Valve Guide Clearance

WARNING: This page is about a different car, the 2008 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

Measure valve deflection as shown. (Valve and valve guide mostly wear in this direction.)
Valve deflection limit (dial gauge reading)

Intake: 0.24 mm (0.0094 in)

Exhaust: 0.28 mm (0.0110 in)

Fig 1: Checking Valve Deflection
Courtesy of NISSAN MOTOR CO., U.S.A.
If it exceeds the limit, check valve to valve guide clearance.
1. Measure valve stem diameter and valve guide inner diameter.
2. Check that clearance is within specification.
  Valve to valve guide clearance standard
  
  Intake: 0.020 - 0.053 mm (0.0008 - 0.0021 in)
  
  Exhaust: 0.040 - 0.073 mm (0.0016 - 0.0029 in)
  
  Valve to valve guide clearance limit
  
  Intake: 0.08 mm (0.0031 in)
  
  Exhaust: 0.1 mm (0.004 in)
  
  Fig 2: Measuring Diameter Of Valve Stem With Micrometer
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. If it exceeds the limit, replace valve or valve guide.