Valve Clearance: Adjustment

WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.

Perform adjustment depending on selected head thickness of 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.

Remove camshaft. Refer to REMOVAL AND INSTALLATION .
Remove the valve lifters at the locations that are outside the standard.
Measure the center thickness of the removed valve lifters with a micrometer.

Fig 1: Checking Center Thickness Of Lifter
Courtesy of NISSAN MOTOR CO., U.S.A.
Use the equation below to calculate valve lifter thickness for replacement.
- Valve lifter thickness calculation.
  t=t1 + (C1 - C2)
  
  t=Thickness of replacement valve lifter.
  
  t1=Thickness of removed valve lifter.
  
  C1=Measured valve clearance.
  
  C2=Standard valve clearance.
  - Thickness of a new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder).
    Stamp mark 696 indicates a thickness of 6.96 mm (0.2740 in)
  Available thickness of valve lifter: 26 sizes with a range of 6.96 to 7.46 mm (0.2740 to 0.2937 in), in steps of 0.02 mm (0.0008 in), when assembled at the factory.
Install the selected valve lifter.
Install camshaft.
Manually turn crankshaft pulley a few turns.
Check that valve clearances for cold engine are within specifications, by referring to the specified values.
After completing the repair, check valve clearances again with the specifications for warmed engine. Use a feeler gauge to measure the clearance between the valve and camshaft. Make sure the values are within specifications.
Valve clearance:

Fig 3: Valve Clearance Specifications
Courtesy of NISSAN MOTOR CO., U.S.A.