GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Engine 🢒 Engine Electrical 🢒 Valve Rocker Arm Cover Replacement - Upper Right Side

Removal Procedure
  1. Remove air cleaner layer. Refer to Air Cleaner Replacement in Engine Controls - 6.6L.

    2. Object Number: 664851 Size: SH
  2. Loosen both hose clamps for the charged air cooler outlet duct to intake manifold tube hose.

    3. Important: Do not use a screwdriver or other prying tool to remove the hose.

  3. Using a twisting motion remove the hose from the intake manifold tube and the pipe.
  4. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim.
  5. Cover the opening on the pipe and the intake manifold tube with tape.
  6. Remove the fuel injection control module. Refer to Fuel Injector Control Module Replacement in Engine Controls - 6.6L.

    7. Object Number: 687021 Size: SH
  7. Disconnect positive crankcase ventilation (PCV) hose from the valve rocker arm cover.
  8. Remove the fuel injector lines.

    9. Object Number: 665256 Size: SH
  9. Remove the 11 bolts from the upper valve rocker arm cover.

    10. Note the location of any wire harness clips.

    Important: The upper valve rocker arm cover uses sealer. Pry only at the locations shown. Avoid damage to the sealing surfaces.

  10. Using a gasket scraper or other suitable tool at the prying locations, loosen the upper valve rocker arm cover.

    11. Object Number: 660467 Size: SH
  11. Remove the upper valve rocker arm cover.

    12. Object Number: 663628 Size: SH
  12. If replacing the upper valve rocker arm cover, remove the grommets for the injector line fittings.

    13. Object Number: 663733 Size: SH
  13. If replacing the upper valve rocker arm cover, remove the screws, PCV diaphragm, and spring.
  14. Inspect the PCV diaphragm for damage.
  15. Replace the PCV diaphragm if damage is found.
  16. Clean the sealer from the sealing surfaces on the upper valve rocker arm cover and the lower valve rocker arm cover.
  17. Clean the upper valve rocker arm cover in suitable cleaning solvent.
  18. Inspect for cracking and other damage on the upper valve rocker arm cover.
  19. Replace the upper valve rocker arm cover if any damage.

Installation Procedure

    Object Number: 663733 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  1. If removed, install the PCV diaphragm, spring, and screws.

    2. Tighten
    Tighten the PCV screws to 4 N·m (35 lb in).


    Object Number: 663628 Size: SH
  2. If removed, install NEW grommets for the injector line fittings.

    3. Object Number: 665277 Size: SH
  3. Apply a 2-3 mm (1/8 in) wide to 0.5-1.5 mm (1/16 in) high bead of sealant GM P/N 12378521 or equivalent to the upper valve rocker arm cover sealing surface.
  4. Apply a bead of sealant GM P/N 12378521 or equivalent to the area under the injector wire harness on the lower valve rocker arm cover.

    5. Object Number: 660467 Size: SH
  5. Install the upper valve rocker arm cover.

    6. Object Number: 663904 Size: SH
  6. Install the upper valve rocker arm cover bolts.

    7. Use the bolt tightening sequence. Bolts number 1 and 2 are used to position the valve rocker arm cover.

    Tighten

    1. Tighten the upper valve rocker arm cover bolts to 8 N·m (71 lb in) in the sequence shown.
    2. Tighten the upper valve rocker arm bolts again to 8 N·m (71 lb in) in the sequence shown.

    Object Number: 687021 Size: SH
  7. Install the fuel injector lines.

    8. Install fuel injector lines.

    Tighten
    Tighten the fuel injector lines to 41 N·m (30 lb ft).

  8. Connect PCV hoses to the upper valve rocker arm cover.
  9. Install the fuel injection control module. Refer to Fuel Injector Control Module Replacement in Engine Controls - 6.6L.

    10. Object Number: 664851 Size: SH
  10. Remove the tape from the charged air cooler outlet duct to charge air cooler pipe opening and the intake manifold tube opening.
  11. Position the hose on the pipe and the intake manifold tube.

    12. The hose is marked ENG for the intake manifold tube end and DUCT for the pipe end.

  12. Install the clamps and position as shown in order to allow the proper clearances.

    13. Tighten
    Tighten the hose clamps to 6 N·m (53 lb in).

  13. Install the charged air cooler inlet duct to the turbocharger.
  14. Align the duct to the turbocharger as shown.
  15. Position the hose clamps.

    16. Tighten
    Tighten the charged air cooler inlet duct clamps to 6 N·m (53 lb in).

  16. Check for external fuel leaks. Refer to Fuel Leak Diagnosis in Engine Controls - 6.6L.
  17. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim.
  18. Install air cleaner layer. Refer to Air Cleaner Replacement in Engine Controls - 6.6L.