Nissan Sentra/Pulsar/NX 1982-1996 Repair Guide

Cylinder Head

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REMOVAL & INSTALLATION



To prevent distortion or warping of the cylinder head, allow the engine to cool completely before removing the head bolts.

E-Series Engines Except E16i

See Figures 1, 2, 3 and 4



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Fig. Fig. 1: Three size head bolts are used. Note the locations during removal-E-Series engines



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Fig. Fig. 2: Cylinder head bolt loosening sequence-E-Series engines



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Fig. Fig. 3: If cupped washers are used, make certain they are installed in the correct direction-E-Series engines



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Fig. Fig. 4: Cylinder head bolt tightening sequence-E-Series engines

If the engine mounting bracket must be removed. Support the engine by placing a jack or equivalent, with a wooden block on top, under the oil pan away from the oil drain plug.

  1. Crank the engine until the No. 1 piston is at Top Dead Center on its compression stroke and disconnect the negative (-) battery cable.
  2.  
  3. Drain the cooling system.
  4.  


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

  1. Remove the air cleaner assembly.
  2.  
  3. Remove the alternator and all drive belts.
  4.  
  5. Number all spark plug wires as to their respective cylinders, mark and remove the distributor, with all wires attached.
  6.  
  7. Remove the EAI pipes bracket and EGR tube at the right (EGR valve) side. Disconnect the same pipes on the front (exhaust manifold) side from the manifold.
  8.  
  9. Remove the exhaust manifold cover and the exhaust manifold, taking note that the center manifold nut has a different diameter than the other nuts.
  10.  
  11. Remove the air conditioning compressor bracket and the power steering pump bracket (if equipped).
  12.  
  13. Label and disconnect the carburetor throttle linkage, fuel line, and all vacuum and electrical connections.
  14.  
  15. Remove the intake manifold with carburetor or throttle body.
  16.  
  17. Remove the water pump pulley and crankshaft pulley.
  18.  
  19. Remove the rocker (valve) cover.
  20.  
  21. Remove upper and lower dust cover on the camshaft timing belt shroud.
  22.  
  23. With the shroud removed, the cam sprocket, crankshaft sprocket, jackshaft sprocket, tensioner pulley, and toothed rubber timing belt are exposed.
  24.  
  25. Mark the relationship of the camshaft sprocket to the timing belt and the crankshaft sprocket to the timing belt with paint or a grease pencil. This will make setting everything up during reassembly much easier if the engine is disturbed during disassembly.
  26.  
  27. Remove the belt tensioner pulley.
  28.  
  29. Mark an arrow on the timing belt showing direction of engine rotation, because the belt wears a certain way and should be installed the way it was removed. Slide the belt off the sprockets.
  30.  
  31. Carefully remove the cylinder head from the block, pulling the head up evenly from both ends. If the head seems stuck, DO NOT pry it off. Tap lightly around the lower perimeter of the head with a rubber mallet to help break the seal. Label all head bolts with tape, as they must go back in their original positions. On some engines bolts are different size.
  32.  

To install:
  1. Thoroughly clean both the cylinder block and head mating surfaces. Avoid scratching either.
  2.  
  3. Turn the crankshaft and set the No. 1 cylinder at TDC on its compression stroke. This causes the crankshaft timing sprocket mark to be aligned with the cylinder block cover mark.
  4.  
  5. Align the camshaft sprocket mark with the cylinder head cover mark. This causes the valves for No. 1 cylinder to position at TDC on the compression stroke.
  6.  
  7. Place a new gasket on the cylinder block.
  8.  

If cupped washers are used for installation, always make sure that the flat side of the washer is facing downward before tightening the cylinder head bolts.

