Avalanche, Sierra, Silverado, C&K Series, 1999-2005

Intake Manifold 2

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Removal & Installation



5.7L And 7.4L Engines
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    Note the location of the manifold bolts and studs before removal for reassembly in their original positions.


    NOTE
    Do not disassemble the Central Sequential Fuel Injection (CSFI) unit.



    Negative battery cable
     
    Engine cover
     
    Air cleaner intake duct
     
    Coolant reservoir
     
    Wiring harness connectors and brackets
     
    Throttle linkage and bracket from the upper intake manifold
     
    Cruise control cable, if equipped
     
    Fuel lines and the bracket from the rear of the intake manifold
     
    Positive Crankcase Ventilation (PCV) valve and hoses
     
    Ignition coil and bracket
     
    Purge solenoid and bracket
     



    Intake manifold bolts and studs
     



    Upper intake manifold
     

  4.  
  5. Clean the old gasket residue from both mating surfaces.

    Distributor
     
    Upper radiator hose from the thermostat housing
     
    Heater hose from the lower intake manifold
     
    Coolant bypass hose
     
    Exhaust Gas Recirculation (EGR) valve
     
    Fuel pressure and return lines from the lower intake manifold
     
    Wiring harnesses and brackets from the lower manifold
     
    Left side valve cover
     
    Transmission oil level indicator and tube, if equipped
     
    EGR tube, clamp and bolt
     
    Positive Crankcase Ventilation (PCV) valve and hoses
     
    Air conditioning compressor and bracket, but do not disconnect the lines
     

  6.  
  7. Loosen the compressor mounting bracket and slide it forward, but do not remove it.

    Power brake vacuum tube
     
    Lower intake manifold bolts and lower intake manifold
     

  8.  

To install:

  1. Clean all gasket surfaces completely.
  2.  
  3. Install the intake manifold gaskets with the port blocking plates facing the rear. Factory gaskets should have the words This Side Up visible.
  4.  
  5. Apply gasket sealer to the front and rear sealing surfaces of the engine block. Extend the sealer approximately 1 / 2 inch (13mm) onto the heads.
  6.  
  7. Install the lower intake manifold.
  8.  
  9. Apply sealer to the lower intake manifold bolts prior to installation.
  10.  
  11. On the 5.7L engines, install the bolts and torque in sequence as follows:
    1. Step 1: Torque the bolts to 71 inch lbs. (8 Nm).
    2.  
    3. Step 2: Torque the bolts to 106 inch lbs. (12 Nm).
    4.  
    5. Step 3: Torque the bolts to 11 ft. lbs. (15 Nm).
    6.  

  12.  
  13. On the 7.4L engine, torque the bolts to 30 ft. lbs. (40 Nm) in the sequence shown.

    Click image to see an enlarged view

    Fig. Lower intake manifold bolt tightening sequence-5.7L engines



    Click image to see an enlarged view

    Fig. Upper and lower intake manifold bolt tightening sequence-7.4L engines

  14.  
  15. Install or connect the following:
    WARNING
    When installing the upper intake manifold be careful not to pinch the injector wires between the upper and lower intake manifolds.



    Power brake vacuum tube
     
    PCV valve and hose
     
    EGR tube, clamp and bolt
     
    Transmission oil level indicator and tube, if equipped
     
    Left side valve cover
     
    Wiring harnesses and brackets to the lower manifold
     
    Fuel pressure and return lines to the lower intake manifold
     
    EGR valve
     
    Coolant bypass hose
     
    Heater hose to the lower intake manifold
     
    Upper radiator hose to the thermostat housing
     
    Air conditioning compressor and bracket
     
    Distributor
     
    Upper intake manifold gasket
     
    Upper intake manifold
     



    Upper intake manifold mounting bolts/studs, torque in a crisscross pattern as follows:
     

    1. Step 1: Torque to 44 inch lbs. (5 Nm).
    2.  
    3. Step 2: Torque to 83 inch lbs. (10 Nm).

      Purge solenoid and bracket
       
      PCV hose
       
      Fuel lines and the bracket at the rear of the intake manifold
       
      Ignition coil and bracket
       
      Throttle linkage and bracket to the upper intake manifold
       
      Throttle linkage cable
       
      Cruise control cable, if equipped
       
      Wiring harness connectors and brackets
       
      Air cleaner intake duct
       
      Coolant recovery reservoir and the engine cover
       
      Negative battery cable
       

    4.  

  16.  
  17. Start the vehicle and verify that there are no leaks.
  18.  

6.5L Engine
  1. Recover the air conditioning refrigerant and reposition air conditioning lines.
  2.  
  3. Remove or disconnect the following:
    WARNING
    Do not remove the center intake and side intakes as an assembly. Damage to the center intake and turbocharger may occur.



