The function of the air intake system is to allow air to reach your car engine. Oxygen in the air is one of the necessary ingredients for the engine combustion process. A good air intake system allows for clean and continuous airflow into the engine, thereby achieving more power and better mileage for your car.
A modern car air intake system has three main parts - the air filter, mass flow sensor and throttle body. Located directly behind the front grille, the air intake system draws air through a long plastic tube going into the air filter housing, which will be mixed with the car fuel. Only then will the air be sent to the intake manifold that supplies the fuel/air mixture to the engine cylinders.
Air Filter: An air filter is an important part of a car's intake system, because it is through the air filter that the engine 'breathes'. It is usually a plastic or metal box in which the air filter sits.
An engine requires an exact mixture of fuel and air in order to run, and all of the air enters the system first through the air filter. The air filter's job is to filter out dirt and other foreign particles in the air, preventing them from entering the system and possibly damaging the engine.
The air filter is usually located in the air stream to your throttle valve assembly and intake manifold. It is found in a compartment in an air duct to the throttle valve assembly under the hood of your car.
Mass flow sensor: A mass air flow sensor is used to find out the mass of air entering a fuel-injected internal combustion engine. From mass flow sensor, then, does it goes to the throttle body.
There are two common types of mass airflow sensors in use on automotive engines. They are the vane meter and the hot wire.
The vane type has a flap that is pushed by the incoming air. The more air coming in, the more the flap is pushed backed. There is also a second vane behind the main one that fits into a closed camber that dampens the movement of the vane giving a more accurate measurement.
The hot wire uses a series of wires strung in the air stream. The electrical resistance of the wire increases as the wire's temperature increases, which limits electrical current flowing through the circuit. When air flows past the wire, it cools, decreasing its resistance, which in turn allows more current to flow through the circuit.
Throttle Body: The throttle body is the part of the air intake system that controls the amount of air flowing into an engine's combustion chamber. It consists of a bored housing that contains a throttle plate that rotates on a shaft.
When the accelerator is depressed, the throttle plate opens and allows air into the engine. When the accelerator is released, the throttle plate closes and effectively chokes-off air flow into the combustion chamber. This process effectively controls the rate of combustion and ultimately the speed of the vehicle. The throttle body is usually located between the air filter box and the intake manifold, and it is usually located near the mass airflow sensor.