  1. Install the cylinder head on the block and tighten the bolts in stages: first tighten all bolts to 22 ft. lbs. (30 Nm), then retighten them all to 51 ft. lbs. (69 Nm). Next, loosen all bolts completely, and then retighten them again to 22 ft. lbs. (30 Nm). Tighten all bolts to a final torque of 51-54 ft. lbs. (69-74 Nm).
  2.  
  3. Install the timing belt, tensioner, upper and lower dust cover. Make sure all timing marks are in proper alignment. Connect the engine mount bracket.
  4.  
  5. Install the valve cover, water pump drive belt and pulley. Install the crankshaft pulley.
  6.  
  7. Install the intake manifold with carburetor or throttle body.
  8.  
  9. Connect the carburetor throttle linkage, fuel line, and all vacuum and electrical connections.
  10.  
  11. Install the air conditioning compressor bracket and the power steering pump bracket (if equipped).
  12.  
  13. Install the exhaust manifold and the exhaust manifold cover.
  14.  
  15. Connect all emission pipes and brackets and any other interfering parts that were removed.
  16.  
  17. Install distributor and spark plug wires.
  18.  
  19. Install the alternator, drive belts and the air cleaner assembly.
  20.  
  21. Refill cooling system, adjust the drive belts, start engine, check timing and for coolant or oil leaks.
  22.  
  23. Road test the vehicle.
  24.  

CA16DE and CA18DE Engines

See Figures 5, 6, 7, 8 and 9



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Fig. Fig. 5: Support the engine with a block of wood and jack, before removing supports



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Fig. Fig. 6: Crank angle sensor is located on the timing cover-CA16DE and CA18DE engines



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Fig. Fig. 7: Cylinder head bolt loosening and tightening sequence-CA16DE and CA18DE engines



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Fig. Fig. 8: Breather separator mounting-CA16DE and CA18DE engines



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Fig. Fig. 9: Cupped washer installation-CA16DE and CA18DE engines

  1. Crank the engine until the No. 1 piston is at Top Dead Center on its compression stroke.
  2.  
  3. Disconnect the negative (-) battery cable.
  4.  
  5. Drain the cooling system and remove the air cleaner assembly and upper radiator hose.
  6.  


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

  1. Loosen the alternator and remove all drive belts. Remove the alternator. If necessary remove the right side under cover.
  2.  
  3. Disconnect the air duct at the throttle chamber.
  4.  
  5. Tag and disconnect all lines, hoses and wires which may interfere with cylinder head removal.
  6.  
  7. Remove the 8 screws and lift off the ornament cover.
  8.  
  9. Disconnect the O 2 sensor.
  10.  
  11. Remove the 2 exhaust heat shield covers.
  12.  
  13. Unbolt the exhaust manifold and wire the entire assembly out of the way.
  14.  
  15. Disconnect the EGR tube at the passage cover and then remove the passage cover and its gasket.
  16.  
  17. Disconnect and remove the crank angle sensor from the upper front cover.
  18.  

Put aligning mark on crank angle sensor and timing belt cover.

  1. Remove the support stay from under the intake manifold assembly.
  2.  
  3. Unbolt the intake manifold and remove it along with the collector and throttle chamber.
  4.  
  5. Disconnect and remove the fuel injectors as an assembly.
  6.  
  7. Remove the upper and lower front covers.
  8.  

Remove engine mount bracket but support engine under oil pan with wooden blocks or equivalent. Do not position the support near the drain plug.

  1. Remove the timing belt and camshaft sprockets.
  2.  

When the timing belt has been removed, NEVER rotate the crankshaft and camshaft separately because the valves will hit the pistons!

  1. Remove the camshaft cover.
  2.  
  3. Remove the breather separator.
  4.  
  5. Gradually loosen the cylinder head bolts in several stages, in the sequence illustrated.
  6.  
  7. Carefully remove the cylinder head from the block, pulling the head up evenly from both ends. If the head seems stuck, DO NOT pry it off. Tap lightly around the lower perimeter of the head with a rubber mallet to help break the seal. Label all head bolts with tape or magic marker, as they must go back in their original positions.
  8.  

To install:
  1. Thoroughly clean both the cylinder block and head mating surfaces. Avoid scratching either.
  2.  
  3. Install the cylinder head with bolts on the block. When installing the bolts tighten the two center bolts temporarily to 15 ft. lbs. (20 Nm) and install the head bolts loosely. After the timing belt and front cover have been installed, torque all the head bolts in the torque sequence. Tighten all bolts to 22 ft. lbs. (30 Nm). Re-tighten all bolts to 76 ft. lbs. (103 Nm). Loosen all bolts completely and then re-tighten them once again to 22 ft. lbs. (30 Nm). Tighten all bolts to a final torque of 76 ft. lbs. ((103 Nm).
  4.  

