Cylinder Head Distortion
WARNING: This page is about a different car, the 2018 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
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, below. Refer to Disassembly and Assembly
If it exceeds the limit, replace the cylinder head.
The limit for cylinder head resurfacing is determined by the cylinder block resurfacing. Refer to Cylinder Head
After resurfacing cylinder head, check that camshaft rotates freely by hand. If resistance is felt, cylinder head must be replaced.