How does the engine remove carbon deposits?

How does the engine remove carbon deposits?
When the engine works normally, the vehicle is always in the state of walking and walking under the condition of hypoxia, that is, under the crowded urban road conditions, the engine cannot run at high speed, and the gasoline and oil that normally enter the combustion chamber cannot completely enter the cylinder. During combustion, the oil smoke and burnt lubricating oil particles produced by them will be further oxidized and become glue to stick on the intake pipe, throttle body, internal surface of intake pipe, fuel injector, valve back, spark plug, piston top, piston ring and combustion chamber wall. Under the repeated action of high temperature, the colloid will become asphaltene, resin and carbon, and finally form engine carbon deposit. The long-term and short-term operation of the engine, the long-term operation of the vehicle in a harsh environment, the long-term low temperature and low speed driving, and the long-term high temperature, high speed and overload conditions will aggravate the carbon deposition.