The performance of engine cooling system is influenced by various factors which are bumper, opening area of grill, radiator, condenser, cooling fan etc. To optimize the engine cooling system is important as well as improvement of component of engine cooling module. To predict performance of engine cooling system using the 1D simulation code is very helpful at early development stage because the simulation can reduce the time and cost of test. This study focuses on prediction of performance of engine cooling system using the 1D simulation code and optimization of engine cooling module using the Taguchi method.