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    1995 Nissan/Datsun Altima 2.4L SFI DOHC 4cyl

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    1720 S RIDGEWOOD A
    (386) 427-1210

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    Isuzu Cars and Trucks 1981-1991

    Cylinder Head

    Print

    REMOVAL AND INSTALLATION
    G180Z and G200Z Engine
    1. Disconnect the negative battery cable and drain the engine coolant. Remove the rocker cover.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Remove the EGR pipe clamp bolt at the rear of the cylinder head.
    2.  
    3. Raise and support the vehicle safely. Disconnect the exhaust pipe at the exhaust manifold.
    4.  
    5. Lower the vehicle.
    6.  
    7. Disconnect the heater hoses at the intake manifold and at the rear of the cylinder head. Remove the air conditioning compressor and/or power steering pump with hoses attached and support them aside.
    8.  
    9. Disconnect the accelerator linkage and fuel line at the carburetor. Disconnect and label the electrical connections, spark plug wires and vacuum lines at the cylinder head.
    10.  
    11. Rotate the engine until the No. 4 cylinder is in the firing position. Remove the distributor cap and mark the rotor to housing relationship. Remove distributor and the fuel pump.
    12.  
    13. Lock the timing chain adjuster by depressing and turning the automatic adjuster side pin 90and#x00B0; clockwise.
    14.  
    15. Remove the timing sprocket-to-camshaft bolt and remove the sprocket from the camshaft.
    16.  


    NOTE
    Keep the sprocket on the chain damper and chain.

    1. Disconnect the AIR hose and the check valve at the exhaust manifold.
    2.  
    3. Remove the cylinder head to timing cover bolts.
    4.  
    5. Starting with the outer bolts and working inward, remove the cylinder head bolts.
    6.  
    7. Remove the cylinder head, intake and exhaust manifold as a unit. Remove all accessories if the manifold has to be serviced.
    8.  



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence G180Z and G200Z engines



    Click image to see an enlarged view

    Fig. Locking the timing chain adjuster G180Z engine



    Click image to see an enlarged view

    Fig. Keep the timing sprocket attached to the chain while aligning or removing



    Click image to see an enlarged view

    Fig. Locking the timing chain adjuster G200Z engine



    Click image to see an enlarged view

    Fig. Push in on the automatic adjuster shoe 1 and lock it in the retracted position by releasing the lever 2 G200Z engine

    To install:

    1. Clean the gasket mating surfaces with scraper and solvent. Check the cylinder head and block for warpage using a straight edge and feeler gauge. Refer to "Cylinder Head Inspection" section in this Section.
    2.  
    3. Use a new gasket and install the cylinder head on the engine.
    4.  
    5. Torque the bolts to specifications. Refer to the "Torque" specification chart in the beginning of this Section.
    6.  
    7. Install the timing chain by performing the following procedures:
    8.  
      1. Install the timing sprocket and pinion gear with the groove side toward the front cover. Align the key grooves with the key on the crankshaft, then drive into position.
      2.  
      3. Confirm that the No. 1 piston is at TDC. If not, turn the crankshaft so the key is turned toward the cylinder head side (No. 1 and No. 4 pistons at top dead center).
      4.  
      5. Install the timing chain by aligning the mark plate on the chain with the mark on the crankshaft timing sprocket. The side of the chain with the mark plate is on the front side and the side of the chain with the most links between the mark plates is on the chain guide side.
      6.  
      7. Install the camshaft timing sprocket so the mark side of the sprocket faces forward and so the triangular mark aligns with the chain mark plate.
      8.  



    NOTE
    Keep the timing chain engaged with the camshaft timing sprocket until the sprocket is installed on the camshaft.

    1. Install the front cover assembly, using a new gasket and sealer.
    2.  
    3. Connect the AIR hose and the check valve at the exhaust manifold.
    4.  
    5. Connect the accelerator linkage and fuel line to the carburetor. Connect the electrical connections, the spark plug wires and the vacuum lines.
    6.  
    7. Connect the heater hoses to the intake manifold and the rear of the cylinder head. Install the air conditioner compressor and/or power steering pump.
    8.  
    9. Connect the exhaust pipe to the exhaust manifold.
    10.  
    11. Install the EGR pipe clamp bolt to the rear of the cylinder head.
    12.  
    13. Install the rocker arm cover and connect the negative battery cable.
    14.  
    15. Refill the engine with coolant. Start the engine and check for leaks.
    16.  

