High frequency vibrations (from 200 Hz to 1 kHz) generated by passenger car shock absorbers are not suitable for acoustic comfort reasons. Spring valve dynamics seem to be one of the main reasons of these vibrations because they appear when the spring valve opens or closes. In order to understand the experimental observations and to study the fluid-structure interactions, a phenomenological model close to the shock absorber model was built. The analysis of stability of the system is studied via analytic linearization of the system around an equilibrium position defined by a flow rate. Also, the influence of various parameters on stability and oscillation frequency is studied. These parameters are spring valve preload, valve damping value, constant orifice section and fluid compressibility. The results obtained from this study are compared to experimental observations on a shock absorber tested on a test-rig and show good agreement.