S&T Series Blazer, Bravada, Envoy, Jimmy, Rainier, Trailblazer, Xtreme

Cylinder Head

Print

Removal & Installation



4.2L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Drain the engine cooling system.
  6.  
  7. Remove or disconnect the following:

    Camshaft cover
     
    Exhaust manifold
     
    Front cover
     
    Cylinder head access hole plugs
     
    Timing chain tensioner shoe bolt and shoe
     
    Timing chain tensioner guide bolts and guide
     
    Timing chain and sprockets
     

  8.  
  9. Unfasten the cylinder head bolts by loosening them in the reverse of the torque sequence, then carefully remove the cylinder head.
  10.  
  11. Remove the cylinder head gasket.
  12.  

To install:

  1. Carefully clean and inspect the cylinder head and the gasket mounting surfaces.
    NOTE
    The gasket surfaces on both the head and block must be clean of any foreign matter and free of nicks or heavy scratches. The cylinder bolt threads in the block and thread on the bolts must be cleaned (dirt will affect the bolt torque).


    NOTE
    DO NOT apply sealer to composition steel-asbestos gaskets.


    WARNING
    Make sure the number 1 cylinder is at Top Dead Center (TDC).

  2.  
  3. If using a steel only gasket, apply a thin and even coat of sealer to both sides of the gaskets.
  4.  
  5. Place a new gasket over the dowel pins with the bead or the words -This Side Up'' facing upwards (as applicable), then carefully lower the cylinder head into position over the gasket and dowels.
  6.  
  7. Apply a coating of 12345493 or equivalent sealer to the threads of the cylinder head bolts, then thread the bolts into position until finger-tight.
  8.  
  9. Tighten the cylinder head bolts in sequence as follows:
    1. Tighten the long bolts (1-14), in sequence, to 30 ft. lbs. (40 Nm).
    2.  
    3. Tighten the long bolts, in sequence, an additional 90 degrees.
    4.  
    5. Tighten the long bolts, in sequence, an additional 60 degrees.
    6.  
    7. Tighten the 2 long end bolts to 15 ft. lbs. (20 Nm).
    8.  
    9. Tighten the 1 short end bolt to 13 ft. lbs. (18 Nm).

      Click image to see an enlarged view

      Fig. Cylinder head bolt tightening sequence-4.2L engine

    10.  

  10.  
  11. Install or connect the following:

    Cylinder head access hole plugs and tighten to 44 inch lbs. (5 Nm)
     
    Timing chain and sprockets
     
    Front cover
     
    Camshaft cover
     
    Exhaust manifold
     
    Negative battery cable
     

  12.  
  13. Properly refill the engine cooling system.
  14.  
  15. Run the engine to check for leaks.
  16.  

4.3L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Properly relieve the fuel system pressure, then disconnect the negative battery cable.
  4.  
  5. Drain the engine cooling system.
  6.  
  7. Remove or disconnect the following:

    Intake manifold
     
    Exhaust manifold
     
    Alternator and bracket, if removing the right cylinder head
     
    Cooling fan assembly, on 2001 models
     
    Air conditioning compressor (position it aside with the refrigerant lines attached), on 2001 models equipped
     
    Air pipe bracket and nut from the rear of the power steering pump if removing the left cylinder head on equipped 2001 models
     
    Engine accessory bracket with power steering pump (position the pump aside with the lines attached) and brackets, if removing the left cylinder head
     
    Wiring harness and clip from the rear of the cylinder head
     
    Coolant sensor wire
     
    Wiring from the spark plugs
     
    Spark plugs, if necessary
     
    Ground wires and if necessary, the fuel line bracket from the rear of the cylinder head, on 2001 models
     
    Rocker arm cover
     

  8.  
  9. Loosen the rocker arms and remove the pushrods.
    NOTE
    If valve train components, such as the rocker arms or pushrods, are to be reused, they must be tagged or arranged to insure installation in their original locations.

  10.  
  11. Unfasten the cylinder head bolts by loosening them in the reverse of the torque sequence, then carefully remove the cylinder head.

    Click image to see an enlarged view

    Fig. Cylinder head and related components-4.3L engine

  12.  

