Why Intercooler Is Used In Diesel Engine. In a diesel engine air and the fuel are infused into the engine at different stages as opposed to a gas engine where a mixture of air and gas are introduced. The hot air from the turbo enters at one end and as cooled as it passes through the intercooler much like the water in a cars radiator before entering the engine.

An intercooler is a mechanical device used to cool a gas after compression. A cold-air intake on the other hand is designed to replace the hot humid outside air entering your engine with cooler denser inside air. An intercooler typically takes the form of a heat exchanger that removes waste heat in a gas compressor.
The intercoolers job is to cool the compressed heated air charge before it enters the engines combustion chamber.
When the air temperature is low it make the air molecules smaller so that the air will be more dense with more mass in the combustion chamber. Unfortunately as air gets hotter it also becomes less dense reducing the amount of oxygen available in each cylinder and impacting on performance. An intercooler is usually used in turbocharged engines to provide cooling to compressed air before it enters the engine circulation. Well my instructor wants to know why in the world is my intercooler full of oil and how and why the oil is getting there.

