Why don't old cars recommend cleaning up carbon deposits?

It is not recommended to clean up the carbon deposits on old cars, because it will cause structural damage and performance degradation to the engine.

Cleaning up the carbon deposits in old cars will lead to an increase in exhaust pollutant emissions. Usually, the increase of exhaust pollutant emissions will only be found during the annual inspection of automobiles. At present, only carbon monoxide, hydrocarbons and nitrogen oxides are detected, and all three indexes can rise or exceed the standard when carbon is deposited, which may appear earlier than the decline of power and the increase of fuel consumption.

Various structures that constitute the combustion chamber in the cylinder are the main parts where carbon deposition occurs, including piston crown, spark plug, in-cylinder fuel injector, intake and exhaust valves and cylinder inlet of intake pipe. Carbon deposition in spark plug weakens the ignition ability or leads to ignition failure, and the pressure drop caused by air leakage in cylinder (at valve and piston) is obvious at high load or low speed.

The increase of fuel consumption and the decrease of power will be accompanied by a certain increase of fuel consumption, because it is necessary to increase the throttle opening and the corresponding fuel supply when obtaining the same power as before the influence of carbon deposition. Therefore, when the fuel consumption increases for unknown reasons, it is necessary to check whether there is carbon deposition in the cylinder.

Reasons for carbon deposition:

1, car owners have long-term bad driving habits, and many car owners are reluctant to step on the accelerator to save fuel, which will not only save fuel but also increase engine carbon deposition. Because the car runs at a low speed when it is in a high gear, it not only damages the gearbox, but also increases the carbon deposition in the engine cylinder and consumes fuel for a long time.

2. The poor quality of automobile fuel causes the formation of carbon deposits in the engine, which is easy to block the throttle and injector, causing serious damage to the engine, especially the fuel system, and greatly shortening the service life of parts.

3. The carburetor of the engine is aging or damaged. Whether gasoline can be fully burned in the engine mainly depends on whether the carburetor can atomize gasoline into fine molecules. If the carburetor is aging or faulty, it will cause gasoline to enter the engine for combustion without sufficient atomization, which will lead to the formation of carbon deposits.