If cupped washers are used for installation, always make sure that the flat side of the washer is facing downward before tightening the cylinder head bolts.

  1. Install the camshaft sprocket, timing belt and front covers.
  2.  
  3. Reconnect the engine mount support.
  4.  
  5. Install the fuel injectors, intake manifold assembly with collector and throttle chamber attached.
  6.  
  7. Connect the support stay to the intake manifold.
  8.  
  9. Install the crank angle sensor. Align the sensor with mark that was made before removal.
  10.  
  11. Connect EGR tube and passage cover with a new gasket.
  12.  
  13. Install the exhaust manifold assembly and heat shields.
  14.  
  15. Reconnect the O 2 sensor and ornament cover.
  16.  
  17. Reconnect the air duct at the throttle chamber. Connect all lines, hoses and wires that were removed.
  18.  
  19. Install the alternator and adjust all the drive belts.
  20.  
  21. Install the air cleaner assembly.
  22.  
  23. Refill cooling system, start engine, check timing and for coolant or oil leaks.
  24.  
  25. Road test the vehicle.
  26.  

1983-86 Diesel Engine

See Figures 10 and 11



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Fig. Fig. 10: Cylinder head bolt loosening sequence-CD17 diesel



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Fig. Fig. 11: Cylinder head bolt tightening sequence-CD17 diesel

  1. Disconnect the battery.
  2.  
  3. Drain the coolant.
  4.  


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

  1. Disconnect the exhaust pipe.
  2.  
  3. Set the No. 1 cylinder at TDC on the compression stroke. Tag and disconnect all hoses and electrical connections.
  4.  
  5. Remove the valve timing belt on the camshaft pulley side of the engine.
  6.  
  7. Remove the rear engine cover.
  8.  
  9. Remove the injection pump timing belt.
  10.  
  11. Loosen the injection pump pulley and remove it with a suitable puller.
  12.  
  13. Tag and removal the fuel injection lines from the injectors.
  14.  
  15. Remove the camshaft (valve) cover and loosen the cylinder head bolts in the reverse of the torque sequence given in this section.
  16.  
  17. Remove the cylinder head, with the manifolds still attached. If the head will not budge, tap around the head-to-block mating surface with a rubber mallet. The manifolds can be removed on a bench.
  18.  

To install:
  1. Head gaskets are selected by measuring the piston projection. Clean and inspect the head as described in this section. Then, once the proper gasket has been selected, install the gasket and head.
  2.  
  3. Lightly oil the head bolt threads and underside of the heads and install with washers. Torque the head bolts as follows:
    1. Torque all the bolts in the sequence shown to 29 ft. lbs. (39 Nm).
    2.  
    3. Torque all the bolts in the sequence shown to 72-79 ft. lbs. (98-107 Nm).
    4.  
    5. Loosen all the bolts completely.
    6.  
    7. Torque all the bolts in the sequence shown to 29 ft. lbs. (39 Nm).
    8.  
    9. If you do not have an angle type wrench, torque all the bolts in the sequence shown to 72-79 ft. lbs. (98-107 Nm). If you do have an angle wrench, turn each bolt, in the sequence shown, 82-87 degrees farther.
    10.  

  4.  
  5. Adjust the valves as described in Engine Electrical . Install the cam cover as described above.
  6.  
  7. Install the injection lines as described in Fuel System .
  8.  
  9. Install the injection pump drive pulley. Then, install the pump timing belt as described later in this section.
  10.  
  11. Install the rear timing belt cover.
  12.  
  13. Install the front engine timing belt and belt cover.
  14.  
  15. Connect all hoses and electrical connections according to the tags made earlier.
  16.  
  17. Connect the exhaust pipe. Refill the cooling system. Connect the battery. Start the engine and check for leaks.
  18.  