    Negative battery cable
     
    Air cleaner assembly
     
    Fuel lines, and electrical connections
     
    Engine and transmission oil level tubes
     



    Center intake assembly, and glow plug relay
     
    Side intake bolts and fuel retaining clips
     
    Side intakes
     

  4.  
  5. Clean all gasket surfaces.
  6.  

To install:

  1. Install or connect the following:

    Side intakes and new gaskets. Torque the bolts to 31 ft. lbs. (42 Nm).
     
    Fuel lines retaining clips and electrical connection
     
    Center intake with new gaskets. Torque the bolts to 17 ft. lbs. (23 Nm).
     
    Engine oil and transmission oil level tubes
     
    Glow plug relay
     
    Air conditioning lines
     
    Air cleaner assembly
     
    Negative battery cable
     

  2.  
  3. Recharge air conditioning system.

    Click image to see an enlarged view

    Fig. Exploded view of the side intake manifold mounting-6.5L engines



    Click image to see an enlarged view

    Fig. Center intake manifold mounting-6.5L engines

  4.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Recover air conditioning system, and reposition air conditioning lines.
  4.  
  5. Remove or disconnect the following:
    WARNING
    Do not remove the center intake and side intakes as an assembly. Damage to the center intake and turbocharger may occur.



    Negative battery cable
     
    Air cleaner assembly
     
    Fuel lines, and electrical connections
     
    Engine and transmission oil level tubes
     



    Center intake assembly, and glow plug relay
     
    Side intake bolts and fuel retaining clips
     
    Side intakes
     

  6.  
  7. Clean all gaskets surface.
  8.  

To install:

  1. Install or connect the following:

    Side intakes and new gaskets. Torque the bolts to 31 ft. lbs. (42 Nm).
     
    Fuel lines retaining clips and electrical connection
     
    Center intake with new gaskets. Torque the bolts to 17 ft. lbs. (23 Nm).
     
    Engine oil and transmission oil level tubes
     
    Glow plug relay
     
    Air conditioning lines
     
    Air cleaner assembly
     
    Negative battery cable
     

  2.  
  3. Recharge air conditioning system.

    Click image to see an enlarged view

    Fig. Exploded view of the side intake manifold mounting-6.5L engines



    Click image to see an enlarged view

    Fig. Center intake manifold mounting-6.5L engines

  4.  

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
    NOTE
    Refer to Section 1 of this manual for the intake manifold torque sequence illustration. The illustration is located after the Torque Specification Chart.

  2.  
  3. Recover air conditioning system, and reposition air conditioning lines.
  4.  
  5. Remove or disconnect the following:
    WARNING
    Do not remove the center intake and side intakes as an assembly. Damage to the center intake and turbocharger may occur.



    Negative battery cable
     
    Air cleaner assembly
     
    Fuel lines, and electrical connections
     
    Engine and transmission oil level tubes
     



    Center intake assembly, and glow plug relay
     
    Side intake bolts and fuel retaining clips
     
    Side intakes
     

  6.  
  7. Clean all gaskets surface.
  8.  

To install:

  1. Install or connect the following:

    Side intakes and new gaskets. Torque the bolts to 31 ft. lbs. (42 Nm)
     
    Fuel lines retaining clips and electrical connection
     
    Center intake with new gaskets. Torque the bolts to 17 ft. lbs. (23 Nm)
     
    Engine oil and transmission oil level tubes
     
    Glow plug relay
     
    Air conditioning lines
     
    Air cleaner assembly
     
    Negative battery cable
     

  2.  
  3. Recharge air conditioning system.

    Click image to see an enlarged view

    Fig. Exploded view of the side intake manifold mounting-1998-00 6.5L engines



    Click image to see an enlarged view

    Fig. Center intake manifold mounting-1998-00 6.5L engines

  4.  

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
    NOTE
    Refer to Section 1 of this manual for the intake manifold torque sequence illustration. The illustration is located after the Torque Specification Chart.

  2.  
  3. Recover air conditioning system, and reposition air conditioning lines.
  4.  
  5. Remove or disconnect the following:
    WARNING
    Do not remove the center intake and side intakes as an assembly. Damage to the center intake and turbocharger may occur.



    Negative battery cable
     
    Air cleaner assembly
     
    Fuel lines, and electrical connections
     
    Engine and transmission oil level tubes
     



    Center intake assembly, and glow plug relay
     
    Side intake bolts and fuel retaining clips
     
    Side intakes
     

  6.  
  7. Clean all gaskets surface.
  8.  

To install:

  1. Install or connect the following:

    Side intakes and new gaskets. Torque the bolts to 31 ft. lbs. (42 Nm)
     
    Fuel lines retaining clips and electrical connection
     
    Center intake with new gaskets. Torque the bolts to 17 ft. lbs. (23 Nm)
     
    Engine oil and transmission oil level tubes
     
    Glow plug relay
     
    Air conditioning lines
     
    Air cleaner assembly
     
    Negative battery cable
     

  2.  
  3. Recharge air conditioning system.

