Canyon, Colorado 2006-2007

Cylinder Head

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Removal & Installation



The following tools are required:



EN-48464-Lower Timing Gear Tensioner Holding Tool
 
EN-46547-Flywheel Holding Tool (LK5 or L52 Engine Only)
 
J 44221-Camshaft Holding Tool
 
J 45059-Torque Angle Meter
 
TDC Indicator Tool (Some models may use a dial Indicator or graduation marks on the side of a sliding shaft for visual indication)
 

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Install protective covering to the front of the vehicle. This is to protect the grille from damage.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove the air cleaner resonator, the outlet duct and the air cleaner assembly.
  8.  
  9. Disconnect the negative battery cable. Remove the battery from the vehicle.
  10.  
  11. Disconnect the Fuel/EVAP lines from the intake manifold and move aside (includes fuel line removal from fuel rail).
  12.  
  13. Remove the bolt holding the oil indicator (dipstick) tube to the intake manifold and move the oil dipstick aside. Do not remove.
  14.  
  15. Drain and recycle the engine coolant.
  16.  
  17. Raise and safely support the vehicle securely.
  18.  
  19. Remove the bolts holding the engine shield (2.8L or 3.5L).
  20.  
  21. Remove the engine shield from the vehicle (2.8L or 3.5L).
  22.  
  23. Remove the bolts holding the oil pan skid plate (2.8L or 3.5L).
  24.  
  25. Remove the oil pan skid plate from the vehicle (2.8L or 3.5L).
  26.  
  27. Remove or disconnect the following:

    Drive belt
     
    Engine oil
     
    Left front tire and wheel
     
    Left front wheelhouse panel
     
    Fir tree wiring harness connectors from the engine wiring harness bracket from the left front wheelhouse opening
     
    From the left front wheelhouse, the engine wiring harness bracket from the engine and set aside. It may be necessary to loosen the fasteners on the frame rail (3.7L).
     
    Intake manifold bolts from the wheelhouse access (bolts stay with intake manifold). On two-wheel drive vehicles, the intake manifold bolts are removed from the top of the engine, not through the left front wheelhouse panel.
     

  28.  
  29. Lower the vehicle.
  30.  
  31. Remove or disconnect the following:
    CAUTION
    Before performing the TDC procedures, break loose both the exhaust and intake camshaft sprocket bolts. Use a 1 inch (25 mm) open end wrench on the camshaft hexs to hold the camshaft from turning. Do not remove the bolts.



    PCV pipes from the cam cover and remove the intake manifold from the vehicle. PCM engine harness connectors from the PCM (LL8 Engine Only). PCM from the intake manifold bracket (3.7L)
     
    Generator output battery terminal nut
     
    Generator lead from the generator
     
    Generator electrical connector
     
    Generator bolts and set the generator aside. The generator does not have to be removed from the vehicle. On a two-wheel drive vehicle, the generator must be removed from the vehicle.
     
    A/C pipe clamp from the engine lift hook bracket
     
    Engine lift hook bracket bolts and bracket from the vehicle
     
    P/S pump bolts and reposition the pump (3.7L)
     
    Bolts holding the windshield washer solvent container and coolant recovery reservoir to the right inner fender. Move aside to gain access to the engine wiring harness to PCM (2.8L or 3.5L).
     
    PCM engine wiring harness connector
     
    Engine Coolant Temperature Sensor wiring harness connector
     
    MAP Sensor wiring harness connector
     
    Ignition Coils wiring harness connector
     
    Harness clamps at power steering pump wiring harness connector
     
    Wiring Harness fastener at right front inner fender
     
    Throttle Body wiring harness connector
     
    Camshaft Sensors wiring harness connector
     
    Exhaust Camshaft Actuator wiring harness connector
     
    Fuel Injectors wiring harness connectors
     
    HO2S No. 1 wiring harness connectors
     
    Set aside the cross-vehicle engine wiring harness on the left side of the vehicle
     
    A.I.R. injection pipe block-off plate bolts from the cylinder head
     
    A.I.R. injection pipe block-off plate
     
    Bolts from the exhaust manifold heat shield
     
    Exhaust manifold back and away from the cylinder head
     
    Bolts to all ignition coil assemblies and remove all ignition coil assemblies from the cam cover
     
    All the spark plugs from the cylinder head
     
    Ground strap bolt (3.7L)
     
    Cam cover bolts
     
    Cam cover from the cylinder head
     
    Upper radiator hose and clamp from the cylinder head
     

  32.  
  33. Rotate the engine clockwise by hand to TDC on the compression stroke by using a piston TDC indicator tool and/or dial indicator in the number 1 cylinder. The TDC indicator tool graduation marks on the shaft should note top of the piston stroke. When the piston is at TDC, the flats at the rear of the camshafts will be facing up and flat when using a straight edge across the camshaft flats. There may be a variation of build and the straight edge may not lay perfectly flat across back of the camshafts.
    CAUTION
    Do not rotate the engine counterclockwise to find TDC, as this will put slack in the camshaft actuator and the timing chain. If the engine is rotated counterclockwise, even a small amount, then the engine should be rotated at least 90 degrees and then brought back to TDC by rotating clockwise only.


