines.
  8.  
  9. Install the EGR pipe and tighten to 25 ft. lbs. (34 Nm). Install the EGR cover.
  10.  
  11. Connect the vacuum lines to the intake manifold and throttle body.
  12.  
  13. Connect the electrical connectors to the intake manifold and throttle body.
  14.  
  15. Install the alternator.
  16.  
  17. Install the distributor and connect the ignition wires.
  18.  
  19. Install the air duct.
  20.  
  21. Connect the negative battery cable.
  22.  
  23. Start the engine and allow it to reach operating temperature. Check for leaks and test drive the vehicle.
  24.  

3.3L Engine

See Figure 11

Click image to see an enlarged view

Fig. Fig. 11: Intake manifold assembly-3.3L engine


CAUTION
Fuel injection systems remain under pressure after the engine has been turned OFF. Properly relieve fuel pressure before disconnecting any fuel lines. Failure to do so may result in fire or personal injury.

  1. Relieve the fuel system pressure.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the collector cover.
  6.  
  7. Disconnect the accelerator cable and cruise control cable from the throttle lever, if equipped.
  8.  
  9. Remove the air intake ducts.
  10.  
  11. Disconnect the electrical harnesses from the intake manifold sensors and brackets.
  12.  
  13. Detach the electrical connector from the auxiliary air control valve.
  14.  
  15. Disconnect and cap the two coolant hoses from the underside of the throttle body.
  16.  
  17. Disconnect the auxiliary air control valve hose from the throttle body.
  18.  
  19. Disconnect the PCV hose.
  20.  
  21. Remove the blow-by hose from the cylinder head cover.
  22.  
  23. Disconnect the EGR control hoses from the intake manifold.
  24.  
  25. Remove the EGR pipe and cover.
  26.  
  27. Disconnect the power steering pump electrical harness
  28.  
  29. Disconnect the power brake booster vacuum hose.
  30.  
  31. Disconnect and cap the fuel lines from the fuel pipes.
  32.  
  33. Remove the drive belt cover and drive belts.
  34.  
  35. Unfasten the electrical connections from the alternator.
  36.  
  37. Remove the alternator. Refer to Engine Electrical for removal and installation steps.
  38.  
  39. Remove the A/C compressor mounting bolts and position the A/C compressor aside with the refrigerant lines attached.
  40.  
  41. Remove the intake manifold mounting bolts.
  42.  
  43. Remove the intake manifold.
  44.  
  45. Clean all gasket material from both mating surfaces.
  46.  

To install:
  1. Install the intake manifold using new gaskets. Tighten the intake manifold bolts to 18 ft. lbs. (24 Nm).
  2.  
  3. Install the A/C compressor.
  4.  
  5. Install the alternator and connect the electrical harnesses.
  6.  
  7. Install the drive belts and tension as necessary. Install the drive belt cover.
  8.  
  9. Connect the fuel lines to the fuel pipes.
  10.  
  11. Connect the vacuum line to the power booster.
  12.  
  13. Connect the electrical harnesses to the power steering pump.
  14.  
  15. Install the EGR pipe and cover and connect the EGR control hoses to the intake manifold.
  16.  
  17. Install the blow by hose to the cylinder head cover.
  18.  
  19. Connect the PCV hose.
  20.  
  21. Connect the auxiliary air control valve hose to the throttle body.
  22.  
  23. Connect the coolant hoses to the underside of the throttle body.
  24.  
  25. Attach the electrical connector to the auxiliary air control valve.
  26.  
  27. Connect the electrical harness to the intake manifold bracket.
  28.  
  29. Fasten the electrical connectors from the intake manifold sensors.
  30.  
  31. Install the air intake ducts.
  32.  
  33. Connect the accelerator cable and cruise control cable from the throttle lever.
  34.  
  35. Install the collector cover.
  36.  
  37. Connect the negative battery cable.
  38.  
  39. Pressurize the fuel system and check for leaks.
  40.  

 
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