Infinity_QX4_1998-2003

Timing Chain & Sprockets

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Removal & Installation



3.5L Engine
  1. Release fuel pressure.
  2.  
  3. Remove the battery.
  4.  
  5. Remove the radiator.
  6.  
  7. Drain engine oil.
  8.  
  9. Remove the drive belts and idler pulley with brackets.
  10.  
  11. Remove the cooling fan with bracket.
  12.  
  13. Remove the engine cover.

    Click image to see an enlarged view

    Fig. Rear timing case removal sequence-3.5L engine

  14.  
  15. Remove the air duct with air cleaner case, collector, blow-by hose, vacuum hoses, fuel hoses, water hoses, wires, harnesses, connectors and so on.
  16.  
  17. Remove the air compressor, and tie it down using rope or the like to keep it from interfering.
  18.  
  19. Remove the power steering oil pump and reservoir tank. Tie them down using rope or the like to keep them from interfering.
  20.  
  21. Remove the alternator.
  22.  
  23. Remove the following.

    Vacuum gallery
     
    Water bypass pipe
     
    Brackets

    Click image to see an enlarged view

    Fig. Primary and secondary sprockets-3.5L engine

     

  24.  
  25. Remove the camshaft position sensor (PHASE), intake valve timing control position sensors and crankshaft position sensor.
    NOTE
    Avoid impact such as dropping. Do not disassemble the components. Do not place them on areas where iron powder may adhere. Keep away from the objects susceptible to magnetism.

  26.  
  27. Remove the upper intake manifold collector in reverse order of installation.
  28.  
  29. Remove the intake manifold collector support bolts.
  30.  
  31. Remove the lower intake manifold collector in reverse order of installation.
  32.  
  33. Disconnect injector harness connectors.
  34.  
  35. Remove the fuel tube assembly in reverse order of installation.
  36.  
  37. Remove the ignition coils.
  38.  
  39. Remove the RH and LH rocker covers from cylinder head.
  40.  
  41. Set No. 1 piston at TDC on the compression stroke by rotating crankshaft. Align pointer with TDC mark on crankshaft pulley. Check that intake and exhaust cam nose on No. 1 cylinder are installed as shown left. If not, turn the crankshaft one revolution (360°) and align as above.
  42.  
  43. Remove the starter motor, and set ring gear stopper using the mounting bolt hole. Be careful not to damage the signal plate teeth.
  44.  
  45. Loosen the crankshaft pulley bolt.
  46.  
  47. Remove the crankshaft pulley with a suitable puller.
  48.  
  49. Remove the aluminum oil pan.
  50.  
  51. Temporarily install the suspension member bolts and engine mounting nuts.
  52.  
  53. Remove the intake valve timing control valve covers. Loosen bolts in numerical order as shown in the figure. In the cover, the shaft is engaged with the center hole of the intake cam sprocket. Remove it straight out until the engagement comes off.
  54.  
  55. Remove the front timing chain case bolts. Loosen bolts in numerical order as shown in the figure.
  56.  
  57. Remove the front timing chain case. Do not scratch sealing surfaces.
  58.  
  59. Remove the internal chain guide.
  60.  
  61. Remove the upper tension guide.
  62.  
  63. Remove the timing chain tensioner and slack guide. Remove timing chain tensioner. (Push piston and insert a suitable pin into pinhole.)
  64.  
  65. Attach a suitable stopper pin to RH and LH camshaft chain tensioners.
  66.  
  67. Remove the intake and exhaust camshaft sprocket bolts. I Apply paint to timing chain and camshaft sprockets for alignment during installation. Secure the hexagonal head of the camshaft using a spanner to loosen mounting bolts.
  68.  
  69. Remove the primary and secondary timing chains along with the camshaft sprockets. Do not disassemble the intake camshaft sprocket. Avoid damaging the signal mark protrusion area at the front of the left bank intake camshaft sprocket. Keep it away from magnetized objects.
  70.  
  71. Remove the lower chain guide.
  72.  
  73. Remove the crankshaft sprocket.
  74.  
  75. Use a scraper to remove all traces of liquid gasket from front timing chain case. Remove old liquid gasket from the bolt hole and thread.
  76.  
  77. Use a scraper to remove all traces of liquid gasket from intake valve timing control valve cover.

    Click image to see an enlarged view

    Fig. Timing chain components-3.5L engine

  78.  

To install:

  1. Position crankshaft so that No. 1 piston is set at TDC on compression stroke.
  2.  
  3. Install crankshaft sprocket on crankshaft. Make sure that mating marks on crankshaft sprocket face front of engine.
  4.  
  5. Install lower chain guide on dowel pin, with front mark on the guide facing upside.
  6.  
  7. Press and shrink the secondary chain tensioner sleeve, and fix it using stopper pins. Lubricate threads and seat surfaces of camshaft sprocket bolts with new engine oil.
  8.  
  9. Install secondary timing chain and sprocket to one of the banks (Right bank shown in the figure) as described below.

