The cylinder heads, cylinder liners, pistons, piston rings, valves, fuel injectors and other parts of the diesel engine and the combustion chamber will adhere to a layer of coke after being used for a period of time. Coking is a complex mixture formed due to incomplete combustion of diesel oil and oil infiltrating into the cylinder. It has a dense, loose, soft, etc. form, the color from black to gray, the temperature of the formation site is about 200 °C. Forklift mechanical removal method.

The use of wire brushes, scrapers, bamboo or emery cloth to remove coke. Special brush and scraper can be made according to the shape of the parts to be cleaned: For example, the carbon deposits around the nozzle holes of the injector can be brushed with fine copper wire; the special carbon needle made of copper wire can be inserted into the pressure chamber for carbon deposition. Scraping; carbon deposits on valve guides and valve seats can be removed with a cylindrical metal brush.