For 1990-2009 cars

Problem | Action
--- | ---
The air compressor cylinder head intake cavities, discharge cavities or in the discharge pipe are restricted. | Remove the restriction and clean.
The discharge valves are leaking or broken. | Replace or repair the air compressor.
Inlet valve is stuck open. | Replace or repair the air compressor.
The inlet valves are worn. | Replace or repair the air compressor.
The system has excessive leakage or usage. | Check for leaks and repair as needed.
The engine air filter is dirty. | Replace the engine air filter.
The air compressor air strainer filter is dirty. | Replace the air compressor air strainer filter.