To check the coolant level, first, ensure that the engine is cool. Locate the coolant reservoir, usually a translucent plastic tank with markings indicating minimum and maximum levels. If the coolant level is below the minimum mark, add a mixture of coolant and distilled water to bring it up to the recommended level. It’s important not to open the radiator cap when the engine is hot, as it can cause severe burns. Regularly inspect the coolant for signs of contamination, such as discoloration or debris, and address any issues promptly.