    Click image to see an enlarged view

    Fig. Secondary timing chain installed-3.5L engine

    1. Align mating marks (golden links) on secondary timing chain with those (punched marks) on the intake and exhaust sprockets.
    2.  
    3. Align camshaft knock pins with the sprocket groove and hole. Because camshaft sprocket mounting bolts are tightened in step 7, perform manual tightening to the extent necessary to keep camshaft knock pin from dislocating. Matching marks of the intake sprocket are on the back side of the secondary sprockets. There are two types of the marks; round and oval types, which should be used for right and left banks respectively.

      Click image to see an enlarged view

      Fig. Intake sprocket mating marks-3.5L engine



      Right bank: Round
       
      Left bank: Oval
       

    4.  

  10.  

It may be difficult to visually check the dislocation of mating marks during and after installation. To make the matching easier, make a mating mark on the sprocket teeth in advance using paint.

  1. Install secondary timing chain and sprocket to the other bank. Install primary timing chain at the same time. Installation of the secondary timing chain follows the procedure described in step 5.

    Click image to see an enlarged view

    Fig. Primary timing chain installation-3.5L engine

  2.  
  3. Install primary timing chain so that mating mark (punched) on camshaft sprocket is aligned with that (dark blue link) on the timing chain, and mating mark (notched) on crankshaft sprocket is aligned with that on the timing chain, respectively.
  4.  
  5. When it is difficult to align mating marks of the primary timing chain with each sprocket, gradually turn the camshaft hexagonal head using a spanner so it is aligned with the mating mark.
  6.  
  7. During alignment, be careful to prevent dislocation of mating marks on the secondary timing chain.
  8.  
  9. After confirming the mating marks are aligned, tighten the camshaft sprocket mounting bolts. Secure the camshaft hexagonal head using a spanner to tighten mounting bolts.
  10.  
  11. Pull out the stopper pin from the secondary timing chain tensioner.
  12.  
  13. Install internal guide.
  14.  
  15. Install upper tension guide and slack guide.
  16.  
  17. Install timing chain tensioner, then remove the stopper pin. When installing the timing chain tensioner, engine oil should be applied to the oil hole and tensioner.
  18.  
  19. Install O-rings on rear timing chain case.
  20.  
  21. Apply liquid gasket to front timing chain case. Before installation, wipe off the protruding sealant.
  22.  
  23. Install rear case pin into dowel pin hole on front timing chain case.

    Click image to see an enlarged view

    Fig. Rear timing case installation-3.5L engine

  24.  
  25. Tighten bolts to the specified torque in order shown in the figure. Leave the bolts unattended for 30 minutes or more after tightening.
  26.  
  27. Install intake valve timing control valve cover.
    1. Install O-rings at front timing chain case.
    2.  
    3. Install seal ring at intake valve timing control valve covers.
    4.  
    5. Apply liquid gasket to intake valve timing control valve covers. Use RTV silicone sealant or equivalent. I Being careful not to move the seal ring from the installation groove, align the dowel pins on the chain case with the holes to install the intake valve timing control valve cover. Tighten in numerical order as shown in the figure.

      Click image to see an enlarged view

      Fig. Right rocker cover installation-3.5L engine



      Click image to see an enlarged view

      Fig. Left rocker cover installation-3.5L engine

    6.  

  28.  
  29. Install RH and LH rocker covers. Rocker cover tightening procedure:

    Tighten in numerical order as shown in the figure.
     
    Tighten bolts 1 to 10 in that order to 61 - 78 inch lbs. (7 - 9 Nm).
     
    Then tighten bolts 1 to 10 as indicated in figure to 61 - 78 inch lbs. (7 - 9 Nm).
     

  30.  
  31. Hang engine using the right and left side engine slingers with a suitable hoist.
  32.  
  33. Set a suitable transmission jack under the suspension member.
  34.  
  35. Remove the right and left side engine mounting nuts.
  36.  
  37. Remove the right and left side suspension member bolts.
  38.  
  39. Install aluminum oil pan.
  40.  
  41. Set ring gear stopper using the mounting bolt hole. Be careful not to damage the signal plate teeth.
  42.  
  43. Install crankshaft pulley to crankshaft. Align pointer with TDC mark on crankshaft pulley.
  44.  
  45. Install crankshaft pulley bolt. Lubricate thread and seat surface of the bolt with new engine oil. Tighten to 29 - 36 ft. lbs. (39 - 49 Nm). Put a paint mark on the crankshaft pulley. Again tighten by turning 60° to 66°, about the angle from one hexagon bolt head corner to another.
  46.  
  47. Install camshaft position sensor (PHASE), crankshaft position sensors (REF)/(POS) and intake valve timing control position sensors.
  48.  
  49. Reinstall removed parts in the reverse order of removal. After starting engine, keep idling for three minutes. Then rev engine up to 3,000 rpm under no load to purge air from the high-pressure chamber of the chain tensioners. The engine may produce a rattling noise. This indicates that air still remains in the chamber and is not a matter of concern.
  50.  

 
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