    CAUTION
    The word Delphi on the exhaust camshaft position actuator will be parallel with the cylinder head to cam cover mating surface. When the piston is at TDC, the flats at the rear of the camshafts will be facing up.

  34.  
  35. Once TDC is located for the number 1 cylinder using above method, raise the vehicle and lock the flywheel with tool EN-46547-Flywheel Holding Tool (2.8L or 3.5L).
  36.  
  37. Use a metal scribe or equivalent to place a reference mark on the harmonic balancer to the front cover for alignment purposes.
  38.  
  39. Lower the vehicle.
    CAUTION
    The camshaft holding tools must be installed on the camshafts to prevent camshaft rotation. When performing service to the valve train and/or timing components, valve spring pressure can cause the camshafts to rotate unexpectedly and can cause personal injury.


    CAUTION
    If the timing is correct (TDC compression stroke number 1 cylinder), the camshaft flats will be in the up position.

  40.  
  41. Install the J 44221- Camshaft Holding Tool to the back of the camshafts.
  42.  
  43. Remove the upper timing chain guide from the cylinder head (not found on later vehicles).
    CAUTION
    The exhaust camshaft actuator must be fully advanced before scribing your reference mark on both timing gear sprockets and the timing chain to mark location prior to disassembly. There may be some normal play in the exhaust camshaft actuator itself. To ensure camshaft actuator is fully advanced, do not rotate engine counterclockwise when finding TDC No. 1.

  44.  
  45. Clean the timing chain and gears with Brake Cleaner or suitable solvent. Use a metal scribe or equivalent to place a reference mark on both timing gear sprockets and the timing chain to mark the location prior to disassembly. It is recommended that a metal scribe or equivalent be in the twelve -o-clock position.
    CAUTION
    Do not use excessive force to seat the wedge tool. If excessive force is used, you may damage the timing chain tensioner or break the front cover bolt requiring complete disassembly of the front engine.

  46.  
  47. Install EN-48464-Lower Timing Chain Tensioner Holding Tool. This wedge tool will hold the timing chain and tensioner in position. It is important to install the tool with the proper orientation and to ensure that it is seated square against the timing chain and against the timing cover center bolt. The narrow ramp of the wedge tool needs to be placed so that it faces the timing chain. The wedge tool should be lightly seated using a couple of very light taps with a small plastic or brass hammer.

    Click image to see an enlarged view

    Fig. Installing -48464-Lower Timing Chain Tensioner Holding Tool



    Click image to see an enlarged view

    Fig. Placing the narrow ramp of the wedge tool so that it faces the timing chain

  48.  
  49. Once the tool is correctly installed, unscrew the handle and remove the handle.
  50.  
  51. Remove (1 long and 2 short ) cylinder head bolts next to the exhaust and intake timing chain tensioner shoes and discard the bolts.
    CAUTION
    Use a 25 mm (1 inch) open end wrench on the camshaft hexs to hold the camshaft from turning. It is critical that the crankshaft does not move and is held at TDC when the intake and exhaust camshaft sprocket bolts are removed.


    CAUTION
    If the crankshaft is not held in place, the wedge tool could be dislodged. If the crankshaft moves, or if the tool is not seated properly allowing the timing chain tensioner to extend, the repair will have to be completed by removing the front cover to release the timing chain tensioner.

  52.  
  53. Remove both upper cylinder head access hole plugs from the front of the cylinder head.
  54.  
  55. Remove both upper timing chain tensioner shoe bolts.
  56.  
  57. Remove the exhaust and the intake camshaft sprocket bolts. Discard the bolts.
  58.  
  59. Carefully remove the exhaust and intake camshaft sprockets from the exhaust and intake camshafts while still engaged with the timing chain. Refer to the above illustration. The above illustration shows the exhaust camshaft sprocket already removed.
  60.  
  61. Remove the sprockets from the chain. Tie a piece of mechanics wire on the timing chain and let it drop.
  62.  
  63. Remove the cylinder head bolts from the cylinder head. Before removing the cylinder head bolts, use a drift punch and hammer to shock the bolts. This will ensure that the cylinder head bolts will not strip out the threads in the engine block or break. Once the bolts are removed, discard them.
  64.  
  65. Remove the AIR pump bolt and fir tree fastener from the back of the cylinder head.
  66.  
  67. Remove the cylinder head from the vehicle.
  68.  

