GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 Sonoma Pickup - 4WD 🢒 Engine 🢒 Engine Mechanical - 4.3L 🢒 Valve Rocker Arm Cover Replacement - Left Side

Removal Procedure

    Object Number: 444792 Size: SH
  1. Disconnect the breather tube at the air cleaner outlet duct.

    2. Object Number: 312278 Size: SH
  2. Remove the air cleaner outlet duct retaining wingnut.

    3. Object Number: 10940 Size: SH
  3. Disconnect the IAT sensor harness connector.

    4. Object Number: 424556 Size: SH
  4. Remove the air cleaner outlet duct from the throttle body.
  5. Partially drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  6. Remove the radiator inlet hose from the water outlet housing. Refer to Radiator Inlet Hose Replacement in Engine Cooling.

    7. Object Number: 172995 Size: SH
  7. Remove the PCV valve hose assembly from the valve rocker arm cover.

    8. Object Number: 246797 Size: SH
  8. Disconnect the engine coolant temperature (ECT) sensor electrical connector.

    9. Object Number: 172982 Size: SH
  9. Remove the spark plug wire harness retainer from the exhaust gas recirculation (EGR) valve inlet pipe.
  10. Remove the clamp bolt for the EGR valve inlet pipe.
  11. Remove the EGR valve inlet pipe from the intake and the exhaust manifolds.

    12. Object Number: 328566 Size: SH

    Important: A/C compressor and bracket removal is not necessary.

  12. Remove the valve rocker arm cover bolts.
  13. Remove the valve rocker arm cover bolt grommets.
  14. Discard the valve rocker arm cover bolt grommets.

    15. Object Number: 480519 Size: SH
  15. Remove the valve rocker arm cover.

    16. Object Number: 328573 Size: SH
  16. Remove the valve rocker arm cover gasket.
  17. Discard the valve rocker arm cover gasket.

    18. Object Number: 334508 Size: SH
  18. Clean the valve rocker arm cover in cleaning solvent.
  19. Dry the valve rocker arm cover with compressed air.
  20. Inspect the valve rocker arm cover for the following:
    21. • Damage to the PCV valve grommet (1)
    • Damage to the bolt holes (2)
    • A damaged valve rocker arm cover may interfere with the valve rocker arms.
    • Damage to the exterior of the valve rocker arm cover (3)
    • Gouges or damage to the sealing surface (4)
    • Damage to the oil fill tube grommet (5)
    • Restrictions to the ventilation system passages

Installation Procedure

    Object Number: 328573 Size: SH

    Important: Do not reuse the valve cover gasket or the valve rocker arm cover bolt grommets.

  1. Install the NEW valve rocker arm cover gasket into the groove of the valve rocker arm cover.
  2. Install the NEW valve rocker arm cover bolt grommets into the valve rocker arm cover.

    3. Object Number: 480519 Size: SH
  3. Install the valve rocker arm cover onto the cylinder head.

    4. Object Number: 328566 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.

  4. Install the valve rocker arm cover bolts.

    5. Tighten
    Tighten the valve rocker arm cover bolts to 12 N·m (106 lb in).


    Object Number: 172982 Size: SH
  5. Install the EGR valve inlet pipe to the intake manifold and the exhaust manifold.

    6. Tighten

    1. Tighten the EGR valve inlet pipe intake manifold nut to 25 N·m (18 lb ft).
    2. Tighten the EGR valve inlet pipe exhaust manifold nut to 30 N·m (22 lb ft).
    3. Tighten the EGR valve inlet pipe clamp bolt 25 N·m (18 lb ft).
  6. Install the spark plug wire harness retainer on the EGR valve inlet pipe.

    7. Object Number: 172995 Size: SH
  7. Install the radiator inlet hose to the water outlet housing. Refer to Radiator Inlet Hose Replacement in Engine Cooling.
  8. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  9. Install the PCV valve hose assembly to the valve rocker arm cover.

    10. Object Number: 246797 Size: SH
  10. Connect the ECT sensor electrical connector.

    11. Notice: 

       • Handle the MAF sensor carefully.
       • Do not drop the MAF sensor in order to prevent damage to the MAF sensor.
       • Do not damage the screen located on the air inlet end of the MAF.
       • Do not touch the sensing elements.
       • Do not allow solvents and lubricants to come in contact with the sensing elements.
       • Use a small amount of a soap based solution in order to aid in the installation.


    Object Number: 424556 Size: SH
  11. Install air cleaner outlet duct to throttle body.
  12. Install air cleaner outlet duct to MAF sensor.

    13. Tighten
    Tighten the hose clamp to 4 N·m (32 lb in).


    Object Number: 10940 Size: SH
  13. Connect the IAT sensor harness connector.

    14. Object Number: 312278 Size: SH
  14. Install the air cleaner outlet duct retaining wingnut.

    15. Tighten
    Tighten the wingnut to 2 N·m (18 lb in).


    Object Number: 444792 Size: SH
  15. Connect the breather tube to the air cleaner outlet duct.