Waste Utilization is consider as one of the challenge task all around the globe, as it creates uncomfortness to the habitant as well as the environment. As an initiative of the above problem a small step was taken in this work to address the problem raised on the disposal of waste cooking oil. Researchers found that Waste Cooking Oil (WCO) has a very good potential to use as a fuel for compression ignition engine. In view of above points an attempt was made in coming across the suitable methods of using WCO as fuel. In the first phase of the work behavior of the test engine was studied with neat WCO at different power outputs. As the first modification, neat WCO was converted in to its methyl ester and tested in the same engine. Next, combustion chamber parts like piston and cylinder head, inlet and exhaust valves were coated with thermal barrier coating and engine behavior was studied. To make the study more interesting a thermal- stress analysis was done on the engine piston to examine the impact of coating on engine performance. Results claimed that Brake Thermal Efficiency (BTE) of the engine operated with methyl esters of WCO was on the improved side as compared to its neat form. However the smoke emission was found to be still on the higher range with methyl ester of WCO. Engine results with thermal barrier coating reported improved BTE as compared to the earlier case. Interestingly all the carbon based emission were drastically reduced at the cost of increased oxides of nitrogen emissions. It is also found from the analysis that the temperature of the coated surface is higher than that of uncoated. Thus this work concludes that WCO in the form of its methyl ester can be used effectively in the compression ignition engine with a slight modification of the combustion chamber parts.