First check whether the water tank cover has been fastened, and try to fill the car radiator with air to see where the water in the water tank seeps out when it is pressurized. Unscrew the engine oil cover to see if there are traces of inorganic oil emulsification. Disassemble the engine and replace the cylinder head gasket. If you find that the water tank is leaking, you can go to the auto repair shop to check and replace the water tank with a new one to avoid other car repair failures.