Inspection After Removal

WARNING: This page is about a different car, the 2012 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

Cylinder Head Bolts Outer Diameter

Cylinder head bolts are tightened by plastic zone tightening method. Whenever the size difference between "d1" and "d2" exceeds the limit, replace the bolt with a new one.
Limit ("d1"-"d2"): 0.11 mm (0.0043 in)

Fig 1: Identifying Cylinder Head Bolts Diameter
Courtesy of NISSAN NORTH AMERICA, INC.
If reduction of outer diameter appears in a position other than "d2", use it as "d2" point.

Cylinder Head Distortion

NOTE: When performing this inspection, cylinder block distortion should be also checked. Refer to "INSPECTION AFTER DISASSEMBLY ".

Using suitable tool, wipe off oil, scale, gasket, sealant and carbon deposits from surface of cylinder head.
CAUTION: Do not allow gasket fragments to enter engine oil or engine coolant passages.
At each of several locations on bottom surface of cylinder head, measure the distortion in six directions.
Limit: 0.1 mm (0.004 in)
- Replace cylinder head If measured distortion exceeds the limit.
  
  Fig 2: Measuring Cylinder Head Distortion
  Courtesy of NISSAN NORTH AMERICA, INC.