1987-88 E16i Engine

See Figures 12, 13, 14 and 15



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Fig. Fig. 12: Cylinder head bolt loosening sequence-E16i engine



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Fig. Fig. 13: Three size head bolts are used. Note the locations during removal-E-Series engines



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Fig. Fig. 14: Cylinder head bolt tightening sequence-E16i engine



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Fig. Fig. 15: Make certain the cutout on the E-Series rocker shaft faces the exhaust manifold-E-Series engines

Be sure to use new washers when installing the cylinder head bolts.

  1. Crank the engine until the No. 1 piston is at TDC on its compression stroke.
  2.  
  3. Relieve the fuel system pressure, as described in Fuel System .
  4.  
  5. Disconnect the negative (-) battery cable.
  6.  
  7. Drain the cooling system and remove the air cleaner assembly.
  8.  


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

  1. Remove the alternator.
  2.  
  3. Remove the distributor, with all wires attached.
  4.  
  5. Remove the EAI pipe bracket and EGR tube at the right (EGR valve) side. Disconnect the same pipes on the front side of the manifold.
  6.  
  7. Remove the exhaust manifold cover and the exhaust manifold, taking note that the center manifold nut has a different diameter than the other nuts. Label this nut to ensure proper installation.
  8.  
  9. Remove the air conditioning compressor bracket and power steering pump bracket, if equipped.
  10.  
  11. Disconnect the carburetor throttle linkage, fuel line, and all vacuum and electrical connections.
  12.  
  13. Remove the intake manifold.
  14.  
  15. Remove water pump drive belt and pulley.
  16.  
  17. Remove crankshaft pulley.
  18.  
  19. Remove the rocker (valve) cover.
  20.  
  21. Remove upper and lower dust cover on the camshaft timing belt shroud.
  22.  
  23. Mark the relationship of the camshaft sprocket to the timing belt and the crankshaft sprocket to the timing belt with paint or a grease pencil. This will make setting everything up during reassembly much easier if the engine is disturbed during disassembly.
  24.  
  25. Remove the belt tensioner pulley.
  26.  
  27. Mark an arrow on the timing belt showing direction of engine rotation and slide the belt off the sprockets.
  28.  
  29. Loosen the head bolts in reverse of the tightening sequence and carefully remove the cylinder head from the block, pulling the head up evenly from both ends. If the head seems stuck, do not pry it off. Tap lightly around the lower perimeter of the head with a rubber mallet to help break the seal. Label all head bolts with tape, as they must go back in their original positions.
  30.  

To install:
  1. Thoroughly clean both the cylinder block and head mating surfaces. Avoid scratching either.
  2.  
  3. Turn the crankshaft and set the No. 1 cylinder at TDC on its compression stroke. This causes the crankshaft timing sprocket mark to be aligned with the cylinder block cover mark.
  4.  
  5. Align the camshaft sprocket mark with the cylinder head cover mark. This causes the valves for No. 1 cylinder to position at TDC on the compression stroke.
  6.  
  7. Place a new gasket on the cylinder block.
  8.  

There are 3 different size head bolts used on the E16i engine. Bolt (A) is 3.74 in. (95mm), bolt (B) is 4.33 in. (110mm) and bolt (C) is 3.15 in. (80mm). Measure the length of each bolt prior to installation and make sure they are installed in their proper locations on the head.

  1. Install the cylinder head on the block and tighten the bolts as follows:
    1. Tighten all bolts to 22 ft. lbs. (29 Nm), then retighten them all to 51 ft. lbs. (69 Nm).
    2.  
    3. Loosen all bolts completely, and then retighten them again to 22 ft. lbs. (29 Nm).
    4.  
    5. Tighten all bolts to a final torque of 51-54 ft. lbs. (69-74 Nm); if an angle wrench is used, turn each bolt until they have achieved the specified number of degrees-bolts 1, 3, 6, 8 and 9: 45-50°; bolt 7: 55-60°; bolts 2, 4, 5 and 10: 40-45°.
    6.  

