Sierra, Silverado 2006-2007

Exhaust Manifold

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Removal & Installation



4.3L Engines
  1. Remove or disconnect the following:

    Negative battery cable
     
    Engine cover, if equipped
     
    Exhaust pipe from the exhaust manifold
     
    Spark plug wires from the plugs and the retaining clips
     
    Heat shields
     

    1. Remove the spark plugs, dipstick tube and wiring, if necessary.
    2.  

  2.  
  3. Unbend the exhaust manifold bolt lock tangs.
  4.  
  5. Remove or disconnect the following:

    Exhaust manifold retaining bolts, washers and tab washers
     
    Exhaust manifold
     
    Old gaskets and discard
     

  6.  

To install:

  1. Clean the gasket mounting surfaces.
  2.  
  3. Inspect the exhaust manifold for distortion, cracks or damage; replace if necessary.
  4.  
  5. Install or connect the following:

    Exhaust manifold to the cylinder using a new gasket.
     

  6.  
  7. Tighten the exhaust manifold bolts and stud on the first pass to 11 ft. lbs. (5 Nm).
  8.  
  9. Tighten the exhaust manifold bolts and stud on the final pass to 22 ft. lbs.(30 Nm).
    NOTE
    Once the bolts are tightened, bend the tabs on the washers back over the heads of all bolts in order to lock them in position.



    Spark plugs
     
    Dipstick tube
     
    Spark plug wires to the retainer clips and plugs
     
    Exhaust pipe to the manifold
     
    Engine cover (if equipped)
     
    Negative battery cable
     

  10.  

4.8L, 5.3L, 6.0L & 6.2L Engines
  1. Remove or disconnect the following:
    NOTE
    Do not remove the spark plug wires from the ignition coils unless required.



    Spark plug wires from the spark plugs
     



    Click image to see an enlarged view

    Fig. Right exhaust manifold removal-4.8L, 5.3L, 6.0L and 6.2L; left side similar



    Exhaust manifold, bolts, and gasket. Discard the gasket.
     
    Heat shield and bolts from the manifold, if required
     

  2.  

To install:


NOTE
Do not reuse the exhaust manifold-to-cylinder head gaskets. Upon installation of the exhaust manifold, install a NEW gasket. A improperly installed gasket or leaking exhaust system may effect On-Board Diagnostics (OBD) II system performance.

  1. Clean the exhaust manifold and heat shield in solvent. Dry the exhaust manifold with compressed air.
  2.  
  3. Use a straight edge and a feeler gauge and measure the exhaust manifold cylinder head deck for warpage. An exhaust manifold deck with warpage in excess of 0.01 in. (0.25mm) within the two front or two rear runners or 0.02 in. (0.5mm) overall, may cause an exhaust leak and may effect OBD II system performance. Exhaust manifolds not within specifications must be replaced.
  4.  
  5. Apply a 0.2 in. (5mm) wide band of threadlock GM P/N 12345493 or equivalent to the threads of the exhaust manifold bolts.
  6.  
  7. Install the exhaust manifold gasket and exhaust manifold
  8.  
  9. Install the exhaust manifold bolts and tighten, beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
    1. Tighten the exhaust manifold bolts first pass to 11 ft. lbs. (15 Nm). Begin with the center 2 bolts, then alternate from side to side working outwards.
    2.  
    3. Tighten the exhaust manifold bolts final pass to 18 ft. lbs. (25 Nm). Begin with the center 2 bolts, then alternate from side to side working outwards. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the front of the right cylinder head.
    4.  

  10.  
  11. Install or connect the following:

    Heat shield and bolts and tighten to 80 inch lbs. (9 Nm)
     
    Spark plug wires
     

  12.  

6.6L Engine
Left Side
  1. Raise the vehicle.
  2.  
  3. Remove or disconnect the following:

    Bolts securing the left exhaust pipe heat shield and move the heat shield aside
     
    Left exhaust pipe-to-manifold bolts
     
    Left front wheel
     
    Left front fender splash shield
     
    Charge air cooler duct
     
    Exhaust manifold heat shield bolts and shield
     
    2 nuts and 6 bolts with the plain washer and bell view washer from the left manifold
     
    Exhaust manifold by removing it from the rear, then the front studs and sliding it out the bottom, past the oil filter
     
    Exhaust manifold gasket and discard
     

  4.  

To install:

  1. Installation is the reverse of the removal procedure. Tighten the retainers as follows:
    1. Exhaust manifold nuts and bolts, in sequence, in 2 passes to 25 ft. lbs. (34 Nm).

      Click image to see an enlarged view

      Fig. Left and right side exhaust manifold bolt removal and installation sequence-6.6L engines

    2.  
    3. Heat shield bolts: 71 inch lbs. (8 Nm).
    4.  
    5. Exhaust pipe-to-manifold bolts: 39 ft. lbs. (59 Nm).
    6.  

  2.  

Right Side
  1. Raise the vehicle.
  2.  
  3. Remove or disconnect the following:

    Right front wheel
     
    Right front fender splash shield
     
    Exhaust manifold heat shield bolts and shield
     
    Right exhaust pipe-to-manifold bolts
     
    2 nuts and 6 bolts with the plain washer and bell view washer from the left manifold
     
    Exhaust manifold by removing it from the rear, then the front studs and sliding it out the bottom, past the oil filter
     
    Bolt for the oil level dipstick tube, to remove the gasket
     
    Exhaust manifold gasket and discard
     

  4.  

To install:

  1. Installation is the reverse of the removal procedure. Tighten the retainers as follows:
    1. Oil level dipstick tube: 15 ft. lbs. (20 Nm).
    2.  
    3. Exhaust manifold nuts and bolts, in sequence, in 2 passes: 25 ft. lbs. (34 Nm).
    4.  
    5. Heat shield bolts: 71 inch lbs. (8 Nm).
    6.  
    7. Exhaust pipe-to-manifold bolts: 39 ft. lbs. (59 Nm).
    8.  

  2.  

8.1L Engines
  1. Remove or disconnect the following:

    Spark plug wires
     
    Spark plugs
     
    Exhaust manifold heat shield bolts and shield
     
    Exhaust manifold bolt and nuts
     
    Exhaust manifold
     
    Exhaust manifold gasket and discard
     

  2.  

To install:

  1. Clean the mating surfaces and the retainer threads.
  2.  
  3. Install or connect the following:

    New exhaust manifold gasket
     
    Exhaust manifold
     
    Exhaust manifold bolt and nuts. Tighten the bolt to 26 ft. lbs. (35 Nm) and the nuts to 12 ft. lbs. (16 Nm).
     
    If removed, tighten the studs to 15 ft. lbs. (20 Nm).
     
    Heat shield. Tighten the retaining bolts and nuts to 18 ft. lbs. (25 Nm).
     
    Spark plugs and plug wires
     

  4.  

 
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