The vapors push back into the engine and the oil returns to the PCV system for further use. It then redistributes the substances to where they belong in the engine. The Air Oil Separator, or AOS, pulls the oil out of the vapors. If this oil makes it back into your engine, it can cause a harmful build-up and potential improper detonation of the cylinders.Ĭue an Air Oil Separator that operates just how its name indicates. However, these gasses pass through the PCV system of the engine and they pick up traces of oil. Street legal vehicles are not allowed to emit these gasses into the atmosphere, instead, they need to be recirculated back into the engine, which will also relieve pressure in the engine.

Keep reading for a complete guide to buying, installing, and using Air Oil Separators.Īs a car runs, the engine cylinders emit gasses. There are different reasons for getting one and many options on the market.

Air Oil Separators are a smart addition to most vehicles because they help the engine run efficiently and keep it clean under the hood.

Aig air oil separator review