The intake air noise damper is not a coincidence that it is a built-in box protecting the filter element, it must perform another important role in the intake tract: it "disciplines" the intake air, creating a pulsating column of gas, and at the same time minimizes intake noise. The intake air noise damper in the Focus consists of a plastic housing and a fine-pored, accordion-folded paper filter insert.
The air filter insert requires regular maintenance
The air sucked in passes through the air filter housing from the outside to the inside. The filter insert (filter element) is sealed inside by two synthetic rings on the suction side. Accordingly, the entire flow of fresh air on its way to the engine must pass through the filter insert, while the dirt particles that cause wear 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 does not allow air to pass into the engine. Consequence: the fuel-air mixture loses its balance, engine power decreases and fuel consumption increases.