ISUZU Amigo/Pick-ups/Rodeo/Trooper 1981-1996

Rocker Arms/Shafts

Imprimir

REMOVAL & INSTALLATION



4-Cylinder Gasoline Engines
EXCEPT 2.2L ENGINE

See Figures 1, 2, 3 and 4



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Fig. Fig. 1: Rocker arm and shaft assembly exploded view-4-cylinder gasoline engine



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Fig. Fig. 2: Rocker arm assembly-4-cylinder gasoline engine



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Fig. Fig. 3: Rocker arm shaft installation-4-cylinder gasoline engine



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Fig. Fig. 4: Rocker arm bolt torque sequence-4-cylinder gasoline engine

  1. Disconnect the negative battery cable. Remove the rocker cover.
  2.  
  3. Loosen the rocker arm shaft bracket nuts a little at a time, in sequence, starting with the outer nuts.
  4.  
  5. Remove the nuts from the rocker arm shaft brackets. Remove shaft assembly.
  6.  
  7. To disassemble the rockers and shafts; remove the spring from the rocker arm shaft, the rocker brackets and arms. Keep parts in order for reassembly.
  8.  
  9. Before installing apply a generous amount of clean engine oil to the rocker arm shaft, rocker arms and valve stems.
  10.  

To install:
  1. Install the longer shaft on the exhaust valve side and the shorter shaft on the intake side so the aligning marks on the shafts are turned on the front side of the engine.
  2.  
  3. Assemble the rocker arm shaft brackets and rocker arms to the shafts so the cylinder number, on the upper face of the brackets, points toward the front of the engine.
  4.  
  5. Align the mark on the No. 1 rocker arm shaft bracket with the mark on the intake and exhaust valve side rocker arm shaft.
  6.  
  7. Make certain the amount of projection of the rocker arm shaft beyond the face of the No. 1 rocker arm shaft bracket, is longer on the exhaust side shaft than on the intake shaft when the rocker arm shaft stud holes are aligned with the rocker arm shaft bracket stud holes.
  8.  
  9. Place the rocker arm shaft springs in position between the shaft bracket and rocker arm.
  10.  
  11. Check that the punch mark on the rocker arm shaft is facing upward, then, install the rocker arm shaft bracket assembly onto the cylinder head studs. Align the mark on the camshaft with the mark on the No. 1 rocker arm shaft bracket.
  12.  
  13. Torque the rocker arm shaft brackets-to-cylinder head nuts to 16 ft. lbs. (21 Nm) and bolts to 72 inch lbs. (8 Nm).
  14.  

Hold the rocker arm springs while tightening the nuts to prevent damage to the spring. Start with the center nut and work outward.

  1. Adjust the valves as outlined in General Information & Maintenance . Install the rocker arm cover, with a new gasket and sealer. Check the ignition timing.
  2.  

2.2L ENGINE
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the rocker arm covers.
  4.  
  5. Remove the rocker arm nut, the pivot balls, the rocker arm and the pushrods. Keep all components separated so they may be reinstalled in the same location.
  6.  

To install:
  1. Install the pushrods in their original location; be sure the lower ends are seated in the lifter.
  2.  
  3. Coat the bearing surfaces of the rocker arms and pivot balls with Molykote® or equivalent.
  4.  
  5. Install the rocker arm nuts and torque them to 20 ft. lbs. (27 Nm).
  6.  

Diesel Engine

See Figures 5 and 6



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Fig. Fig. 5: Bolt loosening sequence for removing rocker arm assembly-diesel engine



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Fig. Fig. 6: Rocker arm assembly-diesel engine

  1. Disconnect the negative (-) battery cable. Remove the cam cover.
  2.  
  3. Loosen the rocker arm shaft bracket nuts a little at a time, in sequence, commencing with the outer brackets.
  4.  
  5. Remove the nuts from the rocker arm shaft brackets.
  6.  
  7. Disassemble the rocker arm shaft assembly by removing the spring from the rocker arm shaft and then removing the rocker arm brackets and arms.
  8.  
  9. Inspect the rocker arm shaft for run-out. Support the shaft on V-blocks at each end and check run-out by slowly turning it with the probe of a dial indicator. Replace the shaft with a new one if the run-out exceeds 0.0156 in. (0.4mm). Run-out should not exceed 0.0079 in. (0.2mm).
  10.  
  11. Inspect the rocker arm shaft for wear, replace the shaft if obvious signs of wear are encountered.
  12.  

