GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Epica 🢒 Engine 🢒 Engine Controls - 2.5L (LBK) 🢒 Intake Manifold Replacement

Removal Procedure

    Caution: Refer to Battery Disconnect Caution in the Preface section.


    Object Number: 1375557 Size: SH
  1. Remove the fuel pump fuse.
  2. Start the engine and repeat cranking until the remaining fuel in the fuel line is all consumed.
  3. Disconnect the negative battery cable.
  4. Drain the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.

    5. Object Number: 1375558 Size: SH
  5. Remove the engine beautification cover retaining nut and engine beautification cover.
  6. Remove the air filter snorkel.

    7. Object Number: 1375163 Size: SH
  7. Remove the variable intake system (VIS) vacuum tank.

    8. Object Number: 1375560 Size: SH
  8. Remove the fuel pressure regulator.

    9. Object Number: 1375561 Size: SH
  9. Remove the breather hose.
  10. Remove the PCV vacuum hose.

    11. Object Number: 1375161 Size: SH
  11. Remove the air filter outlet hose.
  12. Remove the throttle body assembly. Refer to Throttle Body Assembly Replacement in Engine Controls-2.5L.

    13. Object Number: 1375345 Size: SH
  13. Disconnect the charcoal canister purge solenoid connector and hose.
  14. Disconnect the heated oxygen sensor (HO2S) connector.
  15. Disconnect the manifold absolute pressure (MAP) sensor connector.
  16. Disconnect the crankshaft position (CKP) sensor connector.

    17. Object Number: 1375564 Size: SH
  17. Disconnect the exhaust gas recirculation (EGR) solenoid connector.
  18. Disconnect the camshaft position (CMP) sensor connector.
  19. Remove the intake air temperature (IAT) sensor.
  20. Disconnect the ignition coil connector.
  21. Remove the vacuum hose on the brake booster.

    22. Object Number: 1375351 Size: SH
  22. Remove the EGR pipe from the intake manifold.
  23. Remove the engine coolant temperature (ECT) sensor.

    24. Object Number: 1375330 Size: SH
  24. Remove the wiring harness from the support bracket on the cylinder block.

    25. Object Number: 1375152 Size: SH
  25. Remove the intake manifold retaining nuts/bolts and the intake manifold.
  26. Remove the bolts on the intake manifold support bracket.
  27. Remove the intake manifold gaskets.
  28. Clean the contact surfaces between intake manifold and the cylinder head.

    29. Important: Remove the fuel rail after removing the intake manifold.

Installation Procedure

    Object Number: 1375572 Size: SH
  1. Discard used intake manifold gaskets and install new ones.

    2. Important: Install the intake manifold after installing the fuel rail.

  2. Install the intake manifold.

    3. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the intake manifold retaining nuts and bolts.

    4. Tighten

        • Tighten the 7 intake manifold retaining bolts to 12 N·m (106 lb in).
        • Tighten the 4 intake manifold retaining nuts to 12 N·m (106 lb in).
  4. Install the intake manifold support bracket.

    5. Tighten
    Tighten the 2 bolts on the intake manifold support bracket to 12 N·m (106 lb in).


    Object Number: 1375330 Size: SH
  5. Install the wiring harness to the supporting bracket on the cylinder block.
  6. Install the ECT sensor.

    7. Object Number: 1375365 Size: SH
  7. Install the EGR pipe to the intake manifold.
  8. Install the intake EGR pipe retaining bolts on the intake manifold.

    9. Tighten
    Tighten the intake EGR pipe retaining bolts to 10 N·m (89 lb in).


    Object Number: 1375311 Size: SH
  9. Install the vacuum hose to the brake booster.
  10. Connect the ignition coil connector.
  11. Install the IAT sensor.

    12. Tighten
    Tighten the IAT sensor to 25 N·m (18 lb in).

  12. Connect the CMP sensor connector.
  13. Connect the EGR solenoid connector.

    14. Object Number: 1375345 Size: SH
  14. Connect the CKP sensor connector.
  15. Connect the MAP sensor connector.
  16. Connect the HO2S connector.
  17. Connect the charcoal canister purge solenoid connector and hose.

    18. Object Number: 1375155 Size: SH
  18. Install the throttle body assembly. Refer to Throttle Body Assembly Replacement in Engine Controls-2.5L.

    19. Tighten
    Tighten the throttle body assembly retaining bolts to 13 N·m (115 lb in).


    Object Number: 1375561 Size: SH
  19. Install the PCV vacuum hose.
  20. Install the breather hose.

    21. Object Number: 1372465 Size: SH
  21. Install the fuel pressure regulator. Refer to Fuel Pressure Regulator Replacement in Engine Controls-2.5L.

    22. Tighten
    Tighten the fuel pressure regulator retaining bolts to 12 N·m (106 lb in).


    Object Number: 1375175 Size: SH
  22. Install the VIS vacuum tank. Refer to Intake Manifold Tuning Valve Vacuum Reservoir Replacement in Engine Controls-2.5L.

    23. Tighten
    Tighten the VIS vacuum tank retaining bolts to 8 N·m (71 lb in).


    Object Number: 1375651 Size: SH
  23. Install the air filter snorkel.

    24. Tighten
    Tighten the air filter snorkel retaining bolts to 6 N·m (53 lb in).


    Object Number: 1375656 Size: SH
  24. Install the engine beautification cover.

    25. Tighten
    Tighten the engine beautification retaining bolts to 10 N·m (89 lb in).

  25. Install the fuel pump fuse.
  26. Connect the negative battery cable.
  27. Refill the engine cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.