When you should change engine air filter earlier than recommended

When you should change engine air filter earlier than recommended

The engine air filter is one preventive maintenance item that is often overlooked. There are two air filters in a typical car; the engine air filter and the cabin air filter. In this article, we are going to be focusing on the engine air filter.

The engine air filter is responsible for filtering the intake air to prevent dust and other debris from gaining access to the engine.

In environments where the presence of dust is minimal, users skip air filter replacement without any adverse effect. Sometimes, they simply blow away the dust that has accumulated on the filter using compressed air. This should not be a regular practice though because at a point, the air filter should still need replacement.

In environments that are very dusty, it is beneficial to replace the air filter earlier than the time recommended by the car manufacturer. This is because the dust particles concentrates easily on the filter surface, quickly causing the engine air starvation.

When the engine suffers air starvation due to dirty air filter, the following are the effects:

Increased fuel consumption - This happens because the intake air and fuel are stoichiometrically mixed, for instance, 14.7:1 air/fuel ratio. It is this mixture that is compressed, ignited and burned in the combustion chamber to produce power. When the amount of air in relation to fuel is not enough, the mixture becomes rich. That is, the mixture has more fuel than necessary. This increases the car's fuel consumption.

Loss of power - The engine needs both air and fuel to make power. When the intake air is not sufficient, the engine looses power under lean running condition or the Engine Control Unit automatically reduces injector pulse widths to maintain air/fuel stoichiometry. This causes reduction in power output.

Also, when the air filter becomes very dirty and clogged, increase in vacuum forces some dust particles into the combustion chamber and this can cause wear in the piston and cylinder wall.

Again, a clogged or bad filter that allows dust to get into the engine also degrades the engine oil earlier than expected. 

It is advisable to stick with using quality air filters for good engine performance and engine protection. Also, the correct size and fit of air filter should be used to ensure that no part of the intake air escapes unfiltered. Torn air filters should also be replaced immediately.