To install:
  1. Use a liberal amount of clean engine oil to coat the shaft, rocker arms and valve stems. Install the longer shaft on the exhaust valve side, shorter shaft on the intake side, so that the aligning marks on the shafts are turned to the front of the engine.
  2.  
  3. Torque the rocker arm shaft bracket and stud nuts to 15-22 ft. lbs. (20-27 Nm). Hold the rocker arm springs with an adjustable wrench while tightening the nuts to prevent damage to the springs. Torque the nuts a little at a time in sequence, beginning with the center bracket and working outward.
  4.  
  5. Adjust valve clearances, reinstall the cam cover and check for leaks.
  6.  

2.8L and 3.1L Engines

See Figure 7



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Fig. Fig. 7: Rocker arms and cylinder head assembly-2.8L and 3.1L engines

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the rocker arm covers.
  4.  
  5. Remove the rocker arm nut, the pivot balls, the rocker arm and the pushrods. Keep all components separated so they may be reinstalled in the same location.
  6.  

The intake and exhaust pushrods are of different lengths.

To install:
  1. Install the pushrods in their original location; be sure the lower ends are seated in the lifter.
  2.  
  3. Coat the bearing surfaces of the rocker arms and pivot balls with Molykote® or equivalent.
  4.  
  5. Install the rocker arm nuts and tighten until spring use starts to move. Loosen bolt until slight lash is felt. On compression stroke, nut should be turned one and one-half turns after lash is removed.
  6.  
  7. Adjust the valve lash as outlined in General Information & Maintenance .
  8.  

3.2L Engine
1993-95 VEHICLES

See Figures 8, 9, 10, 11, 12, 13, 14 and 15



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Fig. Fig. 8: Camshaft seal repair kit



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Fig. Fig. 9: Rocker arm assembly



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Fig. Fig. 10: Rocker arms and shafts



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Fig. Fig. 11: Measure the shaft at the point where the rocker arm moves on the shaft



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Fig. Fig. 12: Exhaust valve rocker arms



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Fig. Fig. 13: Rocker arm shaft-bolt tightening sequence



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Fig. Fig. 14: Camshaft holder bolt tightening sequence and sealant application points



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Fig. Fig. 15: Timing belt auto tensioner

Isuzu has issued a recall notice for 1993-94 Rodeos equipped with 3.2L engines. This is campaign number 94V-094, and involves faulty camshaft end plugs. The plugs may dislodge from the cylinder heads and can cause rapid oil loss. Remember this when ordering parts: a service kit is available for affected vehicles.

  1. Disconnect negative battery cable.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Disconnect the accelerator pedal cable from the throttle body and cable brackets.
  6.  
  7. Disconnect the canister vacuum hose from the Vacuum Switch Valve (VSV).
  8.  
  9. Disconnect the vacuum booster hose from the common chamber duct.
  10.  
  11. Disconnect the electrical connectors from the Idle Air Control Valve, Throttle Position sensor, Manifold Absolute Pressure sensor, canister VSV, EGR VSV, Intake Air Temperature sensor and VSV.
  12.  
  13. Remove the high tension cable from the cylinder heads.
  14.  
  15. Disconnect the connectors from the ignition module.
  16.  
  17. Remove the three bolts from the electronic ignition bracket and assembly.
  18.  
  19. Remove the four bolts from the throttle body and remove the throttle body.
  20.  
  21. Disconnect the canister VSV and the EGR VSV vacuum hose from the throttle body.
  22.  
  23. Disconnect the fuel pressure control valve vacuum hose from the common chamber duct.
  24.  
  25. Disconnect the PCV hose from the common chamber duct.
  26.  
  27. Disconnect the evaporative emission canister purge hose from the common chamber duct.
  28.  
  29. Remove the four bolts from the EGR valve assembly common chamber duct and remove the exhaust manifold.
  30.  
  31. Remove the four bolts, four nuts and three manifold bracket fixing bolts from the common chamber duct.
  32.  
  33. Remove the ground cable fixing bolt from the rear of the common chamber duct.
  34.  
  35. Remove the six bolts and two nuts from the common chamber duct.
  36.  
  37. Remove the common chamber duct bracket fixing bolts from the rear of the common chamber duct.
  38.  
  39. Remove the following components, and then remove the timing belt:
    1. Remove the upper fan shroud from the radiator.
    2.  
    3. Remove the four nuts retaining the cooling fan assembly. Remove the cooling fan.
    4.  
    5. Remove the power steering drive belt.
    6.  
    7. Remove the air conditioning compressor drive belt.
    8.  
    9. Remove the generator drive belt.
    10.  
    11. Remove the fan pulley assembly.
    12.  
    13. Make sure the timing belt is set at TDC: all the timing marks must align. On 1994-1995 vehicles, the engine will be at TDC/compression for the No. 2 cylinder. On earlier engines, no cylinders are at TDC/compression when the marks are aligned.
    14.  
    15. Remove the crankshaft pulley center bolt. Remove the crankshaft pulley.
    16.  
    17. Remove the two oil cooler hose bracket fixing bolts on the timing cover. Remove the oil cooler hose.
    18.  
    19. Remove the timing belt cover.
    20.  
    21. Remove the pusher. The rod must always be facing upward.
    22.  
    23. Mark the timing belt, cam pulley and crankshaft pulley. Remove the timing belt.
    24.  

