Filters are necessary car components if you want everything to run smoothly. They remove contaminants and impurities in the air, oil, and fuel circulating in different parts of the car. If faulty or clogged, they can cause several issues and lead to complete engine failure. That’s why a timely replacement is a must.
What Are Car Air Filters?
Air filters are devices that remove contaminants in the air. They consist of a filtering medium that lets air pass but prevents the passage of solid and potentially dangerous particles.
Most vehicles come with two types: cabin and engine filters. The first removes impurities in the air circulating in the car’s air-conditioning system, and the second retains dust, dirt, and other particles before the air is pushed in for combustion.
The two types work in slightly different ways. The cabin type uses activated carbon or charcoal to capture impurities in addition to a pleated filtering medium, and the combination is good at nulling nasty odors and toxic gases.
Those used in the engine bay have pleated paper to prevent harmful substances from reaching the cylinders, which can cause loss of power in subtle cases or damage in others. Engine varieties come in different shapes and sizes and are usually located in a boxy housing at the front of the engine and just before the throttle body.
The Basics of Air Filtering
While low-tech, this part has the task to eliminate anything affecting air purity. It largely depends on the design and how porous the filtering medium is. The aim is to provide enough air while keeping harmful particles and substances at bay.
For the engine, you’ll want auto air filters that are neither too restrictive to cut optimal airflow and impact performance and fuel consumption nor too permissive in that larger particles pass through and potentially cause damage. On the other hand, cabin types are more restrictive since they need to purify the cabin air and that which is cooled by the AC from smells and allergens.
Filters work optimally when new. However, over time they will get dirty to the point that clogged particles inside block the air. Cleaning is one way to prolong its life, either with a cleaning solution or simple vacuuming. But at some stage, you’ll need a replacement.
Since auto air filters are cheap, relatively quick, and easy to replace without tools, they should be swapped out regularly. Generally, engine filters are replaced every 12 to 15 thousand miles, depending on the model and the engine. Cabin types last a bit longer, and are swapped out around 30 thousand miles, or roughly every two years.
Shopping is made simple, with both manufacturers and retailers selling the right filters online and in-store for your make, model, and production year.
Filter Types
Engine filters can be grouped by filtering media into three major types: paper, foam, and cotton gauze filters. Paper types are made from special paper derived from compacted wood pulp. To maximize efficiency and increase the filtering area, the paper is pressed into pleats.
Overall, these are the most common types of car air filters found today and are used in passenger vehicles, trucks, and heavy machinery. They are easy and cheap to produce, easy to maintain and clean, and highly effective at what they do.
Foam varieties use polyurethane to keep contaminants out. They are generally more practical in capturing larger particles but allow for high air flow rates, so are often seen in off-roading vehicles and some racing applications. They’re also a bit more expensive since most types are washable and can be used more than once.
Cotton gauze filters consist of cotton intertwined by a thin aluminum mesh. The advantage of this design is that these too are reusable and last the longest. The are two types: oiled and synthetic dry gauze filters. Oiled versions, in particular, need the least maintenance and are the easiest to clean. The downside, though is that they are less restrictive, so won’t filter out larger particles.
Signs of Faulty Filters
Filters are regularly replaced for a reason. They get clogged, and their purifying ability reduces over time. This can lead to many unwanted issues. The most common are:
- Poor performance – dirty and clogged filters limit the amount of clean air that reaches the engine. This directly impacts performance and is something that is more noticeable with half-hearted acceleration, even with your foot firmly on the gas. Related issues are hard starts, rough idling, and misfires, all as a result of changed air-to-fuel ratios and rich fuel mixtures. This leads to major issues, such as black exhaust smoke and soot buildup on spark plugs. Cleaning the filter or using a replacement should resolve most issues.
- Reduced Fuel Economy – less air means more fuel. If you notice that your car is using more fuel than usual, a probable sign is that the filter needs replacing.
- Gas Smells – when starting the car, you may notice gas smells due to blockage or dry filters, with the gases coming into the cabin from the exhaust.
- Unusual Engine Sounds – strange popping and coughing sounds when slightly pressing the gas pedal is often a sign that there isn’t enough air coming in. This usually points to a clogged filter and resultant timing issues.
- Check Engine Light – this can mean hundreds of different things, but when a blocked or dirty filter is the cause of inefficient combustion, the ECU will sense reduced amounts of air and trigger the check engine light. The amount of air is measured bt numerous sensors, such as MAP and MAF sensors in the intake and Oxygen sensors in the exhaust.
Changing a blocked or dirty filter is done for a few reasons. A new one will return unreasonably high fuel consumption to quoted factory levels and the engine runs the right fuel ratios, so there are no added emissions of toxic particles. What’s more important for the majority of drivers is that an auto air filter prolongs engine life. As mentioned, most car manufacturers will have quoted intervals when these need to be replaced. But if you sense any of the issues above, don’t hesitate to check the quality and condition of the filter and clean or replace it if needed. Getting auto air filters online is one way to speed up the whole process.
The filter should be removed with the engine off and cooled, and the whole procedure takes less than ten minutes. First, remove the housing fasteners, take out the dirty filter, clean the housing inside and out with a dry cloth, and install the new one (in the right type and size) back into the housing, ensuring it’s facing the right way. Then, redo the fasteners. Cabin air filters may take a little longer. Most are behind the glovebox. Remove any fasteners and trim holding the glovebox in place, pull out the old one, and replace it with the new one.
Final Word
Air filters are an essential vehicle component assigned one critical task: cleaning the air from various contaminants. A clogged, worn, or dirty filter can mean bad cabin air quality, or serious performance and engine issues if not taken seriously. When replacing the factory filter, ensure you have the right type and size for your vehicle and driving environment.