To install:

Click image to see an enlarged view

Fig. Cylinder head bolt torque sequence-2.8L and 2.9Lengines



Click image to see an enlarged view

Fig. Cylinder head bolt torque sequence-3.5L and 3.7L engines


CAUTION
A new service cylinder head assembly with valves is available for 3.5L only.


CAUTION
Install the cylinder head without the camshafts.

  1. Install the engine cylinder head to the engine block.
  2.  
  3. Install the AIR pump bolt and fir tree fastener from the back of the cylinder head.
  4.  
  5. Install new cylinder head bolts and tighten the bolts.
    CAUTION
    The camshaft holding tools must be installed on the camshafts to prevent camshaft rotation. When performing service to the valve train and/or timing components, valve spring pressure can cause the camshafts to rotate unexpectedly and can cause personal injury.


    CAUTION
    Before installing the camshafts, Clean and inspect the gasket mounting surfaces.

  6.  
  7. Install the camshafts with the flats up using the J 44221-Camshaft Holding Tool.
    NOTE
    Tension must be always kept on the intake side of the timing chain to properly keep the engine in time. If the chain is loose the timing will be off, which may cause internal engine damage or set DTC P0017.


    NOTE
    Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


    NOTE
    The exhaust camshaft actuator must be fully advanced during installation. Engine damage may occur if the camshaft actuator is not fully advanced.


    CAUTION
    To aid in aligning the actuator to the camshaft, use a 1 inch (25 mm) open end wrench on the hex of the camshaft to rotate. This will ensure the alignment pin is properly engaged with the camshaft and hand tighten the new exhaust camshaft sprocket bolt.

  8.  
  9. Install the exhaust camshaft actuator/sprocket and chain onto the exhaust camshaft. Use scribe marks as an alignment guide.
    CAUTION
    To aid in aligning the actuator to the camshaft, use a 1 inch (25 mm) open end wrench on the hex of the camshaft to rotate. This will ensure the alignment pin is properly engaged with the camshaft and hand tighten the new exhaust camshaft sprocket bolt.

  10.  
  11. Install the intake camshaft sprocket and chain onto the intake camshaft. Use scribe marks as alignment guide.
  12.  
  13. Tighten the new intake camshaft sprocket bolt to 15 ft. lbs. (20 Nm). Use the J 45059-Torque Angle Meter to rotate the intake camshaft sprocket bolt an additional 100 degrees.
  14.  
  15. Tighten the new exhaust camshaft actuator sprocket bolt to 18 ft. lbs. (25 Nm). Use the J 45059-Torque Angle Meter to rotate the exhaust camshaft actuator sprocket bolt an additional 135 degrees.
  16.  
  17. Install both upper timing chain tensioner shoe bolts to 18 ft. lbs. (25 Nm).
  18.  
  19. Install both upper cylinder head access hole plugs to the front of the cylinder head. Tighten the plugs to 44 inch lbs. (5 Nm).
  20.  
  21. Lift the vehicle and remove the EN-46547-Flywheel Holding Tool (LK5 or L52 Engine Only).
  22.  
  23. Lower the vehicle.
  24.  
  25. Remove the J 44221-Camshaft Holding Tool from the back of the camshafts.
    NOTE
    Ensure that the wedge tool is removed from the engine prior to rotation. If the wedge tool is not removed, engine damage will result.

  26.  
  27. Install the handle of the EN-48464-Lower Timing Chain Tensioner Holding Tool and remove the wedge portion of the tool from the engine.
    CAUTION
    It is critical that the engine is at TDC and not a couple of degrees off. If in doubt, repeat this following step.

  28.  
  29. Rotate the engine clockwise by hand two complete revolutions to TDC No. 1 on the compression stroke. Refer to removal procedure. If you go past TDC, rotate the engine back approximately 45 degrees before TDC and then rotate clockwise up to TDC to ensure that the timing chain is tight (no slack) between the crank sprocket and the timing gears.
    CAUTION
    Do not use the J 44221-Camshaft Holding Tool , installed to the back of the camshafts, as a method to verify timing.

