Silverado 2008

Cylinder Head

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Removal & Installation



4.3L Engine
Left Side

Specific to:

Chevrolet Silverado 1500 2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.



    Battery negative cable
     
    Coolant
     
    Accessory drive belt
     
    Cooling fan assembly
     
    Power steering pump mounting bracket
     
    Power steering pump mounting bracket stud from the cylinder head
     
    Lower intake manifold
     
    Exhaust manifold
     
    Spark plug wire harness and the spark plug wire support
     
    Valve pushrods
     
    Ground strap and ground wire bolt from the rear of the cylinder head
     
    Engine Coolant Temperature (ECT) sensor (if applicable)
     
    ECT gauge sensor (if applicable)
     
    Spark plugs
     
    Spark plug wire support
     
    Cylinder head bolts
     
    Cylinder head and the gasket
     

  4.  
  5. Clean the cylinder head bolts and the engine block bolt holes.

    Click image to see an enlarged view

    Fig. Cylinder head and related components-4.3L engines

  6.  

To install:

  1. Inspect the dowel pins (cylinder head locator) for proper installation.
    NOTE
    Do not use any type sealer on the cylinder head gasket (unless specified).

  2.  
  3. Install or connect the following:

    NEW cylinder head gasket in position over the dowel pins (cylinder head locator)
     
    Cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
     
    Sealant GM P/N 12346004, or equivalent, to the threads of the cylinder head bolts
     
    Cylinder head bolts finger-tight

    Click image to see an enlarged view

    Fig. Dowel pin installation-4.3L engines



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence-4.3L engines

     

  4.  
  5. Tighten the cylinder head bolts in sequence:
    1. First pass: 22 ft. lbs. (30 Nm).
    2.  
    3. Second pass: Long bolts (1, 4, 5, 8, and 9)-+ 75 degrees.
    4.  
    5. Second pass: Medium bolts (12 and 13)-+ 65 degrees.
    6.  
    7. Second pass: Short bolts (2, 3, 6, 7, 10, and 11)-+ 55 degrees.
    8.  

  6.  
  7. Install or connect the following:

    Spark plug wire support and bolts. Tighten to 106 inch lbs. (12 Nm).
     
    Spark plugs. Tighten to 11 ft. lbs. (15 Nm), if USED; 22 ft. lbs. (30 Nm), if NEW.
     

  8.  
  9. If reusing the ECT gauge sensor (if applicable), apply sealant GM P/N 12346004 or equivalent to the threads of the ECT gauge sensor. Install the ECT gauge sensor (if applicable). Tighten the sensor to 15 ft. lbs. (20 Nm).
  10.  
  11. Install or connect the following:

    Ground strap and the ground wire bolt. Tighten the bolt to 12 ft. lbs. (16 Nm).
     
    Valve pushrods
     
    Lower intake manifold
     
    Exhaust manifold
     
    Stud for the power steering pump mounting bracket to the cylinder head. Tighten the power steering pump mounting bracket stud to 15 ft. lbs. (20 Nm).
     
    Power steering pump mounting bracket
     
    Engine cooling fan assembly
     
    Coolant
     
    Battery negative cable
     

  12.  

Right Side

Specific to:

Chevrolet Silverado 1500 2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Battery negative cable
     
    Coolant
     
    Engine cooling fan assembly
     
    Alternator mounting bracket
     
    Alternator mounting bracket stud from the cylinder head
     
    Lower intake manifold
     
    Exhaust manifold
     
    Spark plug wire harness and spark plug wire support
     
    Valve pushrods
     
    Cylinder head and the gasket
     

  4.  
  5. Clean the engine block and the cylinder head sealing surfaces.

    Click image to see an enlarged view

    Fig. Cylinder head and related components-4.3L engines

  6.  

To install:

Click image to see an enlarged view

Fig. Dowel pin installation-4.3L engines



Click image to see an enlarged view

Fig. Cylinder head bolt torque sequence-4.3L engines

  1. Inspect the dowel pins (cylinder head locator) for proper installation.
    NOTE
    Do not use any type sealer on the cylinder head gasket (unless specified).

