What are the symptoms of a radiator cap not releasing pressure?

[DiCassidy]

Here are the symptoms of a radiator cap not releasing pressure: 1. Coolant easily overflows from the cap. 2. A radiator that does not release pressure can affect the engine's performance and, to some extent, its cooling efficiency. 3. If the temperature gauge shows a rapid rise in temperature, it is likely caused by the radiator cap not releasing pressure. Additional information: Here are the functions of a radiator cap: 1. Sealing: Under any operating condition, the radiator cap must prevent coolant from leaking out. 2. When the coolant temperature rises: The pressure inside the radiator increases to a certain value, and the radiator cap automatically opens the pressure relief valve, allowing excess coolant due to thermal expansion to flow into the auxiliary reservoir. 3. When the coolant temperature drops: Due to the contraction of the coolant, a negative pressure forms in the radiator, and the radiator cap automatically opens the return valve, allowing the supplementary fluid from the auxiliary reservoir to flow back into the radiator.