Isuzu Ascender 2003-05

Cylinder Head

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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.
  2.  


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).

  1. If using a steel only gasket, apply a thin and even coat of sealer to both sides of the gaskets.
  2.  
  3. 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.
  4.  
  5. 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.
  6.  
  7. Tighten the cylinder head bolts in sequence as follows:
    1. Tighten the long bolts (1-14), in sequence, to 22 ft. lbs. (30 Nm).
    2.  
    3. Tighten the long bolts, in sequence, an additional 155 degrees.
    4.  
    5. Tighten the 2 short end bolt to 62 inch lbs. (7 Nm).
    6.  
    7. Tighten the 2 short end bolts an additional 60 degrees.
    8.  
    9. Tighten the 1 long end bolts to 62 inch lbs. (7 Nm).
    10.  
    11. Tighten the 1 long end bolt an additional 120 degrees.
    12.  

  8.  
  9. 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
     

  10.  
  11. Properly refill the engine cooling system.
  12.  
  13. Run the engine to check for leaks.
  14.  


    Click image to see an enlarged view

    Fig. Cylinder head bolt tightening sequence-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 22 ft. lbs. (30 Nm).
    2.  
    3. Tighten the long bolts, in sequence, an additional 155 degrees.
    4.  
    5. Tighten the 2 short end bolts to 62 inch lbs. (7 Nm).
    6.  
    7. Tighten the 2 short end bolts an additional 60 degrees.
    8.  
    9. Tighten the 1 long end bolts to 62 inch lbs. (7 Nm).
    10.  
    11. Tighten the 1 long end bolt an additional 120 degrees.

      Click image to see an enlarged view

      Fig. Cylinder head bolt tightening sequence-4.2L engine

    12.  

  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.  

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.
  2.  


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.

  1. Check the cylinder head locating pins for proper installation, location (a) 0.327 in. (8.3mm), as shown.
  2.  
  3. 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.
  4.  
  5. Install or connect the following:

    Cylinder head
     

  6.  


    Click image to see an enlarged view

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



NOTE
You must use new cylinder head bolts during reassembly. Do NOT reuse the old head bolts.



NEW cylinder head bolts 1, 2 and 3.
 

  1. 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
    8.  

  2.  
  3. 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
     

  4.  
  5. Properly refill the engine cooling system.
  6.  
  7. Run the engine to check for leaks.
  8.  


    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence-5.3L engine


  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. 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. 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
     

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

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.
  2.  


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.

  1. Check the cylinder head locating pins for proper installation, location (a) 0.327 in. (8.3mm), as shown.
  2.  
  3. 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.
  4.  
  5. Install or connect the following:

    Cylinder head
     

  6.  


NOTE
You must use new cylinder head bolts during reassembly. Do NOT reuse the old head bolts.



NEW cylinder head bolts 1, 2 and 3.
 

  1. 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
    8.  

  2.  
  3. 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
     

  4.  
  5. Properly refill the engine cooling system.
  6.  
  7. Run the engine to check for leaks.
  8.  

  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. 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
    8.  

  10.  
  11. 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
     

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

 
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