  2.  
  3. Install the timing belt.
  4.  
  5. Install the upper and lower dust covers on the camshaft timing belt shroud.
  6.  
  7. Install the rocker arm cover.
  8.  
  9. Install the crankshaft pulley, water pump pulley and drive belt.
  10.  
  11. Install the intake manifold.
  12.  
  13. Connect the throttle linkage, fuel line, and all vacuum and electrical connections.
  14.  
  15. Install the air conditioning compressor bracket and the power steering pump bracket, if equipped.
  16.  
  17. Install the exhaust manifold and exhaust manifold cover. Make sure the center manifold nut, which has a different diameter, is installed in the proper location.
  18.  
  19. Connect the EAI exhaust pipes and tubing.
  20.  
  21. Install the distributor and connect the spark plug wiring.
  22.  
  23. Install the alternator and air cleaner.
  24.  
  25. Fill the cooling system to the proper level and connect the negative (-) battery cable.
  26.  
  27. Make all the necessary engine adjustments. Road test the vehicle for proper operation.
  28.  

GA16i Engine

See Figures 16, 17, 18 and 19



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Fig. Fig. 16: Cylinder head bolt loosening sequence-GA16i engine



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Fig. Fig. 17: Cylinder head bolt tightening sequence-GA16i engine



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Fig. Fig. 18: When the camshaft is aligned as shown, the No. 1 cylinder is at TDC-GA16i engine



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Fig. Fig. 19: When the crankshaft is marks are aligned as shown, the No. 1 cylinder is at TDC-GA16i engine

  1. Relieve the fuel system pressure, as described in Fuel System .
  2.  
  3. Disconnect the negative (-) battery.
  4.  
  5. Drain the cooling.
  6.  


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

  1. Disconnect the exhaust tube from the exhaust manifold.
  2.  
  3. Remove the intake manifold support bracket.
  4.  
  5. Remove the air cleaner assembly.
  6.  
  7. Disconnect the center wire from the distributor cap.
  8.  
  9. Remove the rocker arm cover.
  10.  
  11. Remove the distributor.
  12.  
  13. Remove the spark plugs.
  14.  
  15. Set the No. 1 cylinder at TDC of the compression stroke by rotating the engine until the cut out machined in the rear of the camshaft is horizontally aligned with the cylinder head.
  16.  
  17. Hold the camshaft sprocket stationary with the proper tool and loosen the sprocket bolt. Place highly visible and accurate paint or chalk alignment marks on the camshaft sprocket and the timing chain, then slide the sprocket from the camshaft and lift the timing chain from the sprocket. Remove the sprocket. The timing chain will not fall off the crankshaft sprocket unless the front cover is removed. This is due to the cast portion of the front cover located on the lower side of the crankshaft sprocket which acts a stopper mechanism. For this reason a chain stopper (wedge) is not required to remove the cylinder head.
  18.  
  19. Loosen the cylinder bolts in 2-3 stages to prevent warpage and cracking of the head. One of the cylinder head bolts is longer than the rest. Mark this bolt and make a note of its location.
  20.  
  21. Carefully remove the cylinder head from the block, pulling the head up evenly from both ends. If the head seems stuck, do not pry it off. Tap lightly around the lower perimeter of the head with a rubber mallet to help break the seal. The cylinder head and the intake and exhaust manifolds are removed together. Remove the cylinder head gasket.
  22.  

To install:
  1. Thoroughly clean both the cylinder block and head mating surfaces. Avoid scratching either.
  2.  
  3. Turn the crankshaft and set the No. 1 cylinder at TDC on its compression stroke. This is done by aligning the timing pointer with the appropriate timing mark on the pulley. To ensure that the No. 1 piston is at TDC, verify that the knock pin in the front of the camshaft is set at the top.
  4.  
  5. Place a new gasket on the block and lower the head onto the gasket.
  6.  

These engines use different length cylinder head bolts. Bolt (1) is longer than the rest. Bolt (1) is 5.24 in. (133mm) while bolts (2) through (10) are 4.33 in. (110mm). Do not confuse the location of these bolts.

