Sierra, Silverado 2006-2007

Cylinder Head

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Removal & Installation



4.3L Engine
Left Side
  1. 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
     

  2.  
  3. Clean the cylinder head bolts and the engine block bolt holes.
  4.  

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

     

  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
  1. 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
     

  2.  
  3. Clean the engine block and the cylinder head sealing surfaces.
  4.  

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
     

  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 & 6.2L Engines
Left Side

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. Remove or disconnect the following:
    NOTE
    The M11 cylinder head bolts are NOT reusable. Install NEW M11 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
     
    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
     

  2.  
  3. Remove the cylinder head bolts.
    NOTE
    After removal, place the cylinder head on two wood blocks to prevent damage.

  4.  
  5. Remove the gasket. Discard the gasket. Discard the M11 cylinder head bolts.
  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 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 M11 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.
    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

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. Remove or disconnect the following:
    NOTE
    The M11 cylinder head bolts are NOT reusable. Install NEW M11 cylinder head bolts during reassembly.


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



    Negative battery cable
     
    Coolant air bleed pipe
     
    Intake manifold
     
    Push rods
     
    Exhaust manifold(s)
     
    Alternator
     
    Alternator mounting bracket-to-cylinder head bolts
     
    Bolt behind the power steering pump
     
    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
     

  2.  
  3. Remove the gasket. Discard the gasket. Discard the M11 cylinder head bolts.
  4.  

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 M11 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.

      Click image to see an enlarged view

      Fig. Locating tab-4.8L, 5.3L, 6.0L and 6.2L engines



      Click image to see an enlarged view

      Fig. Cylinder head bolt tightening sequence-4.8L, 5.3L, 6.0L and 6.2L engines

    8.  

  12.  
  13. Install or connect the following:

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

  14.  

6.6L Engine
  1. Relieve the fuel system pressure.
  2.  
  3. Drain the coolant system.
  4.  
  5. Remove or disconnect the following:

    Negative battery cables
     
    Left or right front splash shield from the fender well, as applicable
     
    Turbocharger
     
    Turbocharger charged air cooler inlet duct
     
    Thermostat housing crossover
     
    Left or right intake manifold, as necessary
     
    Upper left or right valve cover
     
    Fuel rail assembly
     
    Left or right exhaust manifold
     
    Bolt and ground straps from the rear of the cylinder head
     
    Lower left or right valve cover
     
    Rocker arm shaft assembly
     
    Glow plugs
     
    Fuel injector return pipe eye bolts and washers
     
    Fuel injector return pipe assembly
     
    Fuel injector bracket bolts
     
    Fuel injectors with the brackets, using a suitable removal tool
     
    Injector bracket pins
     
    Cylinder head bolts, in the proper sequence
     
    Cylinder head and gasket. Discard the gasket

    Click image to see an enlarged view

    Fig. Cylinder head bolt loosening sequence-6.6L engines

     

  6.  

To install:

  1. Clean the mating surfaces of the heads and block thoroughly.
  2.  
  3. Position a new left or right side head gasket on the block. Note that the left and right side gaskets are NOT interchangeable.
    NOTE
    The cylinder head bolts on these vehicles are pre-coated with an application of a molybdenum disulfide for thread lubrication. Do not remove the coating or add any additional lubrication.

  4.  
  5. Install the cylinder head and bolts.
  6.  
  7. Tighten the cylinder head bolts, in sequence, as follows:
    1. Step 1: M12 bolts to 37 ft. lbs. (50 Nm).
    2.  
    3. Step 2: M12 bolts to 59 ft. lbs. (80 Nm).
    4.  
    5. Step 3: Using a torque angle meter, tighten the M12 bolts an additional 90 degrees on 2005 models or 60 degrees on 2006-07 models.
    6.  
    7. Step 4: Using a torque angle meter, tighten the M12 bolts an additional 75 degrees on 2005 models or 60 degrees on 2006-07 models.
    8.  
    9. Step 5: M8 bolts to 18 ft. lbs. (25 Nm).

      Click image to see an enlarged view

      Fig. Cylinder head bolt tightening sequence-6.6L engines

    10.  

  8.  
  9. Install or connect the following:
    NOTE
    If you are reusing the old injectors, clean the carbon from the tips, but do not use a wire brush.



    New O-ring onto the fuel injectors after coating with clean engine oil
     
    New copper washer into the fuel injector bore in the cylinder head
     
    Fuel injector bracket pin
     



    Fuel injector bracket bolt and tighten to 37 ft. lbs. (50 Nm)
     
    Fuel injector return pipe assembly
     
    Fuel injector return pipe-to-injector eye bolts and washers. Tighten to 11 ft. lbs. (15 Nm).
     
    Fuel return pipe-to-cylinder head eye bolts and washers. Tighten to 11 ft. lbs. (15 Nm).
     
    Bolt and ground straps to the rear of the cylinder head. Tighten to 18 ft. lbs. (25 Nm).
     
    Valve rocker shaft assembly
     
    Lower and upper valve covers
     
    Glow plugs
     
    Exhaust manifold
     
    Fuel rail assembly
     
    Intake manifold
     
    Thermostat housing crossover
     
    Turbocharger charged air cooler duct
     
    Clamp and hose to the charged air cooler. Tighten to 53 inch lbs. (6 Nm).
     
