Why is it dangerous to pour water on an engine fire?

Pouring water on an engine fire is particularly dangerous because water can spread burning oil. If there is an oil leak or if the fire involves burning oil, adding water can cause the oil to splash and spread the flames, potentially worsening the situation. This is because oil and water do not mix; when water is applied, it can cause the burning oil to float and disperse, leading to a larger fire spread, making it harder to control the flames.

While other responses may sound plausible, they do not directly address the immediate risks associated with engine fires. For instance, while cooling the engine too quickly is a consideration in some contexts, it's not the primary concern during a fire. The potential for explosion or electrification of components is less likely than the spreading of flames caused by oil, making the latter response the most critical to understand in dealing with such emergencies.