    4XC1-U and 4XC1-T Engines
    1. Disconnect the negative battery cable and drain the cooling system into a suitable drain pan.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Remove the air cleaner assembly and disconnect the flex hose along with the oxygen sensor at the exhaust manifold.
    2.  
    3. Disconnect the exhaust pipe bracket at the block and the exhaust pipe at the manifold. On turbocharged model remove exhaust pipe at wastegate manifold, and remove vacuum line for turbocharger control.
    4.  
    5. Disconnect the spark plug wires and remove the thermostat housing.
    6.  
    7. Rotate the engine until the engine is at TDC on the compression stroke of the No. 1 cylinder. Remove distributor cap and mark the distributor rotor to housing position and housing to cylinder head. Remove the distributor hold down bolt and remove the distributor.
    8.  
    9. Remove the vacuum advance hoses and the ground cable at the cylinder head.
    10.  
    11. Disconnect the fuel lines at the fuel pump and at the carburetor, remove the secondary hoses and throttle cable on non-turbocharged model.
    12.  
    13. Remove engine wiring harness assembly from fuel injectors and fuel line from fuel injector pipe on turbocharged model.
    14.  
    15. Disconnect the vacuum switching valve electrical connector and the heater hoses.
    16.  
    17. Remove the alternator, power steering pump and air conditioning adjusting bolts, brackets and drive belts. Remove and tag all necessary electrical and vacuum lines.
    18.  
    19. Support the engine using a suitable vertical hoist. Remove the right hand motor mount and the bracket at the front cover.
    20.  
    21. Remove the crankshaft bolt and remove the boss and the crank pulley.
    22.  
    23. Remove the timing cover and be sure the mark on the cam pulley is aligned with the upper surface of the cylinder head. Also the dowel pin on the camshaft should be positioned at the top.
    24.  
    25. Disconnect the PCV hoses and remove the valve cover. If the cover sticks to the head, carefully strike the valve cover with a soft mallet.
    26.  
    27. Insert a hex wrench into the tension pulley hexagonal hole. Loosen the timing belt tension by rotating the tension pulley clockwise and remove the timing belt.
    28.  
    29. Remove the fuel pump (non-turbocharged model) and disconnect the intake manifold coolant hoses.
    30.  
    31. Remove the cylinder head bolts, remove the bolts from both ends at the same time, working toward the middle and remove the cylinder head.
    32.  



    Click image to see an enlarged view

    Fig. Rocker arm shaft torque sequence 4XC1-U and 4XC1-T, to 16 ft. lbs. (22 Nm)



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence 4XC1-U and 4XC1-T engines

    To install:

    1. To install, use new seals and gaskets, apply oil to the head bolt threads and torque the head bolts.
    2.  


    NOTE
    When torquing the cylinder head bolts, work from the middle toward both ends at the same time. The torque should be 29 ft. lbs. on the first pass and 58 ft. lbs. on the second pass.

    1. After torquing the head bolts, adjust the valve clearance.
    2.  
    3. Install the fuel pump (non-turbocharged model) and connect the intake manifold coolant hoses.
    4.  
    5. Install the timing belt. Insert a hex wrench into the tension pulley hexagonal hole. tighten the timing belt tension by rotating the tension pulley counterclockwise.
    6.  
    7. Connect the PCV hoses and install the valve cover with new gasket.
    8.  
    9. Install the timing cover and be sure the mark on the cam pulley is aligned with the upper surface of the cylinder head. Also the dowel pin on the camshaft should be positioned at the top.
    10.  
    11. Install the crankshaft pulley and bolt.
    12.  
    13. Install the right hand motor mount and the bracket at the front cover.
    14.  
    15. Install the alternator, power steering pump and air conditioning adjusting bolts, brackets and drive belts. Connect all necessary electrical and vacuum lines.
    16.  
    17. Connect the vacuum switching valve electrical connector and the heater hoses.
    18.  
    19. Install engine wiring harness assembly from fuel injectors and fuel line from fuel injector pipe on turbocharged model.
    20.  
    21. Connect the fuel lines at the fuel pump and at the carburetor, install the secondary hoses and throttle cable on non-turbocharged model.
    22.  
    23. Install the vacuum advance hoses and the ground cable at the cylinder head.
    24.  
    25. Install the distributor hold down bolt and distributor to the marked position.
    26.  
    27. Connect the spark plug wires and install the thermostat housing.
    28.  
    29. Connect the exhaust pipe bracket at the block and the exhaust pipe at the manifold. On turbocharged model install exhaust pipe at wastegate manifold, and connect vacuum line for turbocharger control.
    30.  
    31. Install the air cleaner assembly and connect the flex hose along with the oxygen sensor at the exhaust manifold.
    32.  
    33. Connect the negative battery cable and refill the cooling system.
    34.  

