OEM Part Number: 21430-7999C
While the radiator cap is just a tiny component of your vehicle’s cooling system it plays a critical role in helping the engine keep its cool. If you’re wondering whether a bad radiator cap can cause overheating, the answer is a definite yes.
Air pockets in the cooling system from an ineffective seal (such as one in a bad radiator cap) or a lack of sufficient pressure can cause the engine to overheat. The latter lowers the boiling point of coolant which makes it unable to absorb enough heat from the engine. If you see the temperature gauge on the dashboard rise, it’s wise to stop driving as soon as it’s safe to do so and wait for the engine to cool before continuing (or call a tow truck).
If you notice an unexplained coolant from your vehicle’s cooling system or you find your vehicle’s engine is running a little hotter than usual, there could be a problem with the radiator cap.
Please note: Since the cooling system is hot and under pressure when the vehicle has been running, it is very important that you never open the radiator cap until the vehicle has cooled completely. If you attempt to remove the radiator cap while the engine is warm, the coolant (likely as hot as boiling water) would shoot out and could seriously injure you; third-degree burns are a very real possibility.