A vehicle air filter is an easy to replace project but many times forgotten. An internal combustion engine needs air to be mixed with the fuel. This air comes in through the air filter. Without adequate air intake, the fuel mixture will be too rich with gas to burn properly, and the engine can be starved of needed oxygen.
Most automobile manufacturers recommend the air filter be replaced every 12,000 miles or every 12 months, whichever comes first. If you live in an agricultural area, an area high in dust or any location where there is a lot of impurities in the air, you should consider changing your air filter more frequently. These filters are usually made of layers of filter paper. You might remove the dirt from the outside layer, but the inner layers can still be clogged. Because filters are relatively inexpensive, it is usually better to replace than try to clean them.
There are problems associated with a clogged or dirty air filter, and the symptoms can be different depending on the size and type of engine you have in your vehicle.
If you are seeing black smoke exiting the exhaust pipe, this can be a symptom of a clogged air filter. With the reduced oxygen, the mixture will be too rich. In other words more fuel will be used in the combustion leading to black soot like residue being sent out of the exhaust.
If the engine sounds like it is missing or running roughly, it can be caused by spark plugs not firing. One cause of this is the spark plugs are not firing due to the head covered with black soot residue left on the spark lead from the rich fuel mixture – which is a result of a dirty or clogged air filter.
If you hear the sound of an explosion or something that sounds like a gunshot coming from the exhaust pipe, this again is caused by the rich fuel mixture and some unused fuel exiting the engine into the exhaust system and then igniting from the heat. You might even see a flame at the end of the exhaust pipe. Again, probably caused by a air filter than needs to be replaced.
With the lower oxygen in the mixture, the engine will use more fuel than needed to run the engine. This will cause the mileage per gallon ratio to decrease significantly.
When starting the vehicle, if there is a smell of gasoline, this is again caused by the lack of air getting into the carburetor or fuel ejection system. With this reduced quantity of oxygen there will be fuel unneeded for the combustion being blown out in the exhaust.
A simple item that often overlooked in the maintenance of a vehicle is so critical to its performance. Lower gas mileage, burnt parts, and even flames shooting out the rear of the vehicle can all be prevented from occurring. With a routine inspection and replacement of the air filter, you can increase your fuel efficiency and help the car run better and longer.