When it's working properly, the radiator cap helps normalize the pressure within the cooling system and keeps the engine cool. If the cap can't maintain the correct pressure for your vehicle, the engine will start to overheat. An overheating engine could also be a symptom of air pockets within the cooling system.

What are the signs of a bad radiator cap?

Can a worn radiator cap cause overheating?

The radiator cap is often overlooked as being a cause of engine overheating. ... A faulty radiator cap can result in engine overheating, loss of coolant or major engine damage. So, Pressurized cooling systems help prevent overheating and coolant loss.