Why do some car exhaust pipes smoke in winter?

The exhaust pipe will smoke

As the weather gets colder and colder and the temperature drops, various seasonal diseases appear on the car. For example, sometimes the car is driving well on the road and the exhaust pipe suddenly smokes. What's going on here? Let's have a good analysis of this problem with you.

In fact, smoking in the exhaust pipe of a car in winter is as normal as dripping in the exhaust pipe in summer. Because of the low temperature in winter, water vapor will be discharged from the cylinder when the car is just ignited, and then it will condense into water mist when it meets the cold exhaust pipe, so we will see white smoke coming out of the exhaust pipe.

So why do some cars smoke and some don't? In fact, this has a lot to do with the exhaust volume and exhaust temperature of the car. Some cars have long exhaust pipes and good cooling effect. In addition, the driving distance of the car is relatively short, so you can't see this smoking phenomenon.

However, some cars have short exhaust pipes and long driving distances, so the cars are always in a hot state. When the exhaust gas passes through the exhaust pipe, there is no obvious cooling, and the exhaust pipe will emit white smoke. Therefore, when people see white smoke from the exhaust pipe, they don't have to be too alarmed, which just shows that gasoline burns very fully.

But if there is a lot of white smoke in the exhaust pipe of the car after the hot car, it is likely that there is something wrong with the car. A lot of white smoke is caused by the following two reasons. The first reason is that the cylinder gasket is damaged. When the cylinder gasket is damaged, the sealing degree between the cylinder block and the cylinder head is not tight, which will lead to the direct flow of coolant into the oil circuit. At this time, the water in the cylinder will form steam after evaporation, and these steam will be discharged in the form of a large number of "white smoke" with the help of the exhaust pipe.

The second is to add inferior gasoline, which causes a lot of white smoke in the exhaust pipe. Generally, the moisture index of inferior gasoline seriously exceeds the standard. When the water content in gasoline is too high, the gasoline sprayed from the fuel injector will become a lot of water vapor after high temperature, so a lot of white smoke will be emitted from the exhaust pipe. In addition, we will obviously feel that the power of the car is declining and the acceleration is weak. In this case, everyone must change the gasoline in time.

In addition to white smoke, blue smoke sometimes comes out from the exhaust pipe of a car. When this happens, everyone must pay attention to it. This situation is mostly caused by engine oil burning. This means that the automobile engine is likely to have problems such as too much oil, aging of valve oil seal, and too large gap between piston ring and cylinder wall, so it must be overhauled in time.

In addition, the automobile exhaust pipe sometimes emits black smoke, which is mostly caused by the failure of the automobile throttle position sensor or oxygen sensor, as long as it is repaired in time.