    4ZD1, 4ZC1-T, 4XE1 (SOHC) Engines
    1. Disconnect negative battery cable and drain cooling system.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Rotate the engine until the engine is at TDC on the compression stroke of the No. 1 cylinder, make sure timing mark is on the scale. Remove distributor cap and mark the distributor rotor to housing position and housing to cylinder head. Remove the distributor hold down bolt and remove the distributor.
    2.  
    3. Disconnect radiator inlet and outlet hoses and remove the radiator.
    4.  
    5. Remove the alternator and the air conditioner drive belts. Remove engine fan.
    6.  
    7. Remove the crankshaft pulley center bolt and remove the pulley and hub assembly.
    8.  
    9. Remove the air pump belt and move the air pump out of the way. Remove the air conditioning compressor and lay it to one side (if equipped with air conditioning). Remove the compressor mounting bracket.
    10.  
    11. Remove the water pump pulley. Remove the top section of the front cover and the water pump.
    12.  
    13. Remove the lower section of the front cover.
    14.  
    15. Remove the tension spring. Loosen the top bolt of the tension pulley and draw the tension pulley fully to the water pump side.
    16.  
    17. Remove the timing belt.
    18.  
    19. Remove cam cover.
    20.  
    21. Sequentially loosen and remove the rocker arm shaft tightening nuts from the outermost one and remove the rocker arm shaft with the bracket as an assembly.
    22.  
    23. Raise vehicle and disconnect the exhaust pipe at the exhaust manifold. On turbocharged model disconnect exhaust pipe from wastegate manifold and remove control cable for turbocharger.
    24.  
    25. Lower vehicle disconnect all lines, hoses, electrical connections and spark plug wires.
    26.  


    NOTE
    Tag all wires and hoses before disconnecting them from the engine.

    1. Disconnect the accelerator linkage, on turbocharged model remove engine wiring harness assembly from fuel injectors and fuel line from fuel injector pipe.
    2.  
    3. Remove the cylinder head bolts using an extension bar with socket. Remove bolts in progressive sequence, beginning with the outer bolts.
    4.  


    NOTE
    Use light oil to free frozen bolts.

    1. With the aid of an assistant, remove the cylinder head, intake and exhaust manifolds as an assembly.
    2.  



    Click image to see an enlarged view

    Fig. Rocker arm shaft torque sequence. Torque nuts 1-8 to 16 ft. lbs. (22 Nm), and nuts 9-10 to 60 inch lbs. (7 Nm) 4ZD1 and 4ZC1-T engines



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence 4ZD1 and 4ZC1-T engines



    Click image to see an enlarged view

    Fig. Cylinder head torque sequence 4XE1 SOHC engine



    Click image to see an enlarged view

    Fig. Camshaft pulley alignment marks 4XE1 SOHC engine

    To install:

    1. Clean all gasket material from the cylinder head and block surfaces. Check for nicks or heavy scratches on the mating surfaces.
    2.  
    3. Cylinder bolt threads in the block and threads on the bolts must be cleaned. Dirt will affect head torque.
    4.  
    5. Match up the old gasket with the new gasket to make sure it is an exact fit.
    6.  
    7. Install the gasket and cylinder head with the help of an assistant. Torque in sequence and 2 steps first step 57 ft. lbs. (76 Nm) and second step 72 ft. lbs. (96 Nm).
    8.  
    9. Connect the accelerator linkage, on turbocharged model install engine wiring harness assembly to fuel injectors and fuel line to fuel injector pipe.
    10.  
    11. Connect all lines, hoses, electrical connections and spark plug wires.
    12.  
    13. Raise vehicle and connect the exhaust pipe at the exhaust manifold. On turbocharged model connect exhaust pipe to wastegate manifold and install control cable for turbocharger.
    14.  
    15. Sequentially install and torque the rocker arm shaft tightening nuts from the outermost one and install the rocker arm shaft with the bracket as an assembly. Refer to the appropriate illustration.
    16.  
    17. Install the rocker arm cover.
    18.  
    19. Install the timing belt.
    20.  
    21. Install the tension spring. Tighten the top bolt of the tension pulley.
    22.  
    23. Install the lower section of the front cover.
    24.  
    25. Install the water pump pulley. Install the top section of the front cover and the water pump.
    26.  
    27. Install the air pump and belt. Install the air conditioning compressor bracket and compressor.
    28.  
    29. Install the crankshaft pulley and center bolt.
    30.  
    31. Install the alternator and the air conditioner drive belts. Install engine fan.
    32.  
    33. Connect radiator inlet and outlet hoses and after installing the radiator.
    34.  
    35. Install the distributor, hold down bolt and cap.
    36.  
    37. Connect negative battery cable, refill the cooling system and check for leaks.
    38.  

