The Automotive industry is constantly facing new challenges as the demand for light weight, inexpensive but high quality components is increasing. New failure modes need to be searched to avoid any failure in all conditions prevalent in market. The present work gives an approach to predict possible failure for durability in engine mount bolt in passenger vehicles . Engine Mount integrates powertrain with rubber insulator at chassis side. Its pivotal role is to support powertrain and to isolate engine vibrations throughout life-cycle of the vehicle. Supporting powertrain in dynamic condition creates an inherent demand of strength from engine mounting system. The dynamic load acting on engine mount is due to engine combustion and inertia forces and road loads during running condition. This paper emphasizes on a particular load-case experienced while vehicle is being tested for durability on rough road. Applied load location on engine mount bracket is generally at an offset from the bolt. The offset creates a bending moment on the bolt. Alternate bending moment during durability test generates micron opening in the contact face. The contact opening(C-OPEN) is simulated by FEM method. Higher contact opening reduces bolt's axial tension. And eventually the bolt may fail in shear. The failure mode has been simulated in test-bench set up. Test set-up can almost precisely predict at what cycle the mounting bolt failure will occur at actual vehicle durability test. A technical approach is presented to design and validate engine mount bolt supported by an engineering concept with stress measurement, bolt axial force measurement and finite element method (FEM) analysis.