Nissan Frontier, Xterra 1998-05

Cylinder Head

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Removal & Installation



2.5L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Disconnect the negative battery cable. Drain the cooling system. Drain the engine oil.
  6.  
  7. Remove the intake manifold and fuel tube assembly.
  8.  
  9. Remove the fuel injector and fuel tube assembly.
  10.  
  11. Remove the exhaust manifold and the three way catalyst.
  12.  
  13. Remove the water outlet. Remove the heater outlet.
  14.  
  15. Remove the front cover and the timing chain.
  16.  
  17. Remove the camshafts.
  18.  
  19. Remove the cylinder head retaining bolts. Be sure to remove the bolts by reversing the order of the tightening torque sequence.
  20.  
  21. Remove the cylinder head from the engine. Discard the gasket.
  22.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  
  3. Be sure to inspect the cylinder head bolts. Replace as required.
    NOTE
    Head bolts are tightened by plastic zone tightening method. Whenever the size difference between -d1- and -d2- exceeds the limit, replace the bolt. -d1---d2- limit is 0.0091. If reduction of the outer diameter appears in a position other than -d2-, use it the -d2- point.



    Click image to see an enlarged view

    Fig. Cylinder head bolt measurement-2.5L engine



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence-2.5L engine

  4.  
  5. Install the new cylinder head gasket. Torque the cylinder head bolts to specification and in the proper sequence.
  6.  
  7. Be sure to fill the cooling system with the proper grade and type engine coolant.
  8.  
  9. Be sure to fill the engine with the proper grade and type motor oil.
  10.  
  11. Start the engine and check for leaks.
  12.  

3.3L Engines


Click image to see an enlarged view

Fig. Exploded view of the cylinder head assembly-3.3L engine

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:

    Negative battery cable
     
    Accessory drive belts
     
    Front cover
     
    Timing belt. Refer to the Timing Belt unit repair section.
     
    Upper intake manifold
     
    Lower intake manifold
     
    Camshaft sprockets
     
    Rear timing cover
     
    Distributor
     
    Exhaust front pipes
     
    A/C compressor
     
    Alternator
     
    Power steering pump
     
    Accessory brackets
     
    Valve covers. Loosen the bolts in several passes and in sequence.
     
    Cylinder heads with the exhaust manifolds attached. Loosen the bolts in several passes and in sequence.
     

  8.  


NOTE
The cylinder head bolts vary in length. Note the bolt locations for assembly.

To install:



Click image to see an enlarged view

Fig. Cylinder head torque sequence-3.3L engine

  1. Install the cylinder heads and the lower intake manifold at the same time. Tighten the bolts in sequence as follows:
    1. Step 1: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    2.  
    3. Step 2: Tighten the cylinder head bolts to 43 ft. lbs. (59 Nm)
    4.  
    5. Step 3: Loosen all cylinder head bolts completely
    6.  
    7. Step 4: Tighten the cylinder head bolts to 84 inch lbs. (10 Nm)
    8.  
    9. Step 5: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    10.  
    11. Step 6: Tighten the intake manifold fasteners to 13 ft. lbs. (18 Nm)
    12.  
    13. Step 7: Tighten the intake manifold fasteners to 12-14 ft. lbs. (16-20 Nm)
    14.  
    15. Step 8: Loosen all intake fasteners completely
    16.  
    17. Step 9: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    18.  
    19. Step 10: Tighten the cylinder head bolts 60-65 degreesOR
    20.  
    21. Step 11: Tighten the cylinder head sub-bolts to 80-105 inch lbs. (9-12 Nm)
    22.  
    23. Step 12: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    24.  
    25. Step 13: Tighten the intake manifold fasteners to 78 inch lbs. (9 Nm)
    26.  
    27. Step 14: Tighten the intake manifold fasteners to 70-84 inch lbs. (6-7 Nm)
    28.  

  2.  
  3. Install or connect the following:

    Valve covers
     
    Accessory brackets
     
    Power steering pump
     
    Alternator
     
    A/C compressor
     
    Exhaust front pipes
     
    Distributor
     
    Rear timing cover
     
    Camshaft sprockets
     
    Upper intake manifold
     
    Timing belt
     
    Front cover
     
    Accessory drive belts
     
    Negative battery cable
     

  4.  
  5. Fill the cooling system.
  6.  
  7. Start the engine and check for leaks.
  8.  