    Click image to see an enlarged view

    Fig. Exploded view of the side intake manifold mounting-1998-00 6.5L engines



    Click image to see an enlarged view

    Fig. Center intake manifold mounting-1998-00 6.5L engines

  4.  

6.6L Engine

NOTE
This procedure is for replacement of the left or right intake manifold.

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove or disconnect the following:
    NOTE
    The intake manifold uses sealer. If necessary, pry at the area by the common rail bolt holes and be careful to avoid damaging the sealing surfaces.



    Batteries cables
     
    Turbocharger
     
    Fuel junction block
     
    Left or right fuel rail
     
    Intake manifold tube
     
    9 bolts and 2 nuts from the intake manifold. A bolt is located in the manifold opening.
     



    Intake manifold from the head. Cover the head openings to prevent debris from entering.
     

  6.  
  7. Clean all gaskets surface.
  8.  

To install:

  1. Install or connect the following:
    NOTE
    The left and right side manifolds are NOT interchangeable.



    A 1 / 8 in. (2-3mm) wide to 1 / 16 in (0.5-1.5mm) high bead of sealant to the sealing surface of the intake manifold
     



    Intake manifold
     
    Bolts and nuts. Tighten to 15 ft. lbs. (20 Nm), in sequence

    Click image to see an enlarged view

    Fig. Left side intake manifold bolt tightening sequence-6.6L engine



    Click image to see an enlarged view

    Fig. Right side intake manifold bolt tightening sequence-6.6L engine

     
    Intake manifold tube
     
    Fuel rail
     
    Fuel junction block
     
    Turbocharger
     
    Negative battery cables
     

  2.  
  3. Fill cooling system.
  4.  

Center Manifold
  1. Remove the Exhaust Gas Recirculation (EGR) valve cooler tube.
  2.  
  3. Remove the intake manifold tube.
  4.  
  5. Remove and discard the 2 intake manifold tube gaskets.
  6.  
  7. Remove the turbocharger.
  8.  
  9. Remove the center intake manifold bolts/nuts.
  10.  
  11. Pull-up the center intake manifold in order to remove.
  12.  
  13. Remove and discard the gaskets.
  14.  
  15. Clean the center intake manifold in cleaning solvent and air dry.
  16.  

To install:

  1. Install new center intake manifold gaskets.
  2.  
  3. Install the center intake manifold.
  4.  
  5. Install the center intake manifold bolts/nuts and tighten to 89 inch lbs. (10 Nm).
  6.  
  7. Install the turbocharger.
  8.  
  9. Install 2 new O-rings onto the intake manifold tube.
  10.  
  11. Lubricate the O-rings with clean engine oil to aid in the installation.
  12.  
  13. Install the intake manifold tube.
  14.  
  15. Install the EGR valve cooler tube.
  16.  

  1. Remove the Exhaust Gas Recirculation (EGR) valve cooler tube.
  2.  
  3. Remove the intake manifold tube.
  4.  
  5. Remove and discard the 2 intake manifold tube gaskets.
  6.  
  7. Remove the turbocharger.
  8.  
  9. Remove the center intake manifold bolts/nuts.
  10.  
  11. Pull-up the center intake manifold in order to remove.
  12.  
  13. Remove and discard the gaskets.
  14.  
  15. Clean the center intake manifold in cleaning solvent and air dry.
  16.  

To install:

Click image to see an enlarged view

Fig. Center intake manifold-6.6L engines

  1. Install new center intake manifold gaskets.
  2.  
  3. Install the center intake manifold.
  4.  
  5. Install the center intake manifold bolts/nuts and tighten to 89 inch lbs. (10 Nm).
  6.  
  7. Install the turbocharger.
  8.  
  9. Install 2 new O-rings onto the intake manifold tube.
  10.  
  11. Lubricate the O-rings with clean engine oil to aid in the installation.
  12.  
  13. Install the intake manifold tube.
  14.  
  15. Install the EGR valve cooler tube.
  16.  

  1. Remove the Exhaust Gas Recirculation (EGR) valve cooler tube.
  2.  
  3. Remove the intake manifold tube.
  4.  
  5. Remove and discard the 2 intake manifold tube gaskets.
  6.  
  7. Remove the turbocharger.
  8.  
  9. Remove the center intake manifold bolts/nuts.
  10.  
  11. Pull-up the center intake manifold in order to remove.
  12.  
  13. Remove and discard the gaskets.
  14.  
  15. Clean the center intake manifold in cleaning solvent and air dry.
  16.  

