What are the effects of overfilling coolant?

[Lawrence]

Excess coolant can be drawn out from the expansion tank; overfilling coolant has no significant impact on the engine. Additional information: 1. Consequences of overfilling coolant: There is a drain pipe on the expansion tank. When excessive coolant causes excessive pressure, this drain pipe acts as a pressure relief, and the excess coolant will also be discharged through this pipe. 2. Insufficient coolant: If the coolant level drops below a certain point, it will not be sufficient to meet the engine's normal cooling requirements. If coolant is not added at this time and the vehicle continues to be driven, the engine temperature will rise rapidly, significantly increasing the risk of engine piston scuffing and seizure.