The objective of the present work is to study the temperature and heat flux variation with the variation in the thickness of plasma sprayed ceramic coating on an aluminium alloy piston crown by finite element method using ANSYS. Piston is first designed in Solid Works and then imported to ANSYS wherein temperature and heat flux analysis of different thicknesses are done. Ceramic thickness being considered for analysis are 0.3mm, 0.5mm, 0.7mm, 0.9mm, 1.1mm and 2mm. This showed that with increasing thickness, temperatures on top coating of MgZrO3 increased and the same on bottom most layer of the Aluminium alloy engine decreased. The higher temperatures on top coating led to lower temperatures on the top layer of the piston. This is helpful to increase the life of the piston as it helps to prevent development of thermal stresses. Comparison of the same has been done with an engine piston without any ceramic coatings. Heat flux is also analysed in order to critically understand the extent of heat energy that penetrates the surface of the piston. The analysis shows that greater the coating thickness, lesser is the extent of heat flux into the piston which also helps in increasing the life span. For the purpose of this paper the model of a diesel engine piston and magnesia-stabilized zirconia as ceramic coating are considered. © IAEME Publication.