  2.  
  3. Install or connect the following:

    NEW cylinder head gasket in position over the dowel pins (cylinder head locator)
     
    Cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
     
    Sealant GM P/N 12346004 or equivalent to the threads of the cylinder head bolts
     
    Cylinder head bolts finger-tight
     

  4.  
  5. Tighten the cylinder head bolts in sequence:
    1. First pass: 22 ft. lbs. (30 Nm).
    2.  
    3. Second pass: Long bolts (1, 4, 5, 8, and 9)-+ 75 degrees.
    4.  
    5. Second pass: Medium bolts (12 and 13)-+ 65 degrees.
    6.  
    7. Second pass: Short bolts (2, 3, 6, 7, 10, and 11)-+ 55 degrees.
    8.  

  6.  
  7. Install or connect the following:
    NOTE
    The front spark plug wire support bolt is used to fasten the oil level indicator tube, and will be installed within the oil level indicator tube installation procedure.



    Spark plug wire support and bolts. Tighten only the rear support bolt to 106 inch lbs. (12 Nm).
     



    Front spark plug wire support bolt
     
    Spark plugs. Tighten to 11 ft. lbs. (15 Nm), if USED; 22 ft. lbs. (30 Nm), if NEW.
     
    Valve pushrods
     
    Lower intake manifold
     
    Spark plug wire harness and wire support. Tighten to 106 inch lbs. (12 Nm).
     
    Exhaust manifold
     
    Stud for the alternator mounting bracket. Tighten the alternator mounting bracket stud to 15 ft. lbs. (20 Nm).
     
    Alternator mounting bracket
     
    Engine cooling fan assembly
     
    Coolant
     
    Battery negative cable
     

  8.  

4.8L, 5.3L & 6.0L Engines
Left Side

Specific to:

Chevrolet Silverado 1500 2008


CAUTION
Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures.

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    The cylinder head bolts are NOT reusable. Install NEW cylinder head bolts during assembly.



    Negative battery cable
     
    Intake manifold
     
    Push rods
     
    Exhaust manifold(s)
     
    Alternator
     
    Alternator mounting bracket-to-cylinder head bolts
     
    Bolt behind the power steering pump, as required
     
    Alternator mounting bracket and set it aside
     
    Oil level indicator tube-to-cylinder head bolt
     
    Oil level indicator tube
     
    Cylinder head from the engine
     
    Spark plugs
     

  4.  
  5. Remove the cylinder head bolts.
    NOTE
    After removal, place the cylinder head on two wood blocks to prevent damage.

  6.  
  7. Remove the gasket. Discard the gasket. Discard the cylinder head bolts.

    Click image to see an enlarged view

    Fig. Cylinder head and related components-4.8L, 5.3L & 6.0L engines

  8.  

To install:


NOTE
Do not use any type sealant on the cylinder head gasket (unless specified). The cylinder head gaskets must be installed in the proper direction and position.

  1. Clean the engine block cylinder head bolt holes (if required). Thread repair tool J 42385-107 may be used to clean the threads of old thread locking material.
  2.  
  3. Spray cleaner GM P/N 12346139, P/N 12377981, or equivalent into the hole.
  4.  
  5. Clean the cylinder head bolt holes with compressed air.
  6.  
  7. Check the cylinder head locating pins for proper installation.
    NOTE
    When properly installed, the tab on the left cylinder head gasket will be located left of center or closer to the front of the engine.

  8.  
  9. Install or connect the following:

    NEW left cylinder head gasket onto the locating pins
     
    Cylinder head onto the locating pins and the gasket
     
    NEW cylinder head bolts.
     

  10.  
  11. Apply a 0.20 in. (5mm) band of threadlock GM P/N 12345382 or equivalent to the threads of the M8 cylinder head bolts.

    M8 cylinder head bolts
     
    M8 cylinder head bolts.
     

  12.  
  13. Tighten the cylinder head bolts as follows:
    1. M11 bolts (1-10) 1st pass: in sequence to 22 ft. lbs. (30 Nm).
    2.  
    3. M11 bolts (1-10) 2nd pass: in sequence + 90 degrees.
    4.  
    5. M11 bolts (1-10): + 70 degrees.
    6.  
    7. M8 cylinder head bolts (11,12,13,14,15) to 22 ft. lbs. (30 Nm). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.