    4XE1 DOHC Engine

    NOTE
    The following procedure is the long version of cylinder head removal for I-Mark, Stylus and Impulse equipped with the 4XE1 DOHC engine. The instruction below may be altered as seen fit by the technician using this procedure. It may also be necessary to remove the engine from the vehicle in order to remove the cylinder head.

    1. Disconnect negative battery cable and drain cooling system. Remove the air cleaner duct hose from the common chamber.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Rotate the engine until the engine is at TDC on the compression stroke of the No. 1 cylinder, make sure timing mark is on the scale. Remove distributor cap and mark the distributor rotor to housing position and housing to cylinder head. Remove the distributor hold down bolt and remove the distributor.
    2.  
    3. Disconnect radiator inlet and outlet hoses along with transmission oil cooler lines, if so equipped and remove the radiator.
    4.  
    5. Remove the power steering pump drive belt, for vehicles with air conditioners, remove the power steering pump and compressor drive belt. Loosen the 2 power steering pump adjust plates bolts.
    6.  
    7. Remove the alternator drive belt from the crank pulley side. Disconnect the clip securing the high pressure air conditioning line to the strut tower.
    8.  
    9. Disconnect and tag the following vacuum lines and wiring harness:
    10.  
      1. Fast idle vacuum hose from the air duct hose.
      2.  
      3. The MAP sensor vacuum hose from the common chamber.
      4.  
      5. Disconnect the TPC valve vacuum hose from the common chamber.
      6.  
      7. Disconnect the canister vacuum hose from the common chamber.
      8.  
      9. Electronic control gas injection harness, disconnect the 2 ECM ground connectors from the bracket located on top of the common chamber. Disconnect the 2 green and black multi-pin connectors on the top of the common chamber.
      10.  
      11. Remove the MAT sensor connector.
      12.  

    11. Disconnect the accelerator cable from the throttle body and at the common chamber. Disconnect the PCV valve hose from the valve cover.
    12.  
    13. Disconnect the master vacuum hose from the master vacuum tube at the common chamber side.
    14.  
    15. Disconnect the induction valve vacuum hose from the common chamber. Disconnect the EGR valve and the throttle valve.
    16.  
    17. Remove the fuel hose clips from the common chamber. Remove the common (intake) chamber retaining bolts and remove the chamber. Disconnect the fuel injection harness from the fuel injector.
    18.  
    19. Remove the fuel rail assembly. Disconnect the induction control vacuum switching valve harness connection. Disconnect the idle air control valve connector and vacuum hose. Remove the air induction control valve assembly.
    20.  
    21. Disconnect the center (valve) cover and disconnect (and tag) the high tension cables from the spark plugs and clips.
    22.  
    23. Remove the pulse air bracket with pipe. Remove the heat protector and the EGR pipe.
    24.  
    25. Disconnect the exhaust pipe from the exhaust manifold and remove the exhaust hanger. Remove the exhaust manifold bolts along with the manifold.
    26.  
    27. Remove the coolant bypass line and the thermostat housing.
    28.  
    29. Remove the engine mounting bridge.
    30.  
    31. Remove the upper timing belt cover.
    32.  
    33. Using a suitable engine hoist, slightly raise and support the engine safely.
    34.  
    35. Remove the passenger side engine mount from the engine. Disconnect the torque rod at the firewall.
    36.  
    37. Remove the passenger side engine mounting bracket from the engine. Using special crank pulley tool J-37988 or equivalent, remove the crank pulley bolt.
    38.  
    39. Raise the passenger side of the engine, be sure that the front wheels remain on the ground while lifting the engine. Raise the engine too high will left the front wheels off the ground and may cause damage to the drive shaft universal joint.
    40.  
    41. Remove the timing belt lower cover. Remove the cranking pulley and extract up through the engine compartment. Refit the crank pulley bolt. Align the crank pulley timing gear to top dead center.
    42.  
    43. Loosen the tension pulley bolt a 1 / 2 turn counterclockwise. If the pulley bolt is loosened more than 1 / 2 a turn, the pulley will swing too far out of adjustment and may be difficult to readjust.
    44.  
    45. Mark the direction of rotation of the timing mark with a piece of chalk and remove the timing belt.
    46.  
    47. Loosen and remove the cylinder head bolts from the outermost one and remove the cylinder head from the engine.
    48.  



