Valve Seats

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.

Check valve seats for pitting at contact surface. Resurface or replace if excessively worn.

Before repairing valve seats, check valve and valve guide for wear. If they have worn, replace them. Then correct valve seat.
Use both hands to cut uniformly.

Fig 1: Cutting Valve Seats
Courtesy of NISSAN MOTOR CO., U.S.A.