GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2004 🢒 CTS 🢒 Engine 🢒 Engine Cooling 🢒 Intake Manifold Replacement

Removal Procedure
  1. Remove the intake plenum. Refer to Intake Plenum Replacement .
  2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief in Engine Controls-2.6L and 3.2L.

    3. Object Number: 785815 Size: MH
  3. Refer to Metal Collar Quick Connect Fitting Service in order to disconnect the following quick connect fittings from the fuel rail:
    4. • The return hose/pipe (1)
    • The feed hose/pipe (2)
    • Plug the open outlet ports to prevent fuel loss and contamination.

    Object Number: 785853 Size: SH
  4. Disconnect the fuel injector electrical harness connector (2) from the engine wiring harness connector (3).
  5. Disconnect the fuel pressure regulator vent tube from the fuel pressure regulator.
  6. Remove the fuel rail if intake manifold replacement is necessary. Refer to Fuel Injector and Fuel Rail Replacement in Engine Controls-2.6L and 3.2L.

    7. Object Number: 217280 Size: SH
  7. Remove the intake manifold bolts (1).
  8. Remove the intake manifold (2) from the intake manifold flange.
  9. Remove the seals (3).
  10. Mask off the open ports to the intake manifold flange, in order to prevent foreign objects from entering the engine.
  11. If necessary, disassemble the intake manifold. Refer to Intake Manifold Disassemble .
  12. Clean and inspect the intake manifold. Refer to Intake Manifold Cleaning and Inspection .

Installation Procedure
  1. If necessary, assemble the intake manifold. Refer to Intake Manifold Assemble .
  2. Remove the masking from the intake manifold flange and ensure the sealing surfaces are clean and dry.

    3. Object Number: 217280 Size: SH
  3. Install the seals (3) into the intake manifold flange grooves.
  4. Position the intake manifold (2) to the intake manifold flange.

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

  5. Install the intake manifold bolts (1).

    6. Tighten
    Tighten the intake manifold bolts to 20 N·m (15 lb ft).

  6. Install the fuel rail if previously removed. Refer to Fuel Injector and Fuel Rail Replacement in Engine Controls-2.6L and 3.2L.
  7. Connect the fuel pressure regulator vent tube to the fuel pressure regulator.

    8. Object Number: 785853 Size: SH
  8. Connect the fuel injector electrical harness connector (2) to the engine wiring harness connector (3).

    9. Object Number: 785815 Size: MH
  9. Refer to Metal Collar Quick Connect Fitting Service in order to connect the following quick connect fittings to the fuel rail:
    10. • The feed hose/pipe (2)
    • The return hose/pipe (1)
  10. Install the intake plenum. Refer to Intake Plenum Replacement .