      Click image to see an enlarged view

      Fig. Locating tab-4.8L, 5.3L & 6.0L engines



      Click image to see an enlarged view

      Fig. Displacement markings-4.8L, 5.3L & 6.0L engines



      Click image to see an enlarged view

      Fig. Cylinder head gasket positioning-4.8L, 5.3L & 6.0L engines



      Click image to see an enlarged view

      Fig. Cylinder head bolt tightening sequence-4.8L, 5.3L & 6.0L engines

    8.  

  14.  
  15. Install or connect the following:

    Alternator mounting bracket. Tighten the four bolts to 37 ft. lbs. (50 Nm).
     
    Bolt at the rear of the power steering pump and tighten to 37 ft. lbs. (50 Nm).
     
    Exhaust manifold(s)
     
    Pushrods
     
    Intake manifold
     
    Negative battery cable
     

  16.  

Right Side

Specific to:

Chevrolet Silverado 1500 2008


CAUTION
Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures.

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    The cylinder head bolts are NOT reusable. Install NEW cylinder head bolts during reassembly.


    NOTE
    After removal, place the cylinder head on two wood blocks to prevent damage.



    Negative battery cable
     
    Engine coolant air bleed pipe
     
    Intake manifold
     
    Push rods
     
    Exhaust manifold
     
    Alternator
     
    Alternator mounting bracket-to-cylinder head bolts
     
    Bolt behind the power steering pump, as required
     
    Alternator mounting bracket and set it aside
     
    Bolt holding the oil level indicator tube to the right side cylinder head
     
    Oil level indicator tube
     
    Cylinder head(s) from the engine
     
    Spark plugs
     



    Cylinder head bolts
     

  4.  
  5. Remove the gasket. Discard the gasket. Discard the cylinder head bolts.

    Click image to see an enlarged view

    Fig. Cylinder head and related components-4.8L, 5.3L & 6.0L engines

  6.  

To install:


NOTE
Do not use any type sealant on the cylinder head gasket (unless specified). The cylinder head gaskets must be installed in the proper direction and position.

  1. Clean the engine block cylinder head bolt holes (if required). Thread repair tool J 42385-107 may be used to clean the threads of old thread locking material.
  2.  
  3. Spray cleaner GM P/N 12346139, P/N 12377981, or equivalent into the hole.
  4.  
  5. Clean the cylinder head bolt holes with compressed air.
  6.  
  7. Check the cylinder head locating pins for proper installation.
    NOTE
    When properly installed, the tab on the right cylinder head gasket will be located right of center or closer to the front of the engine.

  8.  
  9. Install or connect the following:

    NEW right cylinder head gasket onto the locating pins
     
    Cylinder head onto the locating pins and the gasket
     
    NEW cylinder head bolts. Apply a 0.20 in. (5mm) band of threadlock GM P/N 12345382 or equivalent to the threads of the M8 cylinder head bolts.
     
    M8 cylinder head bolts.
     

  10.  
  11. Tighten the cylinder head bolts as follows:
    1. M11 bolts (1-10) 1st pass: in sequence to 22 ft. lbs. (30 Nm).
    2.  
    3. M11 bolts (1-10) 2nd pass: in sequence + 90 degrees.
    4.  
    5. M11 bolts (1-10): + 70 degrees.
    6.  
    7. M8 cylinder head bolts (11,12,13,14,15) to 22 ft. lbs. (30 Nm). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.
    8.  

  12.  
  13. Install or connect the following:

    Alternator
     
    Exhaust manifold(s)
     
    Pushrods
     
    Intake manifold
     
    Negative battery cable

    Click image to see an enlarged view

    Fig. Locating tab-4.8L, 5.3L & 6.0L engines



    Click image to see an enlarged view

    Fig. Displacement markings-4.8L, 5.3L & 6.0L engines



    Click image to see an enlarged view

    Fig. Cylinder head gasket positioning-4.8L, 5.3L & 6.0L engines



    Click image to see an enlarged view

    Fig. Cylinder head bolt tightening sequence-4.8L, 5.3L & 6.0L engines

     

  14.  

 
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