  1. Coat the threads and the seating surface of the head bolts with clean engine oil and use a new set of washers. Install the cylinder head bolts in their proper locations and tighten as follows:
    1. Tighten all the bolts in sequence to 22 ft. lbs. (30 Nm).
    2.  
    3. Tighten all bolts in sequence to 47 ft. lbs. (64 Nm).
    4.  
    5. Loosen all bolts in reverse of the tightening sequence.
    6.  
    7. Tighten all bolts again to 22 ft. lbs. (30 Nm).
    8.  
    9. If an angle torque wrench is not available, torque the bolts in sequence to 43-51 ft. lbs. (58-69 Nm). If using an angle torque wrench for this step, tighten bolt (1) 80-85 degrees clockwise and bolts (6) through (10) 60-65 degrees clockwise.
    10.  
    11. Finally, tighten bolts (11) through (15) to 55-73 inch lbs. (6.3-8.3 Nm).
    12.  

  2.  
  3. Place the timing chain on the camshaft sprocket using the alignment marks. Slide the sprocket and timing chain onto the camshaft and install the center bolt.
  4.  
  5. At this point, check the hydraulic valve lifters for proper operation pushing hard on each lifter hard with fingertip pressure. Make sure the rocker arm arm is not on the cam lobe when making this check. If the valve lifter moves more than 0.04 in. (1mm), air may be inside it.
  6.  
  7. Install the spark plugs.
  8.  
  9. Install the distributor.
  10.  
  11. Install the rocker arm cover.
  12.  
  13. Connect the center wire to the distributor cap.
  14.  
  15. Install the air cleaner assembly.
  16.  
  17. Install the intake manifold support bracket.
  18.  
  19. Fill the cooling system to the proper level and connect the negative (-) battery cable.
  20.  
  21. Make all the necessary engine adjustments. If there was air in the lifters, bleed the air by running the engine at 1000 rpm for 10 minutes. Road test the vehicle for proper operation.
  22.  

GA16DE Engine

See Figures 20, 21, 22, 23, 24, 25, 26, 27, 28 and 29



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Fig. Fig. 20: The timing chain must be removed before performing cylinder head service



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Fig. Fig. 21: Camshaft assembly bolt loosening sequence-GA16DE engine



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Fig. Fig. 22: Cylinder head bolt loosening sequence-GA16DE engine



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Fig. Fig. 23: After all components have been removed, the cylinder head can be lifted off of the block



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Fig. Fig. 24: Before removing the cylinder head gasket, examine the area for cracks or signs of leakage



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Fig. Fig. 25: Removing the cylinder head gasket



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Fig. Fig. 26: With rags placed into the cylinders to keep them clean, scrap all old gasket material from the block



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Fig. Fig. 27: Make sure to install washers the between bolts and cylinder heads



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Fig. Fig. 28: Cylinder head bolt tightening sequence-GA16DE engine



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Fig. Fig. 29: The cylinder head bolts must be tightened with a torque wrench in the proper order

This is a very complex procedure. Before attempting cylinder head service thoroughly review these procedures, as well as the steps required for timing chain and camshaft service. To avoid head gasket leaks later you, should use new cylinder head bolts.

  1. Relieve the fuel system pressure as described in Fuel System .
  2.  
  3. Disconnect the negative (-) battery cable.
  4.  
  5. Drain the cooling system.
  6.  


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

  1. Remove all drive belts. Disconnect the exhaust tube from the exhaust manifold.
  2.  
  3. Remove the power steering bracket.
  4.  
  5. Remove the air duct to intake manifold collector.
  6.  
  7. Remove the front right side wheel, splash cover and front under covers.
  8.  
  9. Remove the front exhaust pipe and engine front mounting bracket.
  10.  
  11. Remove the rocker arm cover.
  12.  
  13. Remove the distributor cap. Remove the spark plugs.
  14.  
  15. Set the No. 1 cylinder at TDC of the compression stroke.
  16.  
  17. Mark and remove the distributor assembly.
  18.  
  19. Remove the cam sprocket cover and gusset. Remove the water pump pulley. Remove the thermostat housing.
  20.  
  21. Remove the chain tensioner, chain guide. Loosen idler sprocket bolt.
  22.  
  23. Remove the camshaft sprocket bolts, camshaft sprocket, camshaft brackets and camshafts. Remove the idler sprocket bolt. These parts should be reassembled in their original position. Bolts should be loosen in 2 or 3 steps.
  24.  
  25. Loosen the cylinder bolts in 2-3 stages to prevent warpage and cracking of the head and note location of all head bolts.
  26.  
  27. Carefully remove the cylinder head from the block, pulling the head up evenly from both ends. If the head seems stuck, do not pry it off. Tap lightly around the lower perimeter of the head with a rubber mallet to help break the seal. The cylinder head and the intake and exhaust manifolds are removed together. Remove the cylinder head gasket.
  28.  

