Valve Spring Dimensions And Valve Spring Pressure Load
WARNING: This page is about a different car, the 2008 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
Check valve spring pressure at specified spring height.
Standard: 166 - 188 N (16.9 - 19.2 kg, 37.3 - 42.3 lb) at height 37.0 mm (1.457 in)
Limit: 373 - 421 N (38.0 - 42.9 kg, 83.9 - 95.0 lb) at height 27.2 mm (1.071 in)
If it is not within specifications, replace the spring.