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Valve Clearance: Adjustment

WARNING: This page is about a different car, the 2005 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
  • Perform adjustment depending on the selected head thickness of the valve lifter.
  • The specified valve lifter thickness is the dimension at normal temperatures. Ignore dimensional differences caused by temperature. Use the specifications for hot engine condition to adjust.
  1. Remove the camshaft. Refer to "REMOVAL AND INSTALLATION ".
  2. Remove the valve lifters at the locations that are out of specification.
  3. Measure the center thickness of the removed valve lifters using suitable tool.
    Fig 1: Measuring Center Thickness Of Removed Valve Lifters Using Suitable Tool
    G02384501Courtesy of NISSAN MOTOR CO., U.S.A.
  4. Use the equation below to calculate the valve lifter thickness for replacement.
    • Valve lifter thickness calculation:

      Thickness of replacement valve lifter = t1+ (C1 - C2)

      t1 = Thickness of removed valve lifter

      C1 = Measured valve clearance

      C2= Standard valve clearance:

      1. Intake: 0.36 mm (0.0142 in)* 
      2. Exhaust: 0.37 mm (0.0146 in)* 
      3. *: Approximately 80°C (176°F) 
    • Thickness of a new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder). Stamp mark N788 indicates 7.88 mm (0.3102 in) in thickness.
    • Available thickness of valve lifter: 25 sizes with range 7.88 to 8.36 mm (0.3102 to 0.3291 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to "AVAILABLE VALVE LIFTER ".
    Fig 2: Determining Thickness Of Valve Lifter Using Stamp Marks
    G02384502Courtesy of NISSAN MOTOR CO., U.S.A.
  5. Install the selected valve lifter.
  6. Install the camshaft.
  7. Manually turn the crankshaft pulley a few turns.
  8. Make sure the valve clearances for cold engine are within specifications by referring to the specified values.
  9. After completing the repair, check the valve clearances again with the specifications for a warmed engine. Make sure the values are within specifications.
    1. Valve clearance standard: 
      1. Hot* 
        1. Intake: 0.304 - 0.416 mm (0.012 - 0.016 in) 
        2. Exhaust: 0.308 - 0.432 mm (0.012 - 0.017 in) 
      2. Cold 
        1. Intake: 0.26 - 0.34 mm (0.010 - 0.013 in) 
        2. Exhaust: 0.29 - 0.37 mm (0.011 - 0.015 in) 
    2. *: Approximately 80°C (176°F) 
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