    Click image to see an enlarged view

    Fig. Cylinder head bolt loosening sequence 4XE1 DOHC engine



    Click image to see an enlarged view

    Fig. Camshaft bearing cap torque sequence 4XE1 DOHC engine



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence 4XE1 DOHC engine



    Click image to see an enlarged view

    Fig. Camshaft timing marks 4XE1 DOHC engine



    Click image to see an enlarged view

    Fig. Timing belt tension adjuster 4XE1 DOHC engine

    To install:

    1. Clean all gasket material from the cylinder head and block surfaces. Check for nicks or heavy scratches on the mating surfaces.
    2.  
    3. Cylinder bolt threads in the block and threads on the bolts must be cleaned. Dirt will affect head torque.
    4.  
    5. Torque in sequence and 2 steps first step 29 ft. lbs. (40 Nm) and second step 58 ft. lbs. (80 Nm).
    6.  
    7. Install the timing belt as outlined in the "Timing Belt" section in this Section.
    8.  
    9. Tighten the tension pulley bolt a 1 / 2 turn clockwise.
    10.  
    11. Install the timing belt lower cover. Install the cranking pulley. Refit the crank pulley bolt. Align the crank pulley timing gear to top dead center.
    12.  
    13. Lower passenger side of the engine.
    14.  
    15. Install the passenger side engine mounting bracket to the engine. Install the crank pulley bolt.
    16.  
    17. Install the passenger side engine mount to the engine. Connect the torque rod at the firewall.
    18.  
    19. Install the upper timing belt cover.
    20.  
    21. Install the engine mounting bridge.
    22.  
    23. Install the coolant bypass line and the thermostat housing.
    24.  
    25. Install the exhaust manifold bolts along with the manifold. Connect the exhaust pipe to the exhaust manifold and install the exhaust hanger.
    26.  
    27. Install the pulse air bracket with pipe. Install the heat protector and the EGR pipe.
    28.  
    29. Connect the high tension cables to the spark plugs and clips and install the center cover.
    30.  
    31. Connect the induction control vacuum switching valve harness connection. Install the fuel rail assembly. Connect the idle air control valve connector and vacuum hose. Install the air induction control valve assembly.
    32.  
    33. Install the common (intake) chamber and retaining bolts. Install the fuel hose clips to the common chamber. Connect the fuel injection harness to the fuel injector.
    34.  
    35. Connect the induction valve vacuum hose to the common chamber. Connect the EGR valve and the throttle valve.
    36.  
    37. Connect the master vacuum hose to the master vacuum tube at the common chamber side.
    38.  
    39. Connect the accelerator cable to the throttle body and at the common chamber. Connect the PCV valve hose to the valve cover.
    40.  
    41. Connect the following vacuum lines and wiring harness:
    42.  
      1. Install the MAT sensor connector.
      2.  
      3. Electronic control gas injection harness, connect the 2 ECM ground connectors to the bracket located on top of the common chamber. Connect the 2 green and black multi-pin connectors on the top of the common chamber.
      4.  
      5. Connect the canister vacuum hose to the common chamber.
      6.  
      7. Connect the TPC valve vacuum hose to the common chamber.
      8.  
      9. Connect MAP sensor vacuum hose to the common chamber.
      10.  
      11. Connect the fast idle vacuum hose to the air duct hose.
      12.  

    43. Install the alternator drive belt to the crank pulley side.
    44.  
    45. Install the power steering pump drive belt, for vehicles with air conditioners, install the power steering pump and compressor drive belt. Tighten the 2 power steering pump adjust plates bolts.
    46.  
    47. Install the radiator and connect radiator inlet and outlet hoses along with transmission oil cooler lines, if so equipped.
    48.  
    49. Install the distributor, hold down bolt and cap.
    50.  
    51. Connect negative battery cable and refill the cooling system. Install the air cleaner duct hose to the common chamber.
    52.  
    53. Start the engine and check for leaks.
    54.  

    4ZE1 Engine
    1. Relieve the fuel pressure. Disconnect the negative battery cable. Drain the cooling system.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Remove the drive belts from the power steering pump, the air pump, the air conditioning compressor (if equipped) and the cooling fan.
    2.  
    3. Rotate the engine to position the No. 1 cylinder on TDC.
    4.  
    5. Remove the distributor cap, high tension cables and the distributor.
    6.  
    7. Remove the exhaust manifold-to-exhaust pipe bolts.
    8.  
    9. Label and disconnect the electrical connectors and vacuum hoses which may be in the way.
    10.  
    11. Remove the coolant hoses, the radiator and the cooling fan assembly.
    12.  
    13. Remove the crankshaft pulley bolt and the pulley.
    14.  
    15. Remove the upper and lower timing belt covers, the tension spring and the timing belt.
    16.  
    17. Remove the camshaft pulley bolt, the pulley and the camshaft boss.
    18.  
    19. Remove the timing belt book plate and the cylinder head front plate.
    20.  
    21. Remove the rocker arm cover and gasket.
    22.  
    23. Remove the cylinder head-to-engine bolts, the cylinder head and gasket.
    24.  
    25. Clean the gasket mounting surfaces.
    26.  

