Valve Spring Squareness

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.

Set try square along the side of valve spring and rotate spring. Measure the maximum clearance between the top face of spring and try square.
Limit: 2.1 mm (0.083 in)

Fig 1: Measuring Clearance Between Top Of Valve Spring Using Try Square
Courtesy of NISSAN NORTH AMERICA, INC.
If it exceeds the limit, replace valve spring.