To install:
  1. Thoroughly clean both the cylinder block and head mating surfaces. Avoid scratching either.
  2.  
  3. Coat the threads and the seating surface of the head bolts with clean engine oil, and use a new set of washers as necessary. Install the cylinder head assembly (always replace the head gasket). Install head bolts (with washers) in their proper locations and tighten as follows:
    1. Tighten all the bolts in sequence to 22 ft. lbs. (29 Nm).
    2.  
    3. Tighten all bolts in sequence to 43 ft. lbs. (59 Nm).
    4.  
    5. Loosen all bolts in reverse of the tightening sequence.
    6.  
    7. Tighten all bolts again in sequence to 22 ft. lbs. (29 Nm).
    8.  
    9. Tighten bolts to 50-55 degrees clockwise in sequence or if angle wrench is not available, tighten bolts to 40-46 ft. lbs. (54-62 Nm) in sequence.
    10.  
    11. Finally, tighten bolts (11) through (15) to 55-73 inch lbs. (6.3-8.3 Nm).
    12.  

  4.  
  5. Install the camshaft assembly as outlined in this section, if necessary.
  6.  
  7. Install the upper timing chain assembly.
  8.  
  9. Install all other components in the reverse order of the removal procedure. Refill and check all fluid levels. Road test the vehicle for proper operation.
  10.  

SR20DE Engine

See Figures 30, 31, 32, 33, 34 and 35



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Fig. Fig. 30: Camshaft assembly bolt loosening sequence-SR20DE engine



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Fig. Fig. 31: Cylinder head bolt loosening sequence-SR20DE engine



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Fig. Fig. 32: Don't forget the smaller cylinder head bolts-SR20DE engine



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Fig. Fig. 33: Cylinder head bolt tightening sequence-SR20DE engine



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Fig. Fig. 34: Mark the side of each bolt with paint, then final turn each bolt 90-100 degrees. Follow the cylinder head bolt tightening sequence-SR20DE engine



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Fig. Fig. 35: The camshaft sprocket position must be accurate-SR20DE engine

This is a very complex procedure. Before attempting cylinder head service thoroughly review these procedures, as well as the steps required for timing chain and camshaft service. These are torque-to-yield-design head bolts. To avoid head gasket leaks later, you should use new cylinder head bolts.

  1. Release the fuel pressure, as outlined in Fuel System .
  2.  
  3. Disconnect the negative (-) battery cable.
  4.  
  5. Raise and safely support the vehicle. Remove the engine under covers.
  6.  
  7. Remove the front right wheel and engine side cover.
  8.  
  9. Drain the cooling system.
  10.  


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

  1. Remove the radiator assembly.
  2.  
  3. Remove the air duct to intake manifold.
  4.  
  5. Remove the drive belts and water pump pulley.
  6.  
  7. Remove the alternator and power steering pump.
  8.  
  9. Remove all vacuum hoses, fuel hoses, wires, electrical connections.
  10.  
  11. Remove all spark plugs.
  12.  
  13. Remove the A.I.V. valve and resonator.
  14.  
  15. Remove the rocker cover and oil separator.
  16.  
  17. Remove the intake manifold supports, oil filter bracket and power steering bracket.
  18.  
  19. Set No. 1 at TDC on the compression stroke. Rotate crankshaft until mating marks on camshaft sprockets are in the correct position.
  20.  
  21. Remove the timing chain tensioner.
  22.  
  23. Mark and remove the distributor assembly. Remove the timing chain guide and camshaft sprockets.
  24.  
  25. Remove the camshafts, camshaft brackets, oil tubes and baffle plate. Keep all parts in order for correct installation.
  26.  
  27. Remove the water hose from the cylinder block and water hose from the heater.
  28.  
  29. Remove the starter motor. Remove the water pipe bolt.
  30.  
  31. Remove the cylinder outside bolts. Remove the cylinder head bolts in 2 or 3 steps. Remove the cylinder head completely with manifolds attached.
  32.  