To install:

  1. Carefully clean and inspect the cylinder head and the gasket mounting surfaces.
    NOTE
    The gasket surfaces on both the head and block must be clean of any foreign matter and free of nicks or heavy scratches. The cylinder bolt threads in the block and thread on the bolts must be cleaned (dirt will affect the bolt torque).


    NOTE
    DO NOT apply sealer to composition steel-asbestos gaskets.

  2.  
  3. If using a steel only gasket, apply a thin and even coat of sealer to both sides of the gaskets.
  4.  
  5. Place a new gasket over the dowel pins with the bead or the words -This Side Up'' facing upwards (as applicable), then carefully lower the cylinder head into position over the gasket and dowels.
  6.  
  7. Apply a coating of 12346004 or equivalent sealer to the threads of the cylinder head bolts, then thread the bolts into position until finger-tight.
  8.  
  9. Install the bolts in sequence to 22 ft. lbs. (30 Nm). The bolts must then be tightened again in sequence in the following order:
    1. Short length bolts: (11, 7, 3, 2, 6, 10) 55 degrees.
    2.  
    3. Medium length bolts: (12, 13) 65 degrees.
    4.  
    5. Long length bolts: (1, 4, 8, 5, 9) 75 degrees.

      Click image to see an enlarged view

      Fig. Cylinder head bolt torque sequence-4.3L engine

    6.  

  10.  
  11. Install or connect the following:

    Pushrods, secure the rocker arms and adjust the valves
     
    Rocker arm cover
     
    Spark plugs, if removed
     
    Spark plug wires
     
    Attach the fuel line bracket (if removed) and ground wires to the rear of the head and tighten the bolts to 22 ft. lbs. (30 Nm) on 2001 models
     
    Air conditioning compressor and bracket, if the left cylinder head was removed
     
    Alternator and bracket, if the right cylinder head was removed
     
    Engine accessory bracket with power steering pump. if the left cylinder head was removed
     
    Air pipe bracket and nut to the rear of the power steering pump (if equipped), if the left cylinder head was removed on 2001 models. Tighten the nut to 30 ft. lbs. (41 Nm).
     
    A/C compressor, if the left cylinder head was removed
     
    Cooling fan assembly, if the left cylinder head was removed on 2001 models
     
    Wiring harness and clip to the rear of the cylinder head
     
    Coolant sensor wire
     
    Exhaust manifold
     
    Intake manifold
     
    Negative battery cable
     

  12.  
  13. Properly refill the engine cooling system.
  14.  
  15. Run the engine to check for leaks.
  16.  

5.3L Engine
Left Side
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Drain the engine cooling system.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Alternator bracket
     
    Coolant air bleed pipe
     
    Left exhaust manifold
     
    Pushrods
     
    Auxiliary A/C bracket bolt, if equipped
     
    Cylinder head bolts 1, 2 and 3. Discard the bolts

    Click image to see an enlarged view

    Fig. Remove and discard cylinder head bolts 1, 2 and 3-5.3L engine

     
    Cylinder head
     
    Cylinder head gasket and discard
     

  6.  

To install:

  1. Carefully clean and inspect the cylinder head and the gasket mounting surfaces.
    NOTE
    The gasket surfaces on both the head and block must be clean of any foreign matter and free of nicks or heavy scratches. The cylinder bolt threads in the block and thread on the bolts must be cleaned (dirt will affect the bolt torque).


    NOTE
    DO NOT apply any type sealer to the cylinder head gasket, unless otherwise specified.

  2.  
  3. Check the cylinder head locating pins for proper installation, location (a) 0.327 in. (8.3mm), as shown.

    Click image to see an enlarged view

    Fig. Make sure the cylinder head locating pins are properly installed, see dimension (a)

  4.  
  5. Place a new gasket over the dowel pins. When installed properly, the word -FRONT- on the left side, the tab on the gasket should be left of center or closer to the front of the engine.
  6.  
  7. Install or connect the following:
    NOTE
    You must use new cylinder head bolts during reassembly. Do NOT reuse the old head bolts.



    Cylinder head
     



    NEW cylinder head bolts 1, 2 and 3.
     

