The paper presents results of the three dimensional finite element study conducted to estimate the blowby from multi-cylinder diesel engine using finite element approach. The CAD model of the engine is modeled using UG-Nx-3 modeling software, and the required finite element mesh is obtained by using HYPERMESH preprocessor. The model is made to mimic the working conditions in the engine by applying appropriate boundary conditions. The effect of hydrodynamic lubrication at piston skirt is imposed by solving Reynolds equation to use in F.E.Model. The complete model is simulated by using L.S.Dyna software. The results of simulation are used to estimate the blowby losses from the engine. It is found that the major flow of gasses take place through the end gap of the rings. The blowby results obtained from the model are having good correlation with the experimentally measured values.