By reducing overall noise emanating from Engine at design phase, permits to reduce both time-to-market and the cost for developing new engines. In order to reduce vibration and radiated noise in engine assembly, oil pan is one of the most critical components. This study explains the key-steps that are executed to optimize the oil pan design for 4-cylinder diesel engine by improving Normal Modes, modified Topology, reduced Forced Frequency Response and ATV analysis for reducing its noise radiation.Using Multi-body tool crankshaft forces were generated and the FE model of Base Design was analysed for its noise radiation and panel contribution was done for finding the most radiating panels using Boundary Element Method approach. A series of iterative optimization were carried out with commercial software. Parameters like Stiffness, material property, Ribbing patterns and Shape of the Oil pan was modified to shift the natural frequencies of the component and reduce the sound radiation.Subsequently, the article is concluded by results comparison of baseline design over optimized Vibro-Acoustic results which was obtained from Boundary Element Method showing 5-6 dB(A) reduction in 1meter Engine Noise. The presented methodology proves to help the designers with the definition of a design that reaches the requested Noise and Vibration targets, weight-cost targets along with the manufacturability constrains.