Click image to see an enlarged view

Fig. Exploded view of the cylinder head assembly-3.3L engine

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:
    NOTE
    The cylinder head bolts vary in length. Note the bolt locations for assembly.



    Negative battery cable
     
    Accessory drive belts
     
    Front cover
     
    Timing belt. Refer to the Timing Belt unit repair section.
     
    Upper intake manifold
     
    Lower intake manifold
     
    Camshaft sprockets
     
    Rear timing cover
     
    Distributor
     
    Exhaust front pipes
     
    A/C compressor
     
    Alternator
     
    Power steering pump
     
    Accessory brackets
     
    Valve covers. Loosen the bolts in several passes and in sequence.
     
    Cylinder heads with the exhaust manifolds attached. Loosen the bolts in several passes and in sequence.
     

  8.  

To install:

Click image to see an enlarged view

Fig. Cylinder head torque sequence-3.3L engine

  1. Install the cylinder heads and the lower intake manifold at the same time. Tighten the bolts in sequence as follows:
    1. Step 1: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    2.  
    3. Step 2: Tighten the cylinder head bolts to 43 ft. lbs. (59 Nm)
    4.  
    5. Step 3: Loosen all cylinder head bolts completely
    6.  
    7. Step 4: Tighten the cylinder head bolts to 84 inch lbs. (10 Nm)
    8.  
    9. Step 5: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    10.  
    11. Step 6: Tighten the intake manifold fasteners to 13 ft. lbs. (18 Nm)
    12.  
    13. Step 7: Tighten the intake manifold fasteners to 12-14 ft. lbs. (16-20 Nm)
    14.  
    15. Step 8: Loosen all intake fasteners completely
    16.  
    17. Step 9: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    18.  
    19. Step 10: Tighten the cylinder head bolts 60-65 degrees OR tighten to 40-47 ft. lbs. (54-64 Nm)
    20.  
    21. Step 11: Tighten the cylinder head sub-bolts to 80-105 inch lbs. (9-12 Nm)
    22.  
    23. Step 12: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    24.  
    25. Step 13: Tighten the intake manifold fasteners to 78 inch lbs. (9 Nm)
    26.  
    27. Step 14: Tighten the intake manifold fasteners to 70-84 inch lbs. (6-7 Nm)
    28.  

  2.  
  3. Install or connect the following:

    Valve covers
     
    Accessory brackets
     
    Power steering pump
     
    Alternator
     
    A/C compressor
     
    Exhaust front pipes
     
    Distributor
     
    Rear timing cover
     
    Camshaft sprockets
     
    Upper intake manifold
     
    Timing belt
     
    Front cover
     
    Accessory drive belts
     
    Negative battery cable
     

  4.  
  5. Fill the cooling system.
  6.  
  7. Start the engine and check for leaks.
  8.  



Click image to see an enlarged view

Fig. Exploded view of the cylinder head assembly-3.3L engine

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:
    NOTE
    The cylinder head bolts vary in length. Note the bolt locations for assembly.



    Negative battery cable
     
    Accessory drive belts
     
    Front cover
     
    Timing belt. Refer to the Timing Belt unit repair section.
     
    Upper intake manifold
     
    Lower intake manifold
     
    Camshaft sprockets
     
    Rear timing cover
     
    Distributor
     
    Exhaust front pipes
     
    A/C compressor
     
    Alternator
     
    Power steering pump
     
    Accessory brackets
     
    Valve covers. Loosen the bolts in several passes and in sequence.
     
    Cylinder heads with the exhaust manifolds attached. Loosen the bolts in several passes and in sequence.
     

  8.  

To install:

Click image to see an enlarged view

Fig. Cylinder head torque sequence-3.3L engine

  1. Install the cylinder heads and the lower intake manifold at the same time. Tighten the bolts in sequence as follows:
    1. Step 1: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    2.  
    3. Step 2: Tighten the cylinder head bolts to 43 ft. lbs. (59 Nm)
    4.  
    5. Step 3: Loosen all cylinder head bolts completely
    6.  
    7. Step 4: Tighten the cylinder head bolts to 84 inch lbs. (10 Nm)
    8.  
    9. Step 5: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    10.  
    11. Step 6: Tighten the intake manifold fasteners to 13 ft. lbs. (18 Nm)
    12.  
    13. Step 7: Tighten the intake manifold fasteners to 12-14 ft. lbs. (16-20 Nm)
    14.  
    15. Step 8: Loosen all intake fasteners completely
    16.  
    17. Step 9: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    18.  
    19. Step 10: Tighten the cylinder head bolts 60-65 degrees OR tighten to 40-47 ft. lbs. (54-64 Nm)
    20.  
    21. Step 11: Tighten the cylinder head sub-bolts to 80-105 inch lbs. (9-12 Nm)
    22.  
    23. Step 12: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    24.  
    25. Step 13: Tighten the intake manifold fasteners to 78 inch lbs. (9 Nm)
    26.  
    27. Step 14: Tighten the intake manifold fasteners to 70-84 inch lbs. (6-7 Nm)
    28.  