To install:
  1. Check all components for wear. Replace as necessary. Clean all mating surfaces and replace the cylinder head gasket.
  2.  

You SHOULD use new cylinder head bolts. If the length of any cylinder head bolt exceeds 6.228 in. (158.2mm) you MUST replace the bolts.

  1. Install cylinder head. Tighten cylinder head in the following sequence:
    1. Tighten all bolts in sequence to 29 ft. lbs. (39 Nm).
    2.  
    3. Tighten all bolts in sequence to 58 ft. lbs. (79 Nm).
    4.  
    5. Loosen all bolts in sequence completely.
    6.  
    7. Tighten all bolts in sequence to 25-33 ft. lbs. (34-45 Nm).
    8.  
    9. Tighten all bolts to 90 to 100 degrees clockwise in sequence
    10.  
    11. Tighten all bolts additional 90 to 100 degrees clockwise in sequence. Do not turn any bolt 180 to 200 degrees clockwise all at once.
    12.  

  2.  
  3. Install all other components in the reverse order of the removal procedure. Refill and check all fluid levels. Road test the vehicle for proper operation.
  4.  

CLEANING AND INSPECTION



See Figures 36 and 37



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Fig. Fig. 36: Check the cylinder head for warpage from end-to-end, across and diagonally



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Fig. Fig. 37: Check the cylinder head for warpage along the center using a straightedge and a feeler gauge

  1. With the valves installed to protect the valve seats, remove carbon deposits from the combustion chambers and valve heads with a drill-mounted wire brush. Be careful not to damage the cylinder head gasket surface. If the head is to be disassembled, proceed to Step 3. If the head is not to be disassembled, proceed to Step 2.
  2.  

You should have the cylinder cleaned at a machine shop 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.

  1. Remove all dirt, oil and old gasket material from the cylinder head with solvent. Clean the bolt holes and the oil passage. Be careful not to get solvent on the valve seals as the solvent may damage them. If available, dry the cylinder head with compressed air. Check the head for cracks or other damage, and check the gasket surface for burrs, nicks and flatness. If you are in doubt about the head's serviceability, consult a reputable automotive machine shop.
  2.  
  3. Remove the valves, springs and retainers, then clean the valve guide bores with a valve guide cleaning tool. Remove all dirt, oil and old gasket material from the cylinder head with solvent. Clean the bolt holes and the oil passage.
  4.  
  5. Remove all deposits from the valves with a wire brush or buffing wheel. Inspect the valves, as described later in this section.
  6.  
  7. Check the head for cracks using a dye penetrant in the valve seat area and ports, head surface and top. Check the gasket surface for burrs, nicks and flatness. If you are in doubt about the head's serviceability, consult a reputable automotive machine shop.
  8.  

If the cylinder head was removed due to an overheating condition and a crack is suspected, do not assume that the head is not cracked because a crack is not visually found. A crack can be so small that it cannot be seen by eye, but can pass coolant when the engine is at operating temperature. Consult an automotive machine shop that has pressure testing equipment to make sure the head is not cracked.

RESURFACING



Whenever the cylinder head is removed, check the flatness of the cylinder head gasket surface as follows:

  1. Make sure all dirt and old gasket material has been cleaned from the cylinder head. Any foreign material left on the head gasket surface can cause a false measurement.
  2.  
  3. Place a straightedge straight across and diagonally across the gasket surface of the cylinder head (in the positions shown in the figures). Using feeler gauges, determine the clearance at the center of the straightedge.
  4.  
  5. If warpage exceeds the 0.004 in. (0.10mm) then the cylinder head should likely be resurfaced or replaced. Cylinder head resurfacing should be done only by a competent machine shop. If warpage exceeds the manufacturer's tolerance, the cylinder head must be replaced.
  6.  

 
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