Cylinder Head Distortion

Clean the surface of the cylinder head. Use a reliable straightedge and feeler gauge to check the flatness of cylinder head surface.

Check along six positions as shown.

1. Head surface flatness : Limit 0.1 mm (0.004 in) 

If beyond the specified limit, resurface or replace it.

The limit for cylinder head resurfacing is determined by the cylinder block resurfacing. 

1. Resurfacing Limit 
2. Amount of cylinder head resurfacing is "A". 
3. Amount of cylinder block resurfacing is "B". 
4. The maximum limit : A + B = 0.2 mm (0.008 in) 

Fig 1: Checking For Warpage

Courtesy of NISSAN MOTOR CO., U.S.A.

After resurfacing cylinder head, check that camshaft rotates freely by hand. If resistance is felt, cylinder head must be replaced.

1. Nominal cylinder head height : 126.3 - 126.5 mm (4.972 - 4.980 in)