  2.  
  3. Install or connect the following:

    Valve covers
     
    Accessory brackets
     
    Power steering pump
     
    Alternator
     
    A/C compressor
     
    Exhaust front pipes
     
    Distributor
     
    Rear timing cover
     
    Camshaft sprockets
     
    Upper intake manifold
     
    Timing belt
     
    Front cover
     
    Accessory drive belts
     
    Negative battery cable
     

  4.  
  5. Fill the cooling system.
  6.  
  7. Start the engine and check for leaks.
  8.  



Click image to see an enlarged view

Fig. Exploded view of the cylinder head assembly-3.3L engine

  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:
    NOTE
    The cylinder head bolts vary in length. Note the bolt locations for assembly.



    Negative battery cable
     
    Accessory drive belts
     
    Front cover
     
    Timing belt. Refer to the Timing Belt unit repair section.
     
    Upper intake manifold
     
    Lower intake manifold
     
    Camshaft sprockets
     
    Rear timing cover
     
    Distributor
     
    Exhaust front pipes
     
    A/C compressor
     
    Alternator
     
    Power steering pump
     
    Accessory brackets
     
    Valve covers. Loosen the bolts in several passes and in sequence.
     
    Cylinder heads with the exhaust manifolds attached. Loosen the bolts in several passes and in sequence.
     

  8.  

To install:

Click image to see an enlarged view

Fig. Cylinder head torque sequence-3.3L engine

  1. Install the cylinder heads and the lower intake manifold at the same time. Tighten the bolts in sequence as follows:
    1. Step 1: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    2.  
    3. Step 2: Tighten the cylinder head bolts to 43 ft. lbs. (59 Nm)
    4.  
    5. Step 3: Loosen all cylinder head bolts completely
    6.  
    7. Step 4: Tighten the cylinder head bolts to 84 inch lbs. (10 Nm)
    8.  
    9. Step 5: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    10.  
    11. Step 6: Tighten the intake manifold fasteners to 13 ft. lbs. (18 Nm)
    12.  
    13. Step 7: Tighten the intake manifold fasteners to 12-14 ft. lbs. (16-20 Nm)
    14.  
    15. Step 8: Loosen all intake fasteners completely
    16.  
    17. Step 9: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    18.  
    19. Step 10: Tighten the cylinder head bolts 60-65 degrees OR tighten to 40-47 ft. lbs. (54-64 Nm)
    20.  
    21. Step 11: Tighten the cylinder head sub-bolts to 80-105 inch lbs. (9-12 Nm)
    22.  
    23. Step 12: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    24.  
    25. Step 13: Tighten the intake manifold fasteners to 78 inch lbs. (9 Nm)
    26.  
    27. Step 14: Tighten the intake manifold fasteners to 70-84 inch lbs. (6-7 Nm)
    28.  

  2.  
  3. Install or connect the following:

    Valve covers
     
    Accessory brackets
     
    Power steering pump
     
    Alternator
     
    A/C compressor
     
    Exhaust front pipes
     
    Distributor
     
    Rear timing cover
     
    Camshaft sprockets
     
    Upper intake manifold
     
    Timing belt
     
    Front cover
     
    Accessory drive belts
     
    Negative battery cable
     

  4.  
  5. Fill the cooling system.
  6.  
  7. Start the engine and check for leaks.
  8.  

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Relieve the fuel system pressure.
  6.  
  7. Remove or disconnect the following:
    NOTE
    The cylinder head bolts vary in length. Note the bolt locations for assembly.



    Negative battery cable
     
    Accessory drive belts
     
    Front cover
     
    Timing belt. Refer to the Timing Belt unit repair section.
     