  40.  
  41. Remove the cylinder head cover.
  42.  
  43. Remove the camshaft holders and camshaft.
  44.  
  45. Remove the rocker arm shaft bolts. Lift the rocker arm assembly from the cylinder head.
  46.  
  47. The hydraulic lifters are attached to the rocker arms. Remove them and inspect, bleed, or replace as necessary.
  48.  

To install:
  1. Install new camshaft seals and retaining plates onto the cylinder head. Tighten the right camshaft seal retaining plate 6mm bolts to 65 inch lbs. (7.5 Nm). Tighten the left camshaft seal retaining plate 8mm bolts to 191 inch lbs. (21.5 Nm).
  2.  
  3. Install the rocker arm assembly and tighten the bolts in sequence to 13 ft. lbs. (18 Nm).
  4.  
  5. Oil the camshaft bearing journals, camshaft lobes, and rocker arm contact areas.
  6.  
  7. Install the camshaft. Apply sealant to the contact edges of the camshaft holders. Tighten the camshaft 6mm holder bolts to 69 inch lbs. (8 Nm). Tighten the remaining bolts to 13 ft. lbs. (18 Nm).
  8.  
  9. Install the cylinder head covers and carefully tighten the bolts to 69 inch lbs. (8 Nm). Do not overtighten the head cover bolts: they crack very easily.
  10.  
  11. Install the timing belt:
    1. Align the groove on the crankshaft timing pulley with mark on the oil pump.
    2.  
    3. Align the marks on the camshaft timing pulleys with the dots on the front plate.
    4.  
    5. Install the timing belt. Align the dotted marks on the timing belt with the mark on the crankshaft gear.
    6.  
    7. Align the white line on the timing belt with the alignment mark on the right bank camshaft timing pulley. Secure the belt with a double clip.
    8.  
    9. Turn the crankshaft counterclockwise to remove the slack between the crankshaft pulley and the right camshaft timing pulley.
    10.  
    11. Install the belt on the water pump pulley.
    12.  
    13. Install the belt on the idler pulley.
    14.  
    15. Align the white alignment mark on the timing belt with the alignment mark on the left bank camshaft timing pulley.
    16.  
    17. Install the crankshaft pulley and tighten the center bolt by hand. Turn the crankshaft pulley clockwise to give slack between the crankshaft timing pulley and the right bank camshaft timing pulley.
    18.  
    19. Install the pusher while pushing the tension pulley to the belt.
    20.  
    21. Pull the pin out from the pusher.
    22.  
    23. Remove the double clips from the pulleys. Turn the crankshaft pulley clockwise 2 turns. Measure the rod protrusion to be sure it is between 0.16-0.24 in. (4-6mm).
    24.  
    25. Tighten the adjusting bolt to 31 ft. lbs. (42 Nm).
    26.  
    27. Tighten the pusher bolt to 14 ft. lbs. (19 Nm).
    28.  
    29. Remove crankshaft pulley. Install the timing belt cover and tighten bolts to 12 ft. lbs. (17 Nm).
    30.  
    31. Install the oil cooler hose and tighten brackets to 16 ft. lbs. (22 Nm).
    32.  
    33. Install the crankshaft pulley and tighten the bolt to 123 ft. lbs. (167 Nm).
    34.  
    35. Install the fan pulley assembly and tighten the bolts to 16 ft. lbs. (22 Nm).
    36.  
    37. Engage and adjust the alternator drive belt.
    38.  
    39. Engage and adjust the air conditioning drive belt.
    40.  
    41. Engage and adjust the power steering pump drive belt.
    42.  
    43. Install the cooling fan assembly and tighten bolts to 69 inch lbs. (8 Nm).
    44.  
    45. Install the upper fan shroud to the radiator.
    46.  

