In fact, we can roughly judge whether a vehicle is "healthy" from the exhaust color of the vehicle. Many car owners are likely to encounter a sudden large amount of white smoke from the exhaust pipe when using the vehicle. Is it normal for the exhaust pipe to emit white smoke? Here is a detailed analysis of several common situations.

其實不一定說排氣管冒白煙就是出現機械故障，我們需要分情況去考慮。

In fact, it does not necessarily mean that white smoke from the exhaust pipe is a mechanical failure. We need to consider it according to the situation.

1、冷啟動時排氣管突然冒大量白煙。這種情況非常正常，因為汽車冷啟動時汽油中的水分太多，所以啟動后水分會被蒸發出來導致排氣管有大量白煙，我們只需要充分熱機之后這種情況就會消失；

1. During cold start, the exhaust pipe suddenly emits a lot of white smoke. This situation is very normal, because there is too much water in the gasoline during the cold start of the car, so the water will be evaporated after the start, resulting in a lot of white smoke in the exhaust pipe. We only need to heat the engine fully, and then this situation will disappear;

2、排氣管冒藍煙。這種情況就不太正常了，冒藍煙通常就證明發動機存在燒機油現象，機油與汽油共同燃燒導致污染加重。燒機油的主要原因是因為發動機活塞環老化氣密性降低，機油有機會進入到燃燒室參與燃燒過程；

2. The exhaust pipe emits blue smoke. This situation is not normal. Blue smoke usually proves that the engine burns engine oil. The CO combustion of engine oil and gasoline aggravates the pollution. The main reason for burning engine oil is that the engine piston ring is aging and the air tightness is reduced, so the engine oil has the opportunity to enter the combustion chamber to participate in the combustion process;

3、排氣管冒黑煙。出現排氣管冒黑煙情況大多數是因為燃油無法充分燃燒所導致，這時候可以選擇開到維修店去檢查一下。當然汽油質量太差也會造成這種現象的出現。

3. The exhaust pipe emits black smoke. Black smoke from the exhaust pipe is mostly caused by insufficient fuel combustion. At this time, you can choose to drive to the maintenance shop for inspection. Of course, the poor quality of gasoline will also cause this phenomenon.

在冬季時排氣管冒白煙是很正常的，這就像我們冬季呼氣時會產生白霧一樣，排氣管的溫度比較高，當遇道較冷的空氣時就會出現凝結現象，因此我們在冬季時發現車輛比平時冒更多白煙的話不用太過擔心。總的來說，除了冬季冒白煙和冷啟動冒白煙之外，其余情況都很有可能是發動機出現故障，需要盡快進行維修。

It is normal for the exhaust pipe to emit white smoke in winter, just like white fog when we exhale in winter. The temperature of the exhaust pipe is relatively high, and condensation will occur when we encounter colder air. Therefore, we don't need to worry too much if we find that the vehicle emits more white smoke than usual in winter. Generally speaking, except for white smoke in winter and cold start, it is likely that the engine fails and needs to be repaired as soon as possible.