Air filter (air intake noise damper)

In order to extend the life of the engine, the intake air - before it combines with the fuel into a flammable mixture - passes through a special filter element. It cleans the intake air of dirt and dust particles and is located in the air filter housing (intake air damper) under the hood in the engine compartment on the left in front in the direction of travel.

The intake air damper is not an accidental built-in box that protects the filter element, it must play another important role in the intake path: it «disciplines» intake air, creating a pulsating gas column, and at the same time minimizing suction noise. The Focus's intake noise damper consists of a plastic housing and a finely porous, accordion-folded paper filter insert.

Air filter insert requires constant maintenance

The intake air flows through the air filter housing from the outside to the inside. filter insert (filter element) inside, two synthetic rings are sealed from the side of the suction tract. Accordingly, the entire flow of fresh air on its way to the engine must pass through the filter insert, while the wear-inducing dirt particles remain in the filter paper. Larger foreign bodies, such as insects or grains of sand raised on the road, remain in the filter housing. Of course, the air filter and filter element can only do their job if they are checked regularly. A dirty filter insert prevents air from entering the engine. Consequence: the air-fuel mixture is out of balance, engine power is reduced and fuel consumption increases.