  12.  
  13. Install the common chamber duct bracket bolts to the rear of the common chamber duct.
  14.  
  15. Install the six bolts and two nuts to the common chamber duct.
  16.  
  17. Install the ground cable fixing bolt to the rear of the common chamber duct.
  18.  
  19. Install the four bolts, four nuts and three manifold bracket bolts to the common chamber duct.
  20.  
  21. Install the exhaust manifold and install the four bolts to the EGR valve assembly and common chamber duct.
  22.  
  23. Connect the evaporative emission canister purge hose to the common chamber duct.
  24.  
  25. Connect the PCV hose to the common chamber duct.
  26.  
  27. Connect the fuel pressure control valve vacuum hose to the common chamber duct.
  28.  
  29. Connect the canister VSV and the EGR VSV vacuum hose to the throttle body.
  30.  
  31. Install the throttle body and install the four bolts to the throttle body and remove the throttle body.
  32.  
  33. Install the electronic ignition assembly and its bracket.
  34.  
  35. Connect the three connectors to the electronic ignition module.
  36.  
  37. Connect the high tension cable to the cylinder head cover clips.
  38.  
  39. Connect the electrical connectors to the Idle Air Control Valve, Throttle Position sensor, Manifold Absolute Pressure sensor, canister VSV, EGR VSV, Intake Air Temperature sensor and VSV.
  40.  
  41. Connect the vacuum booster hose to the common chamber duct.
  42.  
  43. Connect the canister vacuum hose to the Vacuum Switch Valve (VSV).
  44.  
  45. Connect the accelerator pedal cable to the throttle body and cable brackets.
  46.  
  47. Verify that all vacuum hoses, lines, and wiring harnesses are reconnected.
  48.  
  49. Install the air cleaner assembly.
  50.  
  51. Connect the negative battery cable.
  52.  

1996 VEHICLES

See Figures 16, 17, 18, 19, 20 and 21



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Fig. Fig. 16: Linear EGR valve and connections



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Fig. Fig. 17: Intake manifold chamber bolts and bracket locations



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Fig. Fig. 18: Fuel feed and return lines



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Fig. Fig. 19: Apply sealant to the cylinder head at the camshaft holder mounts



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Fig. Fig. 20: Camshaft mounting bolts-tightening sequence



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Fig. Fig. 21: Apply sealant to the camshaft holders

  1. Relieve the fuel system pressure:
    1. Remove the fuel filler cap.
    2.  
    3. Remove the fuel pump relay from the underhood relay box.
    4.  
    5. Start the engine and let it run until it stalls. Then, crank the engine for an additional 30 seconds.
    6.  
    7. Turn the ignition switch to the OFF position.
    8.  

  2.  
  3. Disconnect the negative battery cable and reinstall the fuel pump relay.
  4.  
  5. Drain the coolant into a sealable container.
  6.  
  7. Support the hood as far open as possible.
  8.  
  9. Remove the air intake duct and the air cleaner box.
  10.  
  11. Disconnect and remove the upper and lower radiator hoses. Catch any coolant that runs out.
  12.  
  13. Loosen and remove the power steering pump, A/C compressor, and alternator drive belts.
  14.  
  15. Remove the cooling fan and its pulley assembly.
  16.  
  17. Unbolt the power steering pump mounting bracket. Move the pump and bracket out of the way without disconnecting the hydraulic lines.
  18.  
  19. Disconnect the throttle cable from the throttle body linkage.
  20.  
  21. Label and disconnect the following vacuum hoses from the intake manifold chamber:
    1. PCV hose
    2.  
    3. EVAP canister vacuum hose
    4.  
    5. Brake booster hose
    6.  

  22.  
  23. Label and disconnect the following sensor connectors from the rear of the intake manifold chamber:
    1. Ignition control module connectors
    2.  
    3. Linear EGR valve
    4.  
    5. MAP sensor
    6.  
    7. EVAP purge valve
    8.  
    9. Throttle position sensor
    10.  
    11. Idle air control valve
    12.  
    13. Intake air temperature sensor
    14.  

  24.  
  25. Disconnect the EGR valve supply tube and bracket.
  26.  
  27. First, remove the throttle body, and then remove the intake manifold chamber.
  28.  
  29. Carefully clean any dirt from the fuel rail and fuel fittings.
  30.  


CAUTION
Fuel injection systems remain under pressure even after the engine has been turned off. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and personal injury.