    Upper intake manifold
     
    Lower intake manifold
     
    Camshaft sprockets
     
    Rear timing cover
     
    Distributor
     
    Exhaust front pipes
     
    A/C compressor
     
    Alternator
     
    Power steering pump
     
    Accessory brackets
     
    Valve covers. Loosen the bolts in several passes and in sequence.
     
    Cylinder heads with the exhaust manifolds attached. Loosen the bolts in several passes and in sequence.
     

  8.  

To install:

Click image to see an enlarged view

Fig. Cylinder head bolt torque sequence-3.3L engine

  1. Install the cylinder heads and the lower intake manifold at the same time. Tighten the bolts in sequence as follows:
    1. Step 1: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    2.  
    3. Step 2: Tighten the cylinder head bolts to 43 ft. lbs. (59 Nm)
    4.  
    5. Step 3: Loosen all cylinder head bolts completely
    6.  
    7. Step 4: Tighten the cylinder head bolts to 84 inch lbs. (10 Nm)
    8.  
    9. Step 5: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    10.  
    11. Step 6: Tighten the intake manifold fasteners to 13 ft. lbs. (18 Nm)
    12.  
    13. Step 7: Tighten the intake manifold fasteners to 12-14 ft. lbs. (16-20 Nm)
    14.  
    15. Step 8: Loosen all intake fasteners completely
    16.  
    17. Step 9: Tighten the cylinder head bolts to 22 ft. lbs. (29 Nm)
    18.  
    19. Step 10: Tighten the cylinder head bolts 60-65 degrees OR tighten to 40-47 ft. lbs. (54-64 Nm)
    20.  
    21. Step 11: Tighten the cylinder head sub-bolts to 80-105 inch lbs. (9-12 Nm)
    22.  
    23. Step 12: Tighten the intake manifold fasteners to 35 inch lbs. (4 Nm)
    24.  
    25. Step 13: Tighten the intake manifold fasteners to 78 inch lbs. (9 Nm)
    26.  
    27. Step 14: Tighten the intake manifold fasteners to 70-84 inch lbs. (6-7 Nm)
    28.  

  2.  
  3. Install or connect the following:

    Valve covers
     
    Accessory brackets
     
    Power steering pump
     
    Alternator
     
    A/C compressor
     
    Exhaust front pipes
     
    Distributor
     
    Rear timing cover
     
    Camshaft sprockets
     
    Upper intake manifold
     
    Timing belt
     
    Front cover
     
    Accessory drive belts
     
    Negative battery cable
     

  4.  
  5. Fill the cooling system.
  6.  
  7. Start the engine and check for leaks.
  8.  

4.0L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Disconnect the negative battery cable. Drain the cooling system.
  6.  
  7. Remove the camshaft.
  8.  
  9. Remove the intake manifold.
  10.  
  11. Remove the exhaust manifold.
  12.  
  13. Remove the water inlet and thermostat assembly.
  14.  
  15. Remove the water outlet, water pipe and heater pipe.
  16.  
  17. Remove the cylinder head retaining bolts. Be sure to remove the bolts by reversing the order of the tightening torque sequence.
  18.  
  19. Remove the cylinder head from the engine. Discard the gasket.
  20.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  
  3. Be sure to inspect the cylinder head bolts. Replace as required.
    NOTE
    Head bolts are tightened by plastic zone tightening method. Whenever the size difference between -d1- and -d2- exceeds the limit, replace the bolt. -d1---d2- limit is 0.0043. If reduction of the outer diameter appears in a position other than -d2-, use it the -d2- point.



    Click image to see an enlarged view

    Fig. Cylinder head bolt measurement-4.0L engine



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence-4.0L engine

  4.  
  5. Install the new cylinder head gasket. Turn the crankshaft until the number one piston is at TDC.
    NOTE
    The crankshaft key should line up with the right bank center line, see illustration.



    Click image to see an enlarged view

    Fig. Cylinder head and crankshaft key alignment-4.0L engine



    Click image to see an enlarged view

    Fig. Cylinder head to cylinder block installation measurement-4.0L engine

  6.  
  7. Torque the cylinder head bolts to specification and in the proper sequence.
  8.  
  9. Measure the distance between the front end faces of the cylinder block and the cylinder head on both the left and right banks. If the measured value is not within specification reinstall the cylinder head. Specification is 0.555-0.587 inch.
  10.  
  11. Be sure to fill the cooling system with the proper grade and type engine coolant.
  12.  
  13. Start the engine and check for leaks.
  14.  

 
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