One of the globally challenging issues today is Waste Utilization. The excessive accumulation of waste has created an uncomfortable pressure on not, just the habitant but on the environment as well. As a small step forward in contributing towards minimizing waste disposal, this study attempts to address the problem raised due to the disposal of waste cooking oil. Researchers found that Waste Cooking Oil (WCO) has a very good potential as a fuel for compression ignition engine and was therefore selected for this study. In the first phase of the work, behaviour 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 (TBC) and engine behaviour 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 showed marked improvement 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 emissions were drastically reduced at the cost of increased oxides of nitrogen emissions. It was also found from the analysis that the surface temperature of the coated surface was higher than that of the uncoated surface. 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.