  1. Disconnect the fuel feed and return lines from the front of the fuel rail. Clean up any spilled fuel.
  2.  
  3. Remove the intake manifold gaskets. Be careful not to drop any pieces of the gaskets into the engine. Don't scratch or gouge the machined aluminum mating surfaces of the intake manifold and engine block.
  4.  
  5. Cover the intake openings with a sheet of plastic or clean shop towels to keep out dirt and foreign objects.
  6.  
  7. Label the ignition coil assemblies and disconnect them from the wiring harness. Remove the coil assemblies so they won't be damaged.
  8.  
  9. Unbolt the oil cooler line brackets from the timing belt covers.
  10.  
  11. Remove the upper timing belt covers.
  12.  
  13. Rotate the crankshaft to align the camshaft timing marks with the pointer dots on the back covers. When the timing marks are aligned, the No. 2 piston is at TDC/compression.
  14.  
  15. Remove the crankshaft pulley. Remove the lower timing belt cover.
  16.  
  17. Remove the pusher assembly (tensioner) from below the timing belt tensioner pulley. The pusher rod must always be facing upward to prevent oil leakage. Push the pusher rod in, and insert a wire pin into the hole to keep the pusher rod retracted.
  18.  
  19. Remove the timing belt.
  20.  


WARNING
If the timing belt is worn, damaged, or shows signs of oil or coolant contamination, it must be replaced.

  1. Loosen the valve cover bolts in a crisscross sequence. Remove the valve covers.
  2.  
  3. Remove the camshaft sprockets and back covers.
  4.  
  5. Loosen the camshaft holder bolts in a crisscross sequence to prevent warping.
  6.  
  7. Remove the camshaft and camshaft holders from the cylinder head.
  8.  
  9. Inspect the camshaft lobes and journals for signs of wear or damage.
  10.  
  11. Loosen the exhaust and intake rocker shaft bolts in a crisscross sequence to prevent warping.
  12.  
  13. Remove the intake and exhaust rocker shafts from the cylinder head.
  14.  
  15. If the rocker arms and shafts must be disassembled, label the parts and wave washers so that they can be reassembled in the same positions.
  16.  
  17. If necessary, remove the hydraulic valve lash adjusters from the rocker arms.
  18.  
  19. Inspect the hydraulic lash adjusters for excess movement and replace if necessary. The hydraulic lash adjusters are designed to be self-bleeding, but new adjusters must be primed before installation.
    1. Use a small-diameter rod (0.08 in. or 2mm) to push in the adjuster's check ball.
    2.  
    3. Submerge the adjuster in a tub of clean engine oil.
    4.  
    5. Pump the plunger with your finger to fill the adjuster with oil and displace any air.
    6.  
    7. Keep pumping the plunger until it's hard and no more air bubbles come out. Then, remove the rod to release the check ball.
    8.  

  20.  

To install:
  1. Reassemble the rocker arm, shaft, and hydraulic lash adjuster components. Assemble the hydraulic lash adjusters to the rockers before removing them from the tub of oil. The intake rocker arms all face the same direction when installed.
  2.  
  3. Lubricate the rocker arms and shafts with clean engine oil.
  4.  
  5. Install the intake and exhaust rocker arms and shaft assemblies. Tighten the rocker shaft holder bolts to 13 ft. lbs. (18 Nm), starting with the intake shaft and then moving to the exhaust shaft. Make sure the intake and exhaust rockers contact each other properly.
  6.  
  7. Make sure all mating surfaces are clean and free of oil, coolant, or gasket residue.
  8.  
  9. Lubricate the camshaft lobes and journals with clean engine oil.
  10.  
  11. Apply a bead of sealant to the front and rear camshaft holder mating surfaces on the cylinder head.
  12.  
  13. Install the camshaft and holder assembly onto the cylinder head before the sealant cures. Install the camshaft holder bolts, but don't tighten them yet.
  14.  
  15. Use a crisscross sequence to tighten the camshaft holder bolts. Tighten the 8mm bolts to 13 ft. lbs. (18 Nm). Tighten the 6mm bolts to 6 ft. lbs. (8 Nm).
  16.  
  17. Use a seal driver to install a new camshaft seal.
  18.  
  19. Install the camshaft sprocket back covers and tighten their bolts to 12 ft. lbs. (17 Nm).
  20.  
  21. Install the camshaft sprockets so that the timing marks are aligned. Tighten the bolts to 46 ft. lbs. (64 Nm).
  22.  
  23. Apply a 2-3mm bead of sealant to the joint were the camshaft holders meet the cylinder head. Install the valve cover with a new gasket before the sealant cures.
  24.  
  25. Tighten the valve cover bolts to 6 ft. lbs. (8 Nm) in crisscross pattern.
  26.  
  27. Verify that the camshaft and crankshaft timing marks are properly aligned.
  28.  
  29. Install and tension the timing belt. Tighten the pusher bolts to 14 ft. lbs. (19 Nm).
  30.  
  31. Install the lower timing belt covers and tighten the bolts to 13 ft. lbs. (18 Nm). Install the crankshaft pulley. Tighten the pulley bolt to 123 ft. lbs. (167 Nm).