Engine ignition faults, sudden idling and sudden starts can all be attributed to a clogged engine air filter. This is because the dirty air filter restricts the air supply to the engine, causing unburned fuel to form a soot residue that accumulates in the spark plug. An engine misfire can significantly increase vehicle emissions, which is why the ECM (Engine Control Module) constantly monitors the engine's ignition fault status. If you detect an engine ignition fault, turn on the CEL (Check Engine Light).
Most automotive companies recommend changing your air filter every 10,000 to 15,000 miles, or every 12 months. However, if you normally drive in rural or dusty areas such as Scottsdale, Arizona or San Antonio, Texas, you might want to have your mechanic check and replace it more frequently - for example, every 6,000 miles. Driving in busy areas where there is a lot of traffic, such as Los Angeles and Washington D. C., which causes your car to stop and start more frequently, also requires you to replace the air filter more often.
Most vehicles also have a cabin air filter that is used to clean the air that enters the interior of the car, but it has a different maintenance program than an engine air filter. A dirty air filter reduces the amount of air supplied to the engine. This can cause an increase in unburned fuel, which is converted to soot waste. Soot can build up on the tips of the spark plugs, making them unable to emit a proper spark. In return, your car may move sharply at idle and, in some circumstances, the engine may misfire. Fortunately, because air filters are so simple, they don't cost as much as other engine parts.
This means that you can often save labor costs and replace the air filter yourself if you know where it is. This makes it essential for your mechanic to check the air filter when you bring your car in for maintenance. Because the engine air filter has a lot to do with the flow of air entering the engine and its cleanliness, many of the signs and symptoms of a faulty air filter are due to dirty air affecting other vehicle systems or to decreased airflow to the engine. An engine air filter keeps out dust and dirt that would otherwise wear out engine components, causing them to fail faster than if your vehicle didn't have an air filter. Contaminated air filters don't provide enough air, so the engine ends up consuming more fuel to overcompensate.
This air reaches the engine through an air filter that prevents debris, dirt, bugs and other road contaminants from entering that can damage the engine. If the engine air filter is faulty, your vehicle could perform poorly, conserve fuel, produce black smoke in the exhaust, cause an ignition failure or generate unusual engine noises. However, large objects, excessive dirt and water can damage an air filter prematurely under certain circumstances. Make sure your mechanic checks the air filter when you leave your car for maintenance and follow the manufacturer's instructions regarding replacing it. If you notice that your car vibrates excessively or you hear coughing or clicking noises, it's often due to a clogged air filter that dirties or damages the spark plug. There are not many things that cause air filters to fail unexpectedly since they are simple devices that have no active movement or mechanical or electronic components and are usually protected by an air chamber.
If the same problems occur over and over again there may be a bigger problem with your vehicle that has little to do with a dirty air filter. The engine air filter is often confused with the cabin air filter - the generally square fan-like device that Jiffy Lube employees always show you and say it should be replaced every time you change your oil. One of the best and easiest improvements you can make to your vehicle is to buy a reusable air filter such as a K&N filter.