Replacing Valve Seat For Service Parts

WARNING: This page is about a different car, the 2004 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

Bore out old seat until it collapses. Set machine depth stop so that boring cannot contact the bottom face of seat recess in cylinder head.
Ream cylinder head recess. Refer to , "VALVE SEAT " for the reaming bore for the service valve seat.
NOTE: Use the valve guide center for reaming to ensure valve seat will have the correct fit.

Fig 1: Identifying Cylinder Head Recess Diameter
Courtesy of NISSAN MOTOR CO., U.S.A.
Heat cylinder head to 110° to 130°C (230° to 266°F).

Fig 2: Heating Cylinder Head
Courtesy of NISSAN MOTOR CO., U.S.A.
Press fit valve seat until it seats on the bottom.
Cut or grind valve seat using suitable tool to the specified dimensions. Refer to , "VALVE ".
After cutting, lap valve seat with abrasive compound.
Check valve seating condition.
1. Seat face angle "°" : 44°53' - 45°07'
2. Contacting width "W"
  1. Intake : 1.06 - 1.34 mm (0.0417 - 0.0528 in)
  2. Exhaust : 1.34 - 1.63 mm (0.0528 - 0.0642 in)
Fig 3: Identifying Valve Seat Face Angle And Contacting Width
Courtesy of NISSAN MOTOR CO., U.S.A.
Use a depth gauge to measure the distance "L" between the mounting surface of the cylinder head spring seat and the valve stem end. If the distance is shorter than specified, repeat step 5 above to correct it. If the distance is longer, replace the valve seat.
1. Valve seat resurface limit
  1. Intake : 35.95 - 36.55 mm (1.4154 - 1.4390 in)
  2. Exhaust : 35.92 - 36.52 mm (1.4142 - 1.4378 in)
Fig 4: Identifying Distance Between Mounting Surface Of Cylinder Head Spring Seat And Valve Stem End
Courtesy of NISSAN MOTOR CO., U.S.A.