  30.  
  31. Both intake and exhaust camshaft flats should be facing up and flat with the cylinder head. If the J 44221-Camshaft Holding Tool is used to verify cam timing, you could be off approximately one tooth and cause DTC P0017 to set. If a worn or new J 44221-Camshaft Holding Tool is used to verify timing, the timing will be off.
  32.  
  33. To verify timing, set a straight edge across the flats of the camshafts. Both camshaft flats should be flat. there may be some variation of build and the straight edge may not lay perfectly flat across back of the camshafts. If one or both camshaft flats are off, then the timing is off. Repeat step 15 and recheck. If the camshaft flats are still not flat, the camshaft timing will have to be reset. This may require removal and reinstallation of one or both camshaft sprockets. Refer to removal procedure.
  34.  
  35. Install (1 long and 2 short ) cylinder head bolts next to the exhaust and intake timing chain tensioner shoes and tighten the bolts. Refer to Cylinder Head Replacement.
  36.  
  37. Position the upper timing chain guide to the cylinder head. Apply threadlocker (P/N 8902129), to the upper timing chain guide bolt threads.
  38.  
  39. Install the upper timing chain guide bolts and tighten to 89 inch lbs. (10 Nm).
  40.  
  41. Install the upper radiator hose and clamp to the cylinder head.
  42.  
  43. Clean and inspect the camshaft cover.
  44.  
  45. Install a new camshaft cover seal and new ignition control module seals to the cam cover. Position the camshaft cover to the cylinder head.
  46.  
  47. Install the camshaft cover bolts and tighten to 89 inch lbs. (10 Nm).
  48.  
  49. Check the gap on all of the spark plugs. The gap should be 0.042 inches (1.08 mm). Tighten all of the spark plugs to 13 ft lbs. (18 Nm).
  50.  
  51. Install the ignition coils into the camshaft cover.
  52.  
  53. Install the ignition coil bolts and tighten to 89 inch lbs. (10 Nm).
  54.  
  55. Reposition the exhaust manifold to the cylinder head and install the exhaust manifold bolts to the cylinder head.
  56.  
  57. Install a new A.I.R. injection gasket, then the cover and pipe studs to the cylinder head. Tighten the pipe studs to 18 ft. lbs. (25 Nm).
  58.  
  59. Install ground strap to cylinder head to exhaust manifold (3.7L).
  60.  
  61. Install the exhaust manifold heat shield to the exhaust manifold.
  62.  
  63. Apply anti-seize, GM P/N 12371386, to the exhaust manifold heat shield nuts.
  64.  
  65. Install the exhaust manifold heat shield nuts and tighten 89 inch lbs. (10 Nm).
  66.  
  67. Install the intake manifold to the cylinder head. Raise the vehicle and install the blind intake manifold bolts from the left front wheelhouse access.
  68.  
  69. Reposition the engine wiring harness bracket to the engine and harnesses. Install the engine wiring harness bracket bolts. Tighten the bracket bolts to 89 inch lbs. (10 Nm).
  70.  
  71. Install the left front wheelhouse panel. Install the left wheel and tire.
  72.  
  73. Refill the engine oil.
  74.  
  75. Install the lower radiator hose if removed.
  76.  
  77. Install the oil pan skid plate (2.8L or 3.5L).
  78.  
  79. Install the engine shield (2.8L or 3.5L).
  80.  
  81. Lower the vehicle.
  82.  
  83. Install the cross-vehicle wiring harness connectors to the following components:

    PCM
     




    1. PCM engine harness connectors from PCM (3.7L)
    2.  
    3. PCM from intake manifold Bracket (3.7L)

      Map Sensor
       
      Ignition Coils
       
      Harness clamps at power steering pump
       
      Wiring harness fastener at right front inner fender
       
      Throttle Body
       
      Camshaft Sensors
       
      Exhaust Camshaft Actuator
       
      Fuel Injectors
       
      HO2S No. 1
       

    4.  

  84.  
  85. Install the windshield washer solvent container and coolant recovery reservoir bolts to the right inner fender (2.8L or 3.5L). Tighten the bolts to 89 inch lbs. (10 Nm).
  86.  
  87. Install the PCV pipes to the intake manifold.
  88.  
  89. Reposition the oil indicator (dipstick) tube and tighten the bolt to the intake manifold.
  90.  
  91. Reposition the Fuel/EVAP lines to the intake manifold retainer.
  92.  
  93. Install the following components.

    Power steering pump bolts
     
    Generator
     
    A/C compressor hose/pipe bracket clamp for the engine lift bracket.
     
    Drive Belt
     

  94.  
  95. Install the battery (2.8L or 3.5L).
  96.  
  97. Install the negative battery cable (3.7L).
  98.  
  99. Install the air induction assembly.
  100.  
  101. Refill with new engine oil.
  102.  
  103. Refill with new coolant.
  104.  
  105. Install the air cleaner resonator, the outlet duct and the air cleaner assembly.
  106.  
  107. Remove the fender covers.
  108.  
  109. Remove the protective covering from the front of the vehicle.
  110.  
  111. Install the scan tool and start the engine.
  112.  
  113. Check for DTC-s
  114.  
  115. Road test the vehicle. DTC P0017 is a Type B diagnostic code. Three consecutive ignition key cycles must be performed during the road test with a minimum of a one minute run time between key cycles to verify that a DTC P0017 did not set.
  116.  

 
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