    Turbocharger
     
    Fender splash shield
     
    Negative battery cables
     

  10.  
  11. Refill the cooling system with the proper type and quantity of antifreeze.
  12.  
  13. Recharge the air conditioning system.
  14.  

8.1L Engine
Left Side
  1. Drain the cooling system.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Water crossover
     
    Intake manifold
     
    Valve cover
     
    Rocker arms and pushrods, keeping them in order for installation
     
    Engine harness ground bolts
     

  4.  
  5. Reposition the engine harness grounds and ground straps from the cylinder head.
    NOTE
    The cylinder head bolts must be replaced for installation.



    Exhaust manifold
     
    Cylinder head bolts, then discard
     



    Cylinder head. Place the head on 2 wood blocks to protect the sealing surfaces while it is removed.
     

  6.  

To install:


NOTE
The cylinder head should be cleaned and inspected for warpage or damage before installation.

  1. Thoroughly clean the mating surfaces of the head and block. Clean the bolt holes thoroughly.
    NOTE
    If a composition gasket is used, do not use sealer.

  2.  
  3. Align the cylinder head gasket locating marks to face up. Make sure that the gasket tabs are located of the No. 1 and 2 cylinder for proper installation.
  4.  
  5. Install or connect the following:
    NOTE
    The long bolts are used in locations 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, and 17. The medium length bolts are used in locations 15 and 18. The short bolts are used in locations 4, 5, 12, and 13.



    New cylinder head gasket
     
    Cylinder head
     
    Sealer to the threads of new cylinder head bolts, if not pre-applied
     

  6.  
  7. Tighten the head bolts, in sequence, in 4 stages, as follows:
    1. Step 1: 22 ft. lbs. (30 Nm).
    2.  

  8.  
  9. Step 2: 22 ft. lbs. (30 Nm)
    1. Step 3: Additional 120 degrees using a torque angle meter.
    2.  
    3. Step 4: Torque bolt numbers. 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16 and 17 an additional 60 degrees.
    4.  
    5. Tighten bolts 15 and 18 an additional 45 degrees, and bolt numbers 4, 5, 12 and 13 an additional 30 degrees.

      Click image to see an enlarged view

      Fig. Cylinder head bolt tightening sequence-8.1L engines

    6.  

  10.  
  11. Install or connect the following:

    Exhaust manifold
     
    Water crossover
     
    Engine harness grounds and ground strap
     
    Rocker arms and pushrods
     
    Valve cover
     
    Intake manifold
     

  12.  
  13. Connect the battery cable and refill the cooling system.
  14.  

Right Side
  1. Drain the cooling system.
  2.  
  3. Remove or disconnect the following:
    NOTE
    The cylinder head bolts must be replaced for installation.



    Negative battery cable
     
    Intake manifold
     
    Valve cover
     
    Rocker arms and pushrods, keeping them in order for installation
     
    Engine Coolant Temperature (ECT) sensor clip from the bracket
     
    ECT sensor
     
    ECT sensor bracket bolt and bracket
     
    Heater inlet and outlet hoses from the hose bracket
     
    Water crossover
     
    Exhaust manifold
     
    Cylinder head bolts, then discard
     



    Cylinder head. Place the head on 2 wood blocks to protect the sealing surfaces while it is removed.
     

  4.  

To install:


NOTE
The cylinder head should be cleaned and inspected for warpage or damage before installation.

  1. Thoroughly clean the mating surfaces of the head and block. Clean the bolt holes thoroughly.
    NOTE
    If a composition gasket is used, do not use sealer.

  2.  
  3. Align the cylinder head gasket locating marks to face up. Make sure that the gasket tabs are located of the no. 1 and 2 cylinder for proper installation.
  4.  
  5. Install or connect the following:
    NOTE
    The long bolts are used in locations 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, and 17. The medium length bolts are used in locations 15 and 18. The short bolts are used in locations 4, 5, 12, and 13.



    New cylinder head gasket
     
    Cylinder head
     
    Sealer to the threads of new cylinder head bolts, if not pre-applied
     

  6.  
  7. Tighten the head bolts, in sequence, in 4 stages, as follows:
    1. Step 1: 22 ft. lbs. (30 Nm).
    2.  

  8.  
  9. Step 2: 22 ft. lbs. (30 Nm)
    1. Step 3: Additional 120 degrees using a torque angle meter.
    2.  
    3. Step 4: Torque bolt numbers. 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16 and 17 an additional 60 degrees.
    4.  
    5. Tighten bolts 15 and 18 an additional 45 degrees, and bolt numbers 4, 5, 12 and 13 an additional 30 degrees.
    6.  

  10.  
  11. Install or connect the following:

    Exhaust manifold
     
    Water crossover
     
    Heater hose bracket and bolts. Tighten the bolts to 37 ft. lbs. (50 Nm).
     
    ECT sensor bracket and bolt. Tighten to 37 ft. lbs. (50 Nm).
     
    ECT sensor
     
    ECT sensor clip
     
    Rocker arms and pushrods
     
    Valve cover
     
    Intake manifold
     

  12.  
  13. Connect the battery cable and refill the cooling system.
  14.  

 
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