    To install:



    Click image to see an enlarged view

    Fig. Rocker arm shaft torque sequence 4ZE1 engine



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence 4ZE1 engine

    1. Using a new gasket, install the cylinder head and torque the bolts, in sequence to 57 ft. lbs. (76 Nm) in the 1st step and to 65 and 1979 ft. lbs. (88 and 19108 Nm) in the final step.
    2.  
    3. Install the camshaft pulley.
    4.  
    5. Using a new gasket, install the rocker arm cover.
    6.  
    7. Align the camshaft pulley mark with the mark on the front plate. Make sure the keyway on the crankshaft if facing upward, aimed at the pointer on the engine block.
    8.  
    9. Install the timing belt in the following order: crankshaft pulley, the oil pump pulley, the camshaft and the tensioner.
    10.  
    11. Install the timing belt covers, using a new gasket.
    12.  
    13. Install the crankshaft pulley.
    14.  
    15. Install the cooling fan assembly, the radiator and the coolant hoses.
    16.  
    17. Connect the electrical connectors and vacuum hoses.
    18.  
    19. Install the exhaust manifold-to-exhaust pipe bolts.
    20.  
    21. Install the distributor, the distributor cap, and the high tension cables.
    22.  
    23. Install the drive belts to the power steering pump, the air pump, the air conditioning compressor (if equipped) and the cooling fan.
    24.  
    25. Connect the negative battery cable. Refill the cooling system.
    26.  
    27. Start the engine and check for leaks.
    28.  

    V6 Engine
    LEFT SIDE
    1. Relieve the fuel pressure. Disconnect the negative battery cable. Drain the cooling system.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Remove the intake manifold.
    2.  
    3. Raise and safely support the vehicle.
    4.  
    5. Disconnect the exhaust pipe from the exhaust manifold and remove the exhaust manifold-to-cylinder head bolts.
    6.  
    7. Remove the dipstick tube from the engine.
    8.  
    9. Lower the vehicle.
    10.  
    11. Loosen the rocker arm nuts, turn the rocker arms and remove the pushrods; keep the pushrods in the same order as removed.
    12.  
    13. Remove the cylinder head bolts in stages and in the reverse order of torquing.
    14.  
    15. Remove the cylinder head; do not pry on the head to loosen it.
    16.  
    17. Clean the gasket mounting surfaces.
    18.  



    Click image to see an enlarged view

    Fig. Cylinder head torque sequence V6 engine

    To install:

    1. Position a new cylinder head gasket over the dowel pins with the words This Side Up facing upwards. Carefully, book the cylinder head into place.
    2.  
    3. Install the pushrods; make sure the lower ends are in the lifter heads. Rotate the crankshaft until # 1 cylinder is at top dead center of the compression stroke. Adjust the intake valves for cylinders one, five and six, then adjust the exhaust valves for cylinders one, two and three. Loosen the rocker arm adjusting nut until you can spin the pushrod between your thumb and forefinger. Tighten the adjusting nut until the rocker arm contact with the pushrod stops your ability to spin the pushrod. Then tighten the adjusting nut an additional one and one half turns. Rotate the crankshaft until # 4 cylinder is at top dead center of the compression stroke. Adjust the intake valves for cylinders two, three and four, then adjust the exhaust valves for cylinders four, five and six. Loosen the rocker arm adjusting nut until you can spin the pushrod between your thumb and forefinger. Tighten the adjusting nut until the rocker arm contact with the pushrod stops your ability to spin the pushrod. Then tighten the adjusting nut an additional one and one half turns.
    4.  
    5. Install the intake manifold.
    6.  
    7. Install the dipstick tube to the engine.
    8.  
    9. Install the exhaust manifold-to-cylinder head bolts and the exhaust pipe-to-exhaust manifold nuts.
    10.  
    11. Refill the cooling system. Start the engine and check for leaks.
    12.  

