A car has trouble, but it doesn't know where the problem is. This is a problem often encountered by owners. Mastering the basic common sense and methods of finding problems, using their own vision to find fault in time, to solve the problem at the beginning of the problem, not only reduce the time of the damage of the car, but also prevent the further expansion of the fault, save time and save money, and protect the love of the car. In the winter morning, it is often seen that the vehicle starts to discharge white tail gas when the vehicle starts. This is due to the temperature in which the engine has not reached the normal operating temperature in the 61's temperature of the engine, and a small amount of water vapor accumulates in the exhaust pipe after a night of "sleep", and the result of the engine is produced after the engine is heated. When the engine temperature rises, the phenomenon of white smoke gradually disappears. However, if continuous smoking occurs, it is indicated that water or cylinder intake is used in the gasoline used by the vehicle. Natural factors lead to limited influent, but if the water tank is leaking or the pipeline is leaking, it needs to be carefully checked, otherwise the engine's operation efficiency can be discounted. It is common for a bus to smoke and smoke in the street in a few years. In fact, the black color of exhaust gas is a frequent occurrence of vehicles running for many years. The tail gas is black because the concentration of mixed gas in the cylinder is too high, and the incomplete combustion will manifest itself in the exhaust. If your car is an electric spray car to check an oxygen sensor, high lead can cause oxygen sensor failure; if it is a carburetor car also may be due to low engine temperature, carburetor improper adjustment, air filter block; individual cylinders do not work and ignition too late and so on. In short, there will not be a driver who likes to travel in a black smoke, or go to find out the exact cause of the disease. Many new owners love cars very much. When they add oil, they often hold the attitude of "more or less." but keeping cars and cars must be done according to the requirements of vehicles. Excessive oil not only increases the resistance of the mechanical operation, but also causes the oil to burn from the piston to the combustion chamber, but it can not be completely burned to form a blue smoke in the tail gas. If the owner does add oil according to the requirements of the car factory, it may be caused by the piston ring counterpart, the piston ring assembly, the piston ring bonding in the ring groove, the serious wear of the piston ring and the cylinder wall, the blockage of the crankcase ventilator, and the low viscosity of the oil. Exhaust gas is emitted after engine work, and its color will directly indicate the running state of vehicle. A vehicle with good working conditions can not see smoke from the rear of the car when you press the clutch and pedal the accelerator. Colorless tail gas not only reduces pollution to the environment, but also beautifies the appearance of cars.