What are the consequences of a broken car radiator cap?

[SanZane]

Coolant will spray out from the radiator cap; after the coolant sprays out from the radiator cap, the flow rate and pressure of the coolant entering the engine will decrease; due to the reduced coolant flow, the heat generated by the engine cannot be carried away by the coolant; the engine will overheat, leading to the engine cover opening; once the cover opens, the engine will suffer a certain degree of damage. The functions of the radiator cap: 1. Sealing: Under any working condition, the radiator cap must prevent coolant from leaking out. 2. Coolant expansion: When the coolant temperature rises, the pressure inside the radiator increases to a certain value. The radiator cap automatically opens the pressure relief valve, allowing the excess coolant caused by thermal expansion to flow into the auxiliary reservoir (the plastic tank in older models). 3. Coolant contraction: When the coolant temperature decreases, due to the thermal contraction characteristics of the coolant, a negative pressure will form inside the radiator. At this point, the radiator cap automatically opens the return valve, allowing the supplementary fluid in the auxiliary reservoir to flow back into the radiator.