    RIGHT SIDE
    1. Relieve the fuel pressure. Disconnect the negative battery cable. Drain the cooling system.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Remove the intake manifold.
    2.  
    3. If equipped, remove the cruise control servo bracket, the air management valve and hose.
    4.  
    5. Raise and safely support the vehicle.
    6.  
    7. Disconnect the exhaust pipe from the exhaust manifold and remove the exhaust manifold-to-cylinder head bolts.
    8.  
    9. Remove the exhaust pipe at crossover, the crossover and the heat shield, if equipped.
    10.  
    11. Lower the vehicle.
    12.  
    13. Label and disconnect the electrical wiring and vacuum hoses that may interfere with the removal of the right cylinder head.
    14.  
    15. Loosen the rocker arm nuts, turn the rocker arms and remove the pushrods; keep the pushrods in the same order as removed.
    16.  
    17. Remove the cylinder head bolts in stages and in the reverse order of torquing.
    18.  
    19. Remove the cylinder head; do not pry on the head to loosen it.
    20.  
    21. Clean the gasket mounting surfaces.
    22.  

    To install:



    Click image to see an enlarged view

    Fig. Cylinder head torque sequence V6 engine

    1. Position a new cylinder head gasket over the dowel pins with the words This Side Up facing upwards. Carefully, book the cylinder head into place.
    2.  
    3. Install the pushrods; make sure the lower ends are in the lifter heads. Rotate the crankshaft until # 1 cylinder is at top dead center of the compression stroke. Adjust the intake valves for cylinders one, five and six, then adjust the exhaust valves for cylinders one, two and three. Loosen the rocker arm adjusting nut until you can spin the pushrod between your thumb and forefinger. Tighten the adjusting nut until the rocker arm contact with the pushrod stops your ability to spin the pushrod. Then tighten the adjusting nut an additional one and one half turns. Rotate the crankshaft until # 4 cylinder is at top dead center of the compression stroke. Adjust the intake valves for cylinders two, three and four, then adjust the exhaust valves for cylinders four, five and six. Loosen the rocker arm adjusting nut until you can spin the pushrod between your thumb and forefinger. Tighten the adjusting nut until the rocker arm contact with the pushrod stops your ability to spin the pushrod. Then tighten the adjusting nut an additional one and one half turns.
    4.  
    5. Install the intake manifold.
    6.  
    7. Install the exhaust pipe at crossover, the crossover and the heat shield, if equipped.
    8.  
    9. Install the exhaust manifold-to-cylinder head bolts and the exhaust pipe-to-exhaust manifold nuts.
    10.  
    11. Connect the electrical wiring and vacuum hoses to the right cylinder head.
    12.  
    13. If equipped, install the cruise control servo bracket, the air management valve and hose.
    14.  
    15. Refill the cooling system. Start the engine and check for leaks.
    16.  

    C223 and C223-T Engine
    1. Relieve the fuel pressure. Disconnect the negative battery cable. Drain the cooling system.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Remove the cooling fan assembly and the drive belt. Remove the alternator and bracket.
    2.  
    3. Remove the upper radiator hose and heater hose(s).
    4.  
    5. Remove the air cleaner and intake duct.
    6.  
    7. Label and disconnect the necessary vacuum hoses and electrical connectors.
    8.  
    9. Remove the fuel injector pipe, the clip and the nozzle holder assembly.
    10.  
    11. Remove the glow plugs and sensing resister.
    12.  
    13. If equipped with a turbocharger, remove the turbocharger cover and the turbocharger.
    14.  
    15. Remove the intake and exhaust manifolds from the cylinder head; discard the gaskets.
    16.  
    17. Remove the rocker arm cover, the valve tappet chamber cover and rocker oil feed pipe.
    18.  
    19. Back off the rocker arm adjustments. Remove the rocker arm assembly-to-cylinder head bolts and the rocker arm assembly.
    20.  
    21. Remove the pushrods and keep them in order for reinstallation purposes.
    22.  
    23. Remove the cylinder head-to-engine bolts, a little at a time, by reversing the torquing sequence. Remove the cylinder head; it may be necessary to use a mallet to tap the cylinder head loose from the engine.
    24.  
    25. Match the old gasket to the new cylinder head gasket and clean the gasket mounting surfaces.
    26.  



