No sooner had the car changed the spark plug to clean the accelerator than the hot car emitted white smoke.

White smoke from the engine indicates that there is water in the cylinder. There may be cracks and sand holes in the water channel of the cylinder bed or cylinder body, and a small amount of water may seep into the cylinder after the cold car stops, and then the water will be burned into white steam after the cold car starts. If too much water seeps into the cylinder after a long time, the piston may be sucked to death and cannot be started. Shake it with a crowbar and the car will come again (a burst of white smoke). After the hot car, the temperature is high, the water vapor evaporates quickly, and no white smoke can be seen.