GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2008 🢒 LaCrosse 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Lower Intake Manifold Replacement

Removal Procedure

    Object Number: 326960 Size: SH

    Notice: The two bolts which fasten the lower intake manifold to the cylinder head are accessible only after the upper intake is removed. The bolts are located in the right front and left rear corners of the lower intake manifold. Remove the upper intake manifold to service the lower intake.

  1. Remove the upper intake manifold. Refer to Upper Intake Manifold Replacement .
  2. Remove the generator brace. Refer to Generator Brace Replacement .
  3. Remove the drive belt tensioner with the heater water bypass inlet pipe. Refer to Drive Belt Tensioner Replacement .

    4. Object Number: 911030 Size: SH
  4. Remove the exhaust gas recirculation (EGR) outlet pipe bolt (2) from the lower intake manifold.
  5. Remove the EGR outlet pipe (1) from the lower intake manifold.

    6. Object Number: 405984 Size: SH
  6. Remove the radiator inlet hose from the water outlet housing. Refer to Radiator Inlet Hose Replacement .

    7. Object Number: 406011 Size: SH
  7. Disconnect the engine coolant temperature (ECT) sensor electrical connector.

    8. Object Number: 371022 Size: SH
  8. Remove the generator brace bracket bolts.
  9. Remove the generator brace bracket.

    10. Object Number: 190545 Size: SH
  10. Remove the lower intake manifold bolts.
  11. Remove the lower intake manifold.

    12. Object Number: 153573 Size: SH
  12. Remove the lower intake manifold seals.

    13. Object Number: 153574 Size: SH
  13. Remove the lower intake manifold gaskets.

    14. Object Number: 406012 Size: SH
  14. If replacing the lower intake manifold, remove the water outlet housing bolt, stud and the water outlet housing.
  15. If replacing the lower intake manifold, remove the ECT sensor.
  16. Inspect the flatness of the inlet flanges.
  17. Clean the intake manifold gasket mating surfaces.
  18. Clean the intake manifold bolts and bolt holes of adhesive compound.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.

  1. If removed, install the ECT sensor.

    2. Tighten
    Tighten the sensor to 25 N·m (18 lb ft).


    Object Number: 406012 Size: SH
  2. If removed, install the thermostat, the gasket, and the water outlet housing.
  3. Install the water outlet housing bolt and the stud.

    4. Tighten
    Tighten the bolt and the stud to 27 N·m (20 lb ft).


    Object Number: 153574 Size: SH
  4. Install the lower intake manifold gaskets.

    5. Object Number: 153573 Size: SH
  5. Apply sealer to the ends of the intake manifold seals. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
  6. Install the lower intake manifold seals.

    7. Object Number: 190545 Size: SH

    Notice: The two bolts which fasten the lower intake manifold to the cylinder head are accessible only after the upper intake is removed. The bolts are located in the right front and left rear corners of the lower intake manifold. Remove the upper intake manifold to service the lower intake.

  7. Install the lower intake manifold.
  8. Apply threadlock compound to the two hidden bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.

    9. Object Number: 44774 Size: SH
  9. Install the lower intake manifold bolts (1-12).

    10. Tighten
    Tighten the lower intake manifold bolts in sequence to 15 N·m (11 lb ft).


    Object Number: 371022 Size: SH
  10. Install the generator brace bracket.
  11. Install the generator brace bracket bolts.

    12. Tighten
    Tighten the bolts to 50 N·m (37 lb ft).


    Object Number: 406011 Size: SH
  12. Connect the ECT sensor electrical connector.

    13. Object Number: 405984 Size: SH
  13. Install the radiator inlet hose to the water outlet housing. Refer to Radiator Inlet Hose Replacement .

    14. Object Number: 911030 Size: SH
  14. Install the EGR outlet pipe (1) to the lower intake manifold.
  15. Install the EGR outlet pipe bolt (2) to the lower intake manifold.

    16. Tighten
    Tighten the bolt to 29 N·m (21 lb ft).


    Object Number: 326960 Size: SH
  16. Install the drive belt tensioner. Refer to Drive Belt Tensioner Replacement .
  17. Install the generator brace. Refer to Generator Brace Replacement .
  18. Install the upper intake manifold. Refer to Upper Intake Manifold Replacement .
  19. Inspect for fluid or vacuum leaks.