What Happens When the Air Filter Gets Dirty?

[DominicLee]

When the air filter is dirty, it can lead to insufficient air intake, incomplete fuel combustion, unstable engine operation, and symptoms such as a muffled engine sound when continuously pressing the accelerator pedal, sluggish acceleration response, weak operation, and thick, black exhaust emissions. Below are specific details about the air filter: 1. Function: The car air filter is installed in front of the carburetor or intake pipe to filter the air entering the engine. During operation, the engine draws in a large amount of air, which contains many dust particles. Without filtration by the air filter, this can accelerate wear on the piston group and cylinder. The car air filter serves to remove dust and particulate matter from the air, ensuring that sufficient clean and dry air enters the cylinder. 2. How to Determine if It's Dirty: You can check the surface color of the air filter. If the filter paper remains gray-black after cleaning the surface dust, it indicates that the filter paper can no longer be used and should be replaced immediately.

[McBrooke]

I've noticed many car owners tend to overlook air filter issues. When it gets clogged, the most obvious symptom is the car 'breathing' with difficulty – you'll feel the engine struggling when accelerating, especially noticeable during hill climbs. Last time I encountered an owner complaining about a 15% fuel consumption spike. Upon opening the air filter box – wow – leaves and poplar fluff had nearly turned the filter into a carpet. When the engine can't get sufficient air, gasoline combustion becomes incomplete. Prolonged operation like this may even cause black smoke from the exhaust and worsen carbon buildup problems. Now I make it a habit to check my filter every 5,000 km, and in dusty areas I replace it even earlier.

[Mike]

As a mom who drives her kids to school every day, I'm most afraid of strange odors in the car. Once when I turned on the AC, I kept smelling a musty earthy smell. The technician said it was because the filter was too dirty and had grown mold. He took it out to show me on the spot—the filter paper had turned black, with dust mixed with dead insects. What's even scarier is that these contaminants can directly enter the AC ducts, causing my child to sneeze constantly while sitting in the car. Now I've developed a habit: I always check the filter before rainy seasons and after sandstorm days, because the air quality inside the car directly affects my family's health.

[DiArianna]

A veteran mechanic with 20 years of experience tells you, don't underestimate this small part—it could potentially ruin your engine. The worst case I've seen: a hole in the filter allowed sand and stones to enter the cylinder, damaging the piston rings. The overhaul cost over 8,000! Modern cars have highly precise intake systems—the air filter acts like a mask for the engine. A clogged filter harms the engine, while a broken one lets in debris. Regular replacement is the best preventive measure.

[DeLondon]

Every car enthusiast who's into modifications knows that the condition of the air filter directly affects acceleration performance. Experiments have shown that a dirty filter can slow down the 0-100 km/h acceleration by 0.5 seconds. Especially on track days, for every 1°C increase in intake air temperature, power output decreases by 1%. Our racing team cleans the filter after every run and replaces it every three sessions. Street drivers might not notice it as much, but the engine roar becomes muffled, and the ECU automatically reduces torque to protect the engine.