GM Service Manual Online
For 1990-2009 cars only

Lower Intake Manifold Replacement L26

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
  5. Remove the exhaust gas recirculation (EGR) outlet pipe bolt (2) from the lower intake manifold.
  6. Remove the EGR outlet pipe (1) from the lower intake manifold.

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

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

  11. Object Number: 371022  Size: SH
  12. Remove the generator brace bracket bolts.
  13. Remove the generator brace bracket.

  14. Object Number: 190545  Size: SH
  15. Remove the lower intake manifold bolts.
  16. Remove the lower intake manifold.

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

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

  21. Object Number: 406012  Size: SH
  22. If replacing the lower intake manifold, remove the water outlet housing bolt, stud and the water outlet housing.
  23. If replacing the lower intake manifold, remove the ECT sensor.
  24. Inspect the flatness of the inlet flanges.
  25. Clean the intake manifold gasket mating surfaces.
  26. 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
  3. If removed, install the thermostat, the gasket, and the water outlet housing.
  4. Install the water outlet housing bolt and the stud.
  5. Tighten
    Tighten the bolt and the stud to 27 N·m (20 lb ft).


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

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

  10. 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.

  11. Install the lower intake manifold.
  12. Apply thread lock compound to the two hidden bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.

  13. Object Number: 44774  Size: SH
  14. Install the lower intake manifold bolts (1-12).
  15. Tighten
    Tighten the lower intake manifold bolts in sequence to 15 N·m (11 lb ft).


    Object Number: 371022  Size: SH
  16. Install the generator brace bracket.
  17. Install the generator brace bracket bolts.
  18. Tighten
    Tighten the bolts to 50 N·m (37 lb ft).


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

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

  22. Object Number: 911030  Size: SH
  23. Install the EGR outlet pipe (1) to the lower intake manifold.
  24. Install the EGR outlet pipe bolt (2) to the lower intake manifold.
  25. Tighten
    Tighten the bolt to 29 N·m (21 lb ft).


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

Lower Intake Manifold Replacement L32

Removal Procedure


    Object Number: 405984  Size: SH
  1. Drain the cooling system. Refer to Cooling System Draining and Filling .
  2. Remove the supercharger. Refer to Supercharger Replacement .
  3. Remove the radiator inlet hose from the water outlet housing. Refer to Radiator Inlet Hose Replacement .

  4. Object Number: 911030  Size: SH
  5. Remove the exhaust gas recirculation (EGR) outlet pipe bolt (2) from the lower intake manifold.
  6. Remove the EGR outlet pipe (1) from the lower intake manifold.
  7. Disconnect the engine coolant temperature (ECT) sensor electrical connector.

  8. Object Number: 97724  Size: SH
  9. Remove the lower intake manifold bolts.
  10. Remove the lower intake manifold. The coolant bypass tube will release from the intake manifold as the manifold is removed.
  11. Remove the lower intake manifold seals.
  12. Remove the lower intake manifold gaskets.
  13. If replacing the lower intake manifold, remove the water outlet housing and the thermostat.
  14. If replacing the lower intake manifold, remove the ECT sensor.
  15. Inspect the flatness of the inlet flanges.
  16. Clean the lower intake manifold gasket mating surfaces.
  17. Clean the intake manifold bolts and the bolt holes of the adhesive compound.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.

  1. If removed, install the ECT sensor.
  2. Tighten
    Tighten the ECT sensor to 25 N·m (18 lb ft).


    Object Number: 406012  Size: SH
  3. If removed, install the thermostat, the gasket, and the water outlet housing.
  4. Install the water outlet housing bolt and the stud.
  5. Tighten
    Tighten the bolt and the stud to 27 N·m (20 lb ft).


    Object Number: 97725  Size: MH
  6. Install the intake manifold gaskets.
  7. Apply sealer to the ends of the intake seals. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
  8. Install the lower intake manifold seals.

  9. Object Number: 97724  Size: SH
  10. Align the coolant bypass tube with the opening in the manifold. Install the lower intake manifold.
  11. Install the lower intake manifold bolts.
  12. Tighten
    Tighten the lower intake manifold bolts from the center to the outside in sequence to 15 N·m (11 lb ft).

  13. Connect the ECT sensor electrical connector.

  14. Object Number: 911030  Size: SH
  15. Install the EGR outlet pipe (1) to the lower intake manifold.
  16. Install the EGR outlet pipe bolt (2).
  17. Tighten
    Tighten the bolt to 29 N·m (21 lb ft).


    Object Number: 405984  Size: SH
  18. Install the radiator inlet hose to the water outlet housing. Refer to Radiator Inlet Hose Replacement .
  19. Install the supercharger. Refer to Supercharger Replacement .
  20. Fill the cooling system. Refer to Cooling System Draining and Filling .
  21. Inspect for fluid or vacuum leaks.