GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 CTS 🢒 Preface 🢒 Cautions and Notices 🢒 Upper Intake Manifold Replacement

Removal Procedure

    Object Number: 1305320 Size: SH
  1. Turn the ignition OFF.
  2. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
  3. Remove the air inlet duct. Refer to Air Cleaner Inlet Duct Replacement .
  4. Disconnect the brake booster vacuum hose from the intake manifold.

    5. Object Number: 887878 Size: SH
  5. Disconnect the purge solenoid valve electrical connector.

    6. Object Number: 1348201 Size: SH
  6. Disconnect the purge line (3) from the purge solenoid valve.

    7. Object Number: 1285256 Size: SH
  7. Remove the wiring harness retainer.

    8. Object Number: 887881 Size: SH
  8. Disconnect the throttle body electrical connector.

    9. Object Number: 1522522 Size: SH
  9. Remove the harness clip from the brace/bracket.
  10. Remove the upper intake manifold brace stud (1), bolt (2), and brace.
  11. Disconnect the positive crankcase valve (PCV) hose from the right bank camshaft cover.

    12. Object Number: 945437 Size: SH
  12. Disconnect the barometric pressure sensor electrical connector.

    13. Object Number: 945390 Size: SH
  13. Disconnect the intake manifold runner control solenoid electrical connector.

    14. Object Number: 887871 Size: SH
  14. Disconnect the left bank ignition coil harness electrical connector.
  15. Remove the PCV line from the clip on the harness bracket.

    16. Object Number: 1318829 Size: SH
  16. Remove the left bank ignition coil wiring harness from the bracket.
  17. Remove the injector harness bracket bolt and bracket.

    18. Object Number: 1285188 Size: SH
  18. Remove the upper intake manifold bolts. Some deflection of the cowl panel may be necessary to extract the right rear bolt.
  19. Remove the upper intake manifold with the throttle body.
  20. If the upper intake manifold is being replaced, disassemble the intake manifold. Refer to Intake Manifold Disassemble .
  21. Clean and inspect the intake manifold. Refer to Intake Manifold Cleaning and Inspection .

Installation Procedure
  1. If the upper intake manifold is being replaced, assemble the intake manifold. Refer to Intake Manifold Assemble .

    2. Object Number: 1285188 Size: SH
  2. Install a NEW upper intake manifold gasket.
  3. Install the upper intake manifold.

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

    Important: Tighten the intake manifold bolts in a circular pattern starting at the center (long bolts) and moving outward.

  4. Install the upper intake manifold bolts.

    5. Tighten
    Tighten the bolts to 23 N·m (17 lb ft).


    Object Number: 1318829 Size: SH
  5. Install the injector harness bracket and bolt.

    6. Tighten
    Tighten the bolt to 10 N·m (89 lb in).

  6. Install the left bank ignition coil wiring harness to the bracket.

    7. Object Number: 887871 Size: SH
  7. Install the PCV line to the clip on the harness bracket.
  8. Connect the left bank ignition coil harness electrical connector.

    9. Object Number: 945437 Size: SH
  9. Connect the BARO sensor electrical connector.

    10. Object Number: 945390 Size: SH
  10. Connect the intake manifold runner control solenoid electrical connector.
  11. Connect the PCV hose to the right bank camshaft cover.

    12. Object Number: 1522522 Size: SH
  12. Install the upper intake manifold brace, bolt (2), and stud (1).

    13. Tighten
    Tighten the bolts.

    12.1. Tighten the bolt (2) to 65 N·m (48 lb ft).
    12.2. Tighten the stud (1) to 10 N·m (89 lb in).

    Object Number: 887881 Size: SH

    Notice: Ensure proper engagement of the wiring harness connector. The wiring harness connector must be installed straight onto the component connector and firmly seated. Visually inspect the connector to ensure that the connector latches are engaged and locked. Any damage to the connector or wiring must be repaired. Failure to follow this procedure can lead to an intermittent electrical connection, driveability concerns, and/or wiring harness or wiring harness connector damage or failure.

  13. Connect the throttle body electrical connector.

    14. Object Number: 1285256 Size: SH
  14. Install the wiring harness retainer.

    15. Object Number: 1348201 Size: SH
  15. Connect the purge line (3) to the purge solenoid valve.

    16. Object Number: 887878 Size: SH
  16. Connect the purge solenoid valve electrical connector.
  17. Connect the brake booster vacuum hose to the intake manifold.

    18. Object Number: 1305320 Size: SH
  18. Install the air inlet duct. Refer to Air Cleaner Inlet Duct Replacement .
  19. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .