Infiniti Car 1998-05

Cylinder Head 3

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Removal & Installation



4.1L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Drain the engine oil.
  8.  
  9. Remove or disconnect the following:

    Both battery cables
     
    Engine assembly from the vehicle and place it on a workstand
     
    Exhaust manifold
     
    Drain plugs on the sides of the engine and drain the coolant
     
    Intake manifold collector
     
    Ignition coil sub-harness
     
    Ignition coils
     
    Spark plugs
     
    Fuel rail with injectors. Do not disassemble the fuel hose.
     
    Intake manifold
     
    Rocker arm covers and bring the No. 1 piston to Top Dead Center (TDC) on the compression stroke
     
    Camshaft Position (CMP) sensor
     
    Right and left upper front covers. Be sure to remove the bolts in the correct sequence to prevent damage to the cover.
     


    Click image to see an enlarged view

    Fig. Upper front cover bolt removal sequence-4.1L engine, right bank



    Click image to see an enlarged view

    Fig. Upper front cover bolt removal sequence-4.1L engine, left bank

    Upper chain tensioners
     

  10.  
  11. Apply paint marks on the upper timing chains, camshaft and idler sprockets so they can be installed in their original positions.

    Camshaft sprocket
     
    Idler sprocket bolt
     
    Cylinder head sub-bolts. The bolts are different lengths, note their differences so they can be installed in their original positions.
     

  12.  
  13. Loosen the cylinder head bolts gradually in the proper removal sequence, then remove the cylinder head.
  14.  


    Click image to see an enlarged view

    Fig. Be sure to install the long bolts in the positions indicated by the arrows-4.1L engine


To install:

  1. Be sure all mating surfaces are clean before installation.
  2.  
  3. Check the cylinder head surface for warpage using a feeler gauge and a suitable straightedge. If the cylinder head is warped more than 0.004 in. (0.1mm), it must be resurfaced or replaced. The total amount machined from the head or head and block combined, cannot total more than 0.008 in. (0.2mm).
  4.  
  5. Place new gaskets on the cylinder block.
  6.  
  7. Be sure the knock pins on the camshafts are in the positions shown. Carefully place the cylinder heads on the engine. Do not damage the head gasket.
  8.  
  9. Lubricate the cylinder head bolt threats and seat surfaces with engine oil. Torque the bolts in sequence using the following sub-steps:
    1. Step 1: 22 ft. lbs. (29 Nm).
    2.  
    3. Step 2: 69 ft. lbs. (93 Nm).
    4.  
    5. Step 3: loosen the bolts completely.
    6.  
    7. Step 4: 18-25 ft. lbs. (25-35 Nm).
    8.  
    9. Step 5: Plus 90-95°.
    10.  

  10.  
  11. Install or connect the following:

    Cylinder head sub-bolts. Torque the bolts to 56-74 inch lbs. (6-8 Nm). Be sure the long bolts are returned to the positions shown.
     
    Idler and camshaft sprockets
     
    Chain tensioners
     

  12.  
  13. Using new gaskets, install the cylinder head covers. Be sure to apply RTV silicone sealant to the gasket arch and rubber plugs.
  14.  
  15. Torque the cylinder head cover bolts in sequence using the following sub-steps:
    1. Step 1: Nos. 1 through 16: 35-52 inch lbs. (4-6 Nm).
    2.  
    3. Step 2: Nos. 1 through 16: 61-78 inch lbs. (7-9 Nm).
    4.  
    5. Step 3: Nos. 1 and 2: 61-78 inch lbs. (7-9 Nm).
    6.  

  16.  
  17. Install or connect the following:

    Intake valve timing control solenoid with a new O-ring. Torque the solenoid to 18-25 ft. lbs. (25-34 Nm).
     

  18.  
  19. Apply a bead of RTV silicone sealant to the upper front covers, then install them. Torque the bolts to 56-74 inch lbs. (6-8 Nm).

    CMP sensor
     
    Rocker arm covers
     
    Intake manifold with new gaskets
     
    Fuel rail and injectors
     
    Spark plugs and ignition coils
     
    Intake manifold collector
     
    Exhaust manifold with new gaskets
     
    Engine assembly to the vehicle
     
    Battery and cables
     



    Click image to see an enlarged view

    Fig. Torque the upper front cover bolts in the sequence shown-4.1L engine

  20.  
  21. Fill and bleed the cooling system.
  22.  
  23. Fill the engine with clean oil.
  24.  
  25. Start the vehicle, check for leaks and repair if necessary.
  26.  


    Click image to see an enlarged view

    Fig. Be sure to position the camshaft knock pins as shown before installing the cylinder heads-4.1L engine



    Click image to see an enlarged view

    Fig. Cylinder head torque sequence-4.1L engine



    Click image to see an enlarged view

    Fig. Cylinder head cover bolt tightening sequence-4.1L engine


  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:
  4.  
  5. Properly relieve the fuel system pressure.
  6.  
  7. Drain the cooling system.
  8.  
  9. Drain the engine oil.

    Both battery cables
     
    Engine assembly from the vehicle and place it on a workstand
     
    Exhaust manifold
     
    Drain plugs on the sides of the engine and drain the coolant
     
    Intake manifold collector
     
    Ignition coil sub-harness
     
    Ignition coils
     
    Spark plugs
     
    Fuel rail with injectors. Do not disassemble the fuel hose
     
    Intake manifold
     
    Rocker arm covers and bring the No. 1 piston to Top Dead Center (TDC) on the compression stroke
     
    Camshaft Position (CMP) sensor
     
    Right and left upper front covers. Be sure to remove the bolts in the correct sequence to prevent damage to the cover

    Click image to see an enlarged view

    Fig. Upper front cover bolt removal sequence-4.1L engine, right bank



    Click image to see an enlarged view

    Fig. Upper front cover bolt removal sequence-4.1L engine, left bank

     
    Upper chain tensioners
     

  10.  
  11. Apply paint marks on the upper timing chains, camshaft and idler sprockets so they can be installed in their original positions.

    Camshaft sprocket
     
    Idler sprocket bolt
     
    Cylinder head sub-bolts. The bolts are different lengths, note their differences so they can be installed in their original positions

    Click image to see an enlarged view

    Fig. Be sure to install the long bolts in the positions indicated by the arrows-4.1L engine

     

  12.  
  13. Loosen the cylinder head bolts gradually in the proper removal sequence, then remove the cylinder head.
  14.  

To install:

  1. Be sure all mating surfaces are clean before installation.
  2.  
  3. Check the cylinder head surface for warpage using a feeler gauge and a suitable straightedge. If the cylinder head is warped more than 0.004 in. (0.1mm), it must be resurfaced or replaced. The total amount machined from the head or head and block combined, cannot total more than 0.008 in. (0.2mm).
  4.  
  5. Place new gaskets on the cylinder block.
  6.  
  7. Be sure the knock pins on the camshafts are in the positions shown. Carefully place the cylinder heads on the engine. Do not damage the head gasket.

    Click image to see an enlarged view

    Fig. Be sure to position the camshaft knock pins as shown before installing the cylinder heads-4.1L engine



    Click image to see an enlarged view

    Fig. Cylinder head torque sequence-4.1L engine

  8.  
  9. Lubricate the cylinder head bolt threats and seat surfaces with engine oil. Torque the bolts in sequence using the following sub-steps:
    1. Step 1: 22 ft. lbs. (29 Nm).
    2.  
    3. Step 2: 69 ft. lbs. (93 Nm).
    4.  
    5. Step 3: loosen the bolts completely.
    6.  
    7. Step 4: 18-25 ft. lbs. (25-35 Nm).
    8.  
    9. Step 5:Plus 90-95°.
    10.  

  10.  
  11. Install or connect the following:

    Cylinder head sub-bolts. Torque the bolts to 56-74 inch lbs. (6-8 Nm). Be sure the long bolts are returned to the positions shown.
     
    Idler and camshaft sprockets
     
    Chain tensioners
     

  12.  
  13. Using new gaskets, install the cylinder head covers. Be sure to apply RTV silicone sealant to the gasket arch and rubber plugs.
  14.  
  15. Torque the cylinder head cover bolts in sequence using the following sub-steps:
    1. Step 1: Nos. 1 through 16: 35-52 inch lbs. (4-6 Nm).
    2.  
    3. Step 2: Nos. 1 through 16: 61-78 inch lbs. (7-9 Nm).
    4.  
    5. Step 3: Nos. 1 and 2: 61-78 inch lbs. (7-9 Nm).

      Click image to see an enlarged view

      Fig. Cylinder head cover bolt tightening sequence-4.1L engine

    6.  

  16.  
  17. Install or connect the following:

    Intake valve timing control solenoid with a new O-ring. Torque the solenoid to 18-25 ft. lbs. (25-34 Nm)
     

  18.  
  19. Apply a bead of RTV silicone sealant to the upper front covers, then install them. Torque the bolts to 56-74 inch lbs. (6-8 Nm).

    Click image to see an enlarged view

    Fig. Torque the upper front cover bolts in the sequence shown-4.1L engine



    CMP sensor
     
    Rocker arm covers
     
    Intake manifold with new gaskets
     
    Fuel rail and injectors
     
    Spark plugs and ignition coils
     
    Intake manifold collector
     
    Exhaust manifold with new gaskets
     
    Engine assembly to the vehicle
     
    Battery and cables
     

  20.  
  21. Fill and bleed the cooling system.
  22.  
  23. Fill the engine with clean oil.
  24.  
  25. Start the vehicle, check for leaks and repair if necessary.
  26.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:
  4.  
  5. Properly relieve the fuel system pressure.
  6.  
  7. Drain the cooling system.
  8.  
  9. Drain the engine oil.

    Both battery cables
     
    Engine assembly from the vehicle and place it on a workstand
     
    Exhaust manifold
     
    Drain plugs on the sides of the engine and drain the coolant
     
    Intake manifold collector
     
    Ignition coil sub-harness
     
    Ignition coils
     
    Spark plugs
     
    Fuel rail with injectors. Do not disassemble the fuel hose
     
    Intake manifold
     
    Rocker arm covers and bring the No. 1 piston to Top Dead Center (TDC) on the compression stroke
     
    Camshaft Position (CMP) sensor
     
    Right and left upper front covers. Be sure to remove the bolts in the correct sequence to prevent damage to the cover

    Click image to see an enlarged view

    Fig. Upper front cover bolt removal sequence-4.1L engine, right bank



    Click image to see an enlarged view

    Fig. Upper front cover bolt removal sequence-4.1L engine, left bank

     
    Upper chain tensioners
     

  10.  
  11. Apply paint marks on the upper timing chains, camshaft and idler sprockets so they can be installed in their original positions.

    Camshaft sprocket
     
    Idler sprocket bolt
     
    Cylinder head sub-bolts. The bolts are different lengths, note their differences so they can be installed in their original positions

    Click image to see an enlarged view

    Fig. Be sure to install the long bolts in the positions indicated by the arrows-4.1L engine

     

  12.  
  13. Loosen the cylinder head bolts gradually in the proper removal sequence, then remove the cylinder head.
  14.  

To install:

  1. Be sure all mating surfaces are clean before installation.
  2.  
  3. Check the cylinder head surface for warpage using a feeler gauge and a suitable straightedge. If the cylinder head is warped more than 0.004 in. (0.1mm), it must be resurfaced or replaced. The total amount machined from the head or head and block combined, cannot total more than 0.008 in. (0.2mm).
  4.  
  5. Place new gaskets on the cylinder block.
  6.  
  7. Be sure the knock pins on the camshafts are in the positions shown. Carefully place the cylinder heads on the engine. Do not damage the head gasket.

    Click image to see an enlarged view

    Fig. Be sure to position the camshaft knock pins as shown before installing the cylinder heads-4.1L engine



    Click image to see an enlarged view

    Fig. Cylinder head torque sequence-4.1L engine

  8.  
  9. Lubricate the cylinder head bolt threats and seat surfaces with engine oil. Torque the bolts in sequence using the following sub-steps:
    1. Step 1: 22 ft. lbs. (29 Nm).
    2.  
    3. Step 2: 69 ft. lbs. (93 Nm).
    4.  
    5. Step 3: loosen the bolts completely.
    6.  
    7. Step 4: 18-25 ft. lbs. (25-35 Nm).
    8.  
    9. Step 5:Plus 90-95°.
    10.  

  10.  
  11. Install or connect the following:

    Cylinder head sub-bolts. Torque the bolts to 56-74 inch lbs. (6-8 Nm). Be sure the long bolts are returned to the positions shown.
     
    Idler and camshaft sprockets
     
    Chain tensioners
     

  12.  
  13. Using new gaskets, install the cylinder head covers. Be sure to apply RTV silicone sealant to the gasket arch and rubber plugs.
  14.  
  15. Torque the cylinder head cover bolts in sequence using the following sub-steps:
    1. Step 1: Nos. 1 through 16: 35-52 inch lbs. (4-6 Nm).
    2.  
    3. Step 2: Nos. 1 through 16: 61-78 inch lbs. (7-9 Nm).
    4.  
    5. Step 3: Nos. 1 and 2: 61-78 inch lbs. (7-9 Nm).

      Click image to see an enlarged view

      Fig. Cylinder head cover bolt tightening sequence-4.1L engine

    6.  

  16.  
  17. Install or connect the following:

    Intake valve timing control solenoid with a new O-ring. Torque the solenoid to 18-25 ft. lbs. (25-34 Nm)
     

  18.  
  19. Apply a bead of RTV silicone sealant to the upper front covers, then install them. Torque the bolts to 56-74 inch lbs. (6-8 Nm).

    Click image to see an enlarged view

    Fig. Torque the upper front cover bolts in the sequence shown-4.1L engine



    CMP sensor
     
    Rocker arm covers
     
    Intake manifold with new gaskets
     
    Fuel rail and injectors
     
    Spark plugs and ignition coils
     
    Intake manifold collector
     
    Exhaust manifold with new gaskets
     
    Engine assembly to the vehicle
     
    Battery and cables
     

  20.  
  21. Fill and bleed the cooling system.
  22.  
  23. Fill the engine with clean oil.
  24.  
  25. Start the vehicle, check for leaks and repair if necessary.
  26.  

4.5L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Drain the engine oil.
  8.  
  9. Remove or disconnect the following:

    Both battery cables
     
    Engine assembly from the vehicle and place it on a workstand
     
    Drive belt and idler pulley
     
    Thermostat housing
     
    Oil pan and strainer
     
    Upper and lower intake manifolds
     
    Fuel rail and injector assembly
     
    Ignition coils
     
    Spark plugs
     
    Valve cover
     
    Timing chain
     
    Camshafts
     

  10.  
  11. Loosen the cylinder head bolts gradually in reverse of the tightening sequence, then remove the cylinder head.
  12.  

To install:

  1. Be sure all mating surfaces are clean before installation.
  2.  
  3. Check the cylinder head surface for warpage using a feeler gauge and a suitable straightedge. If the cylinder head is warped more than 0.004 in. (0.1mm), it must be resurfaced or replaced. The total amount machined from the head or head and block combined, cannot total more than 0.008 in. (0.2mm).
  4.  
  5. If the cylinder head bolts are to be reused, measure the outside diameter of the bolt threads for distortion. If the dimension between d1 and d2 exceeds 0.0071 inch (0.18 mm), replace the bolts.
  6.  
  7. Place new gaskets on the cylinder block.
  8.  
  9. Apply clean engine oil to the cylinder head bolt threads.
  10.  
  11. Install the cylinder head and tighten the bolts in sequence to 72 ft. lbs. (98 Nm).
  12.  
  13. Loosen all bolts in sequence to zero.
  14.  
  15. Tighten all bolts in sequence again to 33 ft. lbs. (44 Nm), then tighten them an additional 60 degrees, then an additional 60 degrees.
  16.  
  17. Install or connect the following:

    Camshafts
     
    Timing chain
     
    Valve cover
     
    Spark plugs
     
    Ignition coils
     
    Fuel rail and injector assembly
     
    Upper and lower intake manifolds
     
    Oil pan and strainer
     
    Thermostat housing
     
    Drive belt and idler pulley
     
    Engine assembly
     
    Both battery cables
     

  18.  
  19. Fill and bleed the cooling system.
  20.  
  21. Fill the engine with clean oil.
  22.  
  23. Start the vehicle, check for leaks and repair if necessary.
  24.  


    Click image to see an enlarged view

    Fig. Checking the cylinder bolt threads for distortion-4.5L engine



    Click image to see an enlarged view

    Fig. Cylinder head bolt tightening sequence-4.5L engine


  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Drain the cooling system.
  6.  
  7. Drain the engine oil.
  8.  
  9. Remove or disconnect the following:

    Both battery cables
     
    Engine assembly from the vehicle and place it on a work stand
     
    Drive belt and idler pulley
     
    Thermostat housing
     
    Oil pan and strainer
     
    Upper and lower intake manifolds
     
    Fuel rail and injector assembly
     
    Ignition coils
     
    Spark plugs
     
    Valve cover
     
    Timing chain
     
    Camshafts
     

  10.  
  11. Loosen the cylinder head bolts gradually in reverse of the tightening sequence, then remove the cylinder head.
  12.  

To install:

  1. Be sure all mating surfaces are clean before installation.
  2.  
  3. Check the cylinder head surface for warpage using a feeler gauge and a suitable straightedge. If the cylinder head is warped more than 0.004 in. (0.1mm), it must be resurfaced or replaced. The total amount machined from the head or head and block combined, cannot total more than 0.008 in. (0.2mm).
  4.  
  5. If the cylinder head bolts are to be reused, measure the outside diameter of the bolt threads for distortion. If the dimension between d1 and d2 exceeds 0.0071 inch (0.18 mm), replace the bolts.

    Click image to see an enlarged view

    Fig. Checking the cylinder bolt threads for distortion-4.5L engine



    Click image to see an enlarged view

    Fig. Cylinder head bolt tightening sequence-4.5L engine

  6.  
  7. Place new gaskets on the cylinder block.
  8.  
  9. Apply clean engine oil to the cylinder head bolt threads.
  10.  
  11. Install the cylinder head and tighten the bolts in sequence (Refer to Torque Specifications Chart in beginning of chapter for torque values and procedures)
  12.  
  13. Install or connect the following:

    Camshafts
     
    Timing chain
     
    Valve cover
     
    Spark plugs
     
    Ignition coils
     
    Fuel rail and injector assembly
     
    Upper and lower intake manifolds
     
    Oil pan and strainer
     
    Thermostat housing
     
    Drive belt and idler pulley
     
    Engine assembly
     
    Both battery cables
     

  14.  
  15. Fill and bleed the cooling system.
  16.  
  17. Fill the engine with clean oil.
  18.  
  19. Start the vehicle, check for leaks and repair if necessary.
  20.  

 
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