Valve Guide Clearance

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

Measure valve deflection as shown in Fig 1. (Valve and valve guide wear the most in this direction.)
Valve deflection limit (Dial gauge reading)

Intake & Exhaust: 0.2 mm (0.008 in)

Fig 1: Measuring 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.
  
  Fig 2: Measuring Valve Stem Diameter & Valve Guide Inner Diameter
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Clearance Specifications
  Courtesy of NISSAN MOTOR CO., U.S.A.
2. Calculate valve to valve guide clearance.
  Valve stem to valve guide clearance = valve guide inner diameter - valve stem diameter.
3. Check that clearance is within specification.
  - If it exceeds the limit, replace valve and remeasure clearance.
  - If limit is still exceeded after replacing valve, replace valve guide.