What Can a Bad Air Filter Cause?

A bad air filter can cause a range of issues, from harmful emissions to fuel waste, damaged spark plugs, and engine buildup. It's important to monitor parts that suffer from a lot of wear and tear, as engine misfires, rough idling, and hard starts can all be attributed to a clogged engine air filter. The dirty air filter restricts air supply to the engine, causing unburned fuel to form a soot residue that accumulates in the spark plug. This fouls the spark plug(s) and decreases its ability to produce the spark needed for the combustion process.

Changing the affected air filter and spark plugs will restore your engine's performance. A dirty air filter decreases the amount of air supplied to the engine. This can cause an increase in unburned fuel that becomes soot residue. Soot can build up on the tips of the spark plugs, making them unable to produce a proper spark.

In return, the car may move abruptly, idle, and in some circumstances, the engine may fail. Decreased fuel economy is a clear sign of a faulty or dirty air filter. A dirty or bad air filter restricts airflow, which reduces oxygen in the mixture. Your engine compensates for this by consuming more fuel to produce enough power to move the same distance or speed as it could with a clean filter.

At worst, a faulty air filter can create slow driving performance in a modern car. If you have a clogged air filter, one of the symptoms you would experience is a reduction in engine performance. It is one of the telltale signs, since the restriction in airflow forces the entire engine to run at low power to maintain the stoichiometric fuel ratio. Most automotive companies recommend changing the air filter every 10,000 to 15,000 miles or every 12 months. However, if you normally drive in dusty or rural areas such as Scottsdale, Arizona or San Antonio, Texas, it's a good idea to have your mechanic check and change it more often - for example, every 6,000 miles. Driving in busy areas where there is a lot of traffic - including Los Angeles and Washington DC - making it stop and start more often also requires you to replace the air cleaner more often. Most vehicles also have a cabin air filter that is used to clean the air entering the interior of the car, but it has a different maintenance program than an engine air filter. If you start to hear coughing or clicking noises coming from the engine compartment, or if your vehicle vibrates excessively, it could be a symptom of a dirty air filter damaging a spark plug.

If you drive an older carburettor vehicle, a drop in fuel economy is a common sign that the air filter is dirty. If you discover that your air filter needs a change, it is advisable to also check the condition of the spark plugs to see if they have also suffered any damage. Replacing your home's air filters regularly is one of the simplest yet most powerful and effective ways to protect and preserve expensive systems that heat and cool your home and keep your family comfortable during hot summers and cold winters. To do it yourself, first refer to the owner's manual for the location of the filter and refer to this step-by-step guide to removing the air filter. Most manufacturers recommend replacing the air filter every 12,000 miles (approximately 19,000 km) or every 12 months - whichever comes first. If you see black smoke coming from the exhaust pipe, ask your mechanic to change or clean the air filter. Replacing an air filter is actually one of the easiest DIY tasks you can perform on your vehicle - so 95% of people should be able to do it themselves.

If you notice your car vibrating excessively or you hear coughing or clicking noises coming from your engine compartment - it's often due to a clogged air filter that dirties or damages a spark plug. As a car owner, you need to be aware of all these symptoms of dirty air cleaner in order to ensure your engine stays free of debris.

Jo Burgey
Jo Burgey

Lifelong beer expert. Passionate music fan. Evil internet nerd. Passionate zombie nerd. Infuriatingly humble social media ninja.