DriverSide's Car Dictionary has the most comprehensive definitions of automotive terms. This auto glossary can help you decipher what your mechanic is fixing and what the purpose or function of the particular auto part or accessory is for. We have taken the mystery out of automotive service jargon, so that you don't have to.
You car has two primary types of valves--Inlet and Exhaust--the act as little "doors" to hold air in and let air out, depending on the need. The exhaust valve opens to allow the spent combustion gases to exit the combustion chamber.