Valve Spring Dimensions And Valve Spring Pressure Load

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.

Check the valve spring pressure at the specified spring height.
Standard: Intake and exhaust Free height: 50.58 mm (1.9913 in)

Installation height: 37.0 mm (1.457 in)

Installation pressure: 165.8 - 187.0 N (16.9 - 19.1 kg, 37-42 lb)

Height during valve open: 28.2 mm (1.110 in)

Load with valve open: 314.8 - 355.0 N (32.1 - 36.2 kg, 71 - 80 lb)

Fig 1: Checking Valve Spring Pressure Load At Specified Spring Height
Courtesy of NISSAN NORTH AMERICA, INC.
If measurement is not within specifications, replace the valve spring.