  8.  
  9. For 2003-04 vehicles, tighten the cylinder head bolts in sequence as follows:
    1. Tighten the M11 bolts to 22 ft. lbs. (30 Nm).
    2.  
    3. Tighten the M11 an additional 90 degrees.
    4.  
    5. Tighten M11 bolts 1-8, an additional 90 degrees and M11 bolts 9 and 10 an additional 50 degrees.
    6.  
    7. Tighten the M8 bolts (11-15) to 22 ft. lbs. (30 Nm). Tighten all the bolts beginning with the center bolt and working outward, alternating sides

      Click image to see an enlarged view

      Fig. Cylinder head bolt torque sequence-5.3L engine

    8.  

  10.  
  11. For 2005 vehicles, tighten the cylinder head bolts in sequence as follows:
    1. Tighten the M11 bolts to 22 ft. lbs. (30 Nm).
    2.  
    3. Tighten the M11 an additional 90 degrees.
    4.  
    5. Tighten M11 bolts, an additional 70 degrees.
    6.  
    7. Tighten the M8 bolts to 22 ft. lbs. (30 Nm). Tighten all the bolts beginning with the center bolt and working outward, alternating sides
    8.  

  12.  
  13. Install or connect the following:

    Auxiliary A/C bracket, if equipped. Torque the bolt to 15 ft. lbs. (20 Nm).
     
    Pushrods
     
    Left exhaust manifold
     
    Coolant air bleed pipe
     
    Alternator bracket
     

  14.  
  15. Properly refill the engine cooling system.
  16.  
  17. Run the engine to check for leaks.
  18.  

Right Side
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Drain the engine cooling system.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Oil level dipstick
     
    Coolant air bleed pipe
     
    Right exhaust manifold
     
    Pushrods
     
    Auxiliary A/C bracket nut, if equipped
     
    Cylinder head bolts 1, 2 and 3. Discard the bolts
     
    Cylinder head
     
    Cylinder head gasket and discard
     

  6.  

To install:

  1. Carefully clean and inspect the cylinder head and the gasket mounting surfaces.
    NOTE
    The gasket surfaces on both the head and block must be clean of any foreign matter and free of nicks or heavy scratches. The cylinder bolt threads in the block and thread on the bolts must be cleaned (dirt will affect the bolt torque).


    NOTE
    DO NOT apply any type sealer to the cylinder head gasket, unless otherwise specified.

  2.  
  3. Check the cylinder head locating pins for proper installation, location (a) 0.327 in. (8.3mm), as shown.
  4.  
  5. Place a new gasket over the dowel pins. When installed properly, the word -FRONT- on the right side, the tab on the gasket should be right of center or closer.
  6.  
  7. Install or connect the following:
    NOTE
    You must use new cylinder head bolts during reassembly. Do NOT reuse the old head bolts.



    Cylinder head
     



    NEW cylinder head bolts 1, 2 and 3.
     

  8.  
  9. For 2003-04 vehicles, tighten the cylinder head bolts in sequence as follows:
    1. Tighten the M11 bolts to 22 ft. lbs. (30 Nm).
    2.  
    3. Tighten the M11 an additional 90 degrees.
    4.  
    5. Tighten M11 bolts 1-8, an additional 90 degrees and M11 bolts 9 and 10 an additional 50 degrees.
    6.  
    7. Tighten the M8 bolts (11-15) to 22 ft. lbs. (30 Nm). Tighten all the bolts beginning with the center bolt and working outward, alternating sides

      Click image to see an enlarged view

      Fig. Cylinder head bolt torque sequence-5.3L engine

    8.  

  10.  
  11. For 2005 vehicles, tighten the cylinder head bolts in sequence as follows:
    1. Tighten the M11 bolts to 22 ft. lbs. (30 Nm).
    2.  
    3. Tighten the M11 an additional 90 degrees.
    4.  
    5. Tighten M11 bolts, an additional 70 degrees.
    6.  
    7. Tighten the M8 bolts to 22 ft. lbs. (30 Nm). Tighten all the bolts beginning with the center bolt and working outward, alternating sides
    8.  

  12.  
  13. Install or connect the following:

    Auxiliary A/C bracket, if equipped. Torque the nut to 15 ft. lbs. (20 Nm).
     
    Pushrods
     
    Right exhaust manifold
     
    Coolant air bleed pipe
     
    Oil level dipstick
     

  14.  
  15. Properly refill the engine cooling system.
  16.  
  17. Run the engine to check for leaks.
  18.  

 
label.common.footer.alt.autozoneLogo