    Click image to see an enlarged view

    Fig. Rocker arm shaft torque sequence C223 diesel engine, 15 ft. lbs. (20 Nm)



    Click image to see an enlarged view

    Fig. Head gasket positioning C223 diesel engine



    Click image to see an enlarged view

    Fig. Cylinder head torque sequence C223 diesel engine

    To install:

    1. Using a new gasket, position it onto the engine with the work TOP facing upwards.
    2.  
    3. Refill the turbocharger with clean engine oil before installation.
    4.  
    5. Install the cylinder head onto the engine. Lubricate the cylinder head bolts with engine oil and torque them, in sequence, using the following procedure:
    6.  
      1. Turbocharged Engine
      2.  
      3. 1st step: 33 and 1940 ft. lbs. (45 and 1954 Nm)
      4.  
      5. 2nd step: 120 and 19150and#x00B0;
      6.  
      7. Non-turbocharged Engine
      8.  
      9. 1st step: 40 and 1947 ft. lbs. (54 and 1963 Nm)
      10.  
      11. 2nd step: 54 and 1961 ft. lbs. (74 and 1981 Nm) for new bolts or 61 and 1969 ft. lbs. (81 and 1995 Nm) for used bolts.
      12.  

    7. Install the pushrods and make sure they are positioned in the tappets.
    8.  
    9. Install the rocker arm assembly and torque the rocker arm-to-cylinder head bolts to 10 and 1917 ft. lbs. (14 and 1924 Nm) Adjust the valve lash.
    10.  
    11. Using new gaskets, reverse the removal procedures.
    12.  
    13. Refill the cooling system. Connect the negative battery cable. Start the engine and check for leaks.
    14.  

    4FB1 Engine
    1. Drain the cooling system by opening the drain plug on the cylinder block.
    2.  


    CAUTION
    When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

    1. Remove the camshaft.
    2.  
    3. Remove the sensing resistor assembly.
    4.  
    5. Remove the six screws attaching the injection pipe clip and remove the injection pipe clip.
    6.  
    7. Remove the eight sleeve nuts attaching the injection pipes and separate the infection pipes.
    8.  
    9. Remove the clip attaching the fuel leak off hose and separate the hose from the return pipe.
    10.  
    11. Remove the two nuts connecting the exhaust manifold to the exhaust pipe and separate the pipe from the manifold.
    12.  
    13. Disconnect the joint bolt attaching the oil feed line to the head side.
    14.  
    15. Disconnect the heater hose at the thermostat housing pipe.
    16.  
    17. Remove the cylinder head bolts by loosening them in sequence, then remove the cylinder head and gasket.
    18.  


    NOTE
    Use light oil to free stubborn bolts.

    1. Clean the head and block of all gasket material before reassembly.
    2.  



    Click image to see an enlarged view

    Fig. Cylinder head bolt torque sequence 4FB1 diesel engine

    To install:

    1. Match up the old gasket to the new to ensure an exact fit. Install the gasket and cylinder head.
    2.  
    3. Torque all bolts in the sequence given at the front of this section. Apply oil to the bolt threads and clean them thoroughly before reinstalling them in the head. Torque the cylinder head bolts in 2 passes the first pass to 21 and 1936 ft. lbs. (27 and 1948 Nm) and the second pass to 83 and 1998 ft. lbs. (112 and 19135 Nm). Torque the reused bolts to 90 and 19105 ft. lbs. (122 and 19140 Nm).
    4.  


    NOTE
    Make sure that the cylinder head gasket is properly placed before lowering the head. Look for the TOP mark to assure proper placement.

    1. Reinstall the camshaft and rocker arm assembly. Reinstall the timing belt and adjust the valve clearance.
    2.  
    3. Start the engine and check for leaks.
    4.  

    CLEANING AND INSPECTION

    Chip carbon away from the valve heads, combustion chambers, and ports, using a chisel made of hardwood. Remove the remaining deposits with a stiff wire brush.


    NOTE
    Be sure that the deposits are actually removed, rather than burnished.

    Have the cylinder head hot-tanked to remove grease, corrosion, and scale from the water passages. Clean the remaining cylinder head parts in an engine cleaning solvent. Do not remove the protective coating from the springs.


    WARNING
    Aluminum cylinder head can not be hot-tanked in the same solution that is used for cast iron. Make sure the machine shop knows if the cylinder heads are aluminum.

    Place a straightedge across the gasket surface of the cylinder head. Using feeler gauges, determine the clearance at the center of the straightedge. If warpage exceeds 0.08mm (0.003 in.) in a 152mm (6 in.) span, or 0.15mm (0.006 in.) over the total length, the cylinder head must be resurfaced.


    NOTE
    If warpage exceeds the manufacturer's maximum tolerance for material removal, the cylinder head must be replaced.

    When milling the cylinder heads of V-type engines, the intake manifold mounting position is altered, and must be corrected by milling the manifold flange a proportionate amount.



    Click image to see an enlarged view

    Fig. Remove the carbon from the cylinder head with a wire brush and electric drill



    Click image to see an enlarged view

    Fig. Check the cylinder head for warpage

    RESURFACING

    This procedure should be performed only by a machine shop.

     
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