Automobile engine seals are made of elastomeric materials and used to seal the interfaces between engine exterior covers and underlying structures. The design of engine seals has been traditionally focused on the sealability aspect. There has been increased demand that these seals be designed as vibration isolators as well to attenuate the radiated noise from the engine. This paper presents a design methodology to balance the sealing and NVH performance of the engine cover systems. Elastomer-isolated cylinder-head cover assembly is used as an example. The use of finite element method to design the sealability and NVH of the engine cover systems will be presented.