A dirty air filter can have a significant impact on the RPMs of your car. When the air filter is clogged, it restricts the amount of quality air that can enter the combustion chamber. This can cause the RPMs to fluctuate more than 1,000, leading to engine flooding, spark plug contamination, and misfiring or starting problems. If you notice a rough idle or a reluctant start, it's important to check the air filter first.
A heavily clogged air filter can cause the engine to splash or even stall. When the engine cannot draw in enough air, it may experience an overly rich air-fuel ratio. This leads to an inefficient combustion process, with excess fuel remaining in the cylinders after each piston cycle. With an extremely rich air-fuel ratio, the engine can hesitate and sputter when accelerating and can even stall when lifting the throttle.
You may also notice a strong gasoline smell in your car's exhaust system when the engine is running. It's essential for your mechanic to check the air filter when taking the car for maintenance. Depending on the type of air filter you use in your car, you may need to clean or replace it. Replacing the air filter can improve acceleration or power by up to 11%, and it's one of the easiest DIY tasks you can perform on your vehicle.
If you find that your air filter needs a change, it's also advisable to check the condition of the spark plugs to see if they have suffered any damage. If the engine air cleaner is clogged, you may hear bursting, sputtering, or coughing noises. Defective or blocked parts, such as a dirty air filter or a clogged air intake pipe, can cause engine performance problems.