What are the symptoms of a faulty expansion tank cap?

[LucyAnn]

Here are the symptoms of a faulty expansion tank cap: 1. After the expansion tank cap is damaged, coolant will spray out from the radiator cap. 2. When the tank cap is damaged, the flow of coolant entering the engine will decrease, leading to a drop in coolant pressure. The heat generated during engine operation cannot be dissipated, which may cause the engine to overheat. In severe cases, boiling over may occur. Below is some relevant information: 1. Most automotive engine cooling systems use an automatic compensation closed-type radiator, primarily equipped with a reservoir. The reservoir cap has a steam valve and an air valve. The advantage of this design is that it reduces coolant loss in the cooling system while improving the radiator's heat dissipation performance. 2. When the pressure in the cooling system exceeds the steam valve's pressure, the steam valve opens, and the radiator starts working. This helps lower the temperature around the engine, ensuring it operates within the normal temperature range. 3. When the engine is running, the coolant continuously circulates in the cooling passages. If the internal pressure is too high, the coolant may leak out, potentially causing pipe bursts. 4. The coolant reservoir has maximum and minimum level marks. When adding coolant, ensure it is filled between these two marks.