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How Long to Wait for Car to Cool Down Before Opening the Radiator Cap? (Explained)

Updated: Feb 2

✔ This article has been fact checked.

The radiator cap is also known as the pressure cap, it is placed on top of the radiator and is responsible for maintaining the correct pressure within the cooling system.

Opening the radiator cap while the engine is hot can be dangerous, as it releases pressure and steam, which can cause severe burns.

You should wait at least 30-60 minutes for the car to cool down before opening the radiator cap. This is to ensure that the coolant inside the engine has cooled down to room temperature and the pressure inside the cooling system has decreased.

However, if the engine has overheated, it is important to wait longer before opening the radiator cap, as the coolant may be under even higher pressure. In this case, it is recommended to wait at least 2-3 hours for the engine to cool down before attempting to open the radiator cap.

In this article, we will discuss how long you should wait for a car to cool down before opening the radiator cap.

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a person opening a car radiator cap