Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to wash under the hood of a car [title] Make sure the engine is cold. [step] The only time you should wash under the hood is when the engine is cold. This means that you need to wait a substantial time after running the engine and washing under the hood.

Ending1: [substeps] If the temperature falls below freezing, the engine will then become very cold so it would be easier to clean under the hood. So you will have to wait until the engine runs very cold for a full 10 minutes to let your engine warm up. Ending2: Having the engine completely cold means that you must remove the heat source before you begin washing under the hood. [substeps] If you are going to wash under the hood on a vehicle that will be traveling at high temperatures, check to make sure the radiator is also at room temperature. Ending3: To avoid this, warm the engine up with a heat-proof bulb. The bulb should not be cold enough to release, or melt, the needed heat. Ending4: If you wash it when the engine is hot, you run the risk of damaging your engine as cold water may cause hot or warm parts to shatter or be damaged. [substeps] The best time to wash under the hood is in the morning after your engine has cooled all night.

Answer format: ending1/ending2/ending3/ending4