This paper presents the development of a Plastic Valve Cover System (PVCS) using Finite Element Analysis (FEA). This approach results in a shorter development period and reduced costs. The numerical methodology is divided into two steps. First, a two-dimensional analysis is of the rubber components (gasket, grommet) determines the load-deflection response and the system equilibrium for the complete range of component tolerances. These curves are utilized in a second step. Applied to a three-dimensional model of the cover, the analysis determines the valve cover optimal design. The paper describes other relevant issues related to PVCS's such as: a) influence of strain damage on elastomeric response. b) element type, size and order selection for optimum modeling. Comparisons with experimental results are presented and the appropriate conclusions are drawn.