To install:

Click image to see an enlarged view

Fig. Center intake manifold-6.6L engines

  1. Install new center intake manifold gaskets.
  2.  
  3. Install the center intake manifold.
  4.  
  5. Install the center intake manifold bolts/nuts and tighten to 89 inch lbs. (10 Nm).
  6.  
  7. Install the turbocharger.
  8.  
  9. Install 2 new O-rings onto the intake manifold tube.
  10.  
  11. Lubricate the O-rings with clean engine oil to aid in the installation.
  12.  
  13. Install the intake manifold tube.
  14.  
  15. Install the EGR valve cooler tube.
  16.  

Left & Right Manifolds
  1. Drain the cooling system.
  2.  
  3. Remove or disconnect the following:
    NOTE
    The intake manifold uses sealer. If necessary, pry at the area by the common rail bolt holes and be careful to avoid damaging the sealing surfaces.



    Batteries cables
     
    Center intake manifold
     
    Fuel junction block
     
    Left or right fuel rail
     
    Intake manifold tube
     
    9 bolts and 2 nuts from the intake manifold. A bolt is located in the manifold opening.
     



    Intake manifold from the head. Cover the head openings to prevent debris from entering.
     

  4.  
  5. Clean all gaskets surface.
  6.  

To install:

  1. Install or connect the following:
    NOTE
    The left and right side manifolds are NOT interchangeable.



    A 1 / 8 in. (2-3mm) wide to 1 / 16 in (0.5-1.5mm) high bead of sealant to the sealing surface of the intake manifold
     



    Intake manifold
     
    Bolts and nuts. Tighten to 15 ft. lbs. (20 Nm), in sequence.

    Click image to see an enlarged view

    Fig. Left side intake manifold bolt tightening sequence-6.6L engines



    Click image to see an enlarged view

    Fig. Right side intake manifold bolt tightening sequence-6.6L engines

     
    Intake manifold tube
     
    Fuel rail
     
    Fuel junction block
     
    Turbocharger
     
    Negative battery cables
     

  2.  
  3. Fill cooling system.
  4.  

  1. Drain the cooling system.
  2.  
  3. Remove or disconnect the following:
    NOTE
    The intake manifold uses sealer. If necessary, pry at the area by the common rail bolt holes and be careful to avoid damaging the sealing surfaces.



    Batteries cables
     
    Center intake manifold
     
    Fuel junction block
     
    Left or right fuel rail
     
    Intake manifold tube
     
    9 bolts and 2 nuts from the intake manifold. A bolt is located in the manifold opening.
     



    Intake manifold from the head. Cover the head openings to prevent debris from entering.
     

  4.  
  5. Clean all gaskets surface.
  6.  

To install:

  1. Install or connect the following:
    NOTE
    The left and right side manifolds are NOT interchangeable.



    A 1 / 8 in. (2-3mm) wide to 1 / 16 in (0.5-1.5mm) high bead of sealant to the sealing surface of the intake manifold
     



    Intake manifold
     
    Bolts and nuts. Tighten to 15 ft. lbs. (20 Nm), in sequence.

    Click image to see an enlarged view

    Fig. Left side intake manifold bolt tightening sequence-6.6L engines



    Click image to see an enlarged view

    Fig. Right side intake manifold bolt tightening sequence-6.6L engines

     
    Intake manifold tube
     
    Fuel rail
     
    Fuel junction block
     
    Turbocharger
     
    Negative battery cables
     

  2.  
  3. Fill cooling system.
  4.  

Left And Right Manifolds
  1. Drain the cooling system.
  2.  
  3. Remove or disconnect the following:
    NOTE
    The intake manifold uses sealer. If necessary, pry at the area by the common rail bolt holes and be careful to avoid damaging the sealing surfaces.



    Batteries cables
     
    Center intake manifold
     
    Fuel junction block
     
    Left or right fuel rail
     
    Intake manifold tube
     
    9 bolts and 2 nuts from the intake manifold. A bolt is located in the manifold opening.
     



    Intake manifold from the head. Cover the head openings to prevent debris from entering.
     

  4.  
  5. Clean all gaskets surface.
  6.  

To install:

  1. Install or connect the following:
    NOTE
    The left and right side manifolds are NOT interchangeable.



    A 1 / 8 in. (2-3mm) wide to 1 / 16 in (0.5-1.5mm) high bead of sealant to the sealing surface of the intake manifold
     



    Intake manifold
     
    Bolts and nuts. Tighten to 15 ft. lbs. (20 Nm), in sequence.

    Click image to see an enlarged view

    Fig. Left side intake manifold bolt tightening sequence-6.6L engine



    Click image to see an enlarged view

    Fig. Right side intake manifold bolt tightening sequence-6.6L engine

     
    Intake manifold tube
     
    Fuel rail
     
    Fuel junction block
     
    Turbocharger
     
    Negative battery cables
     

  2.  
  3. Fill cooling system.
  4.  

 
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