What are the symptoms of a cooling system leak?

The symptoms of a cooling system leak are accurately described by the signs mentioned in the second choice. Engine overheating occurs when the cooling system is not able to effectively regulate the engine temperature due to the loss of coolant from the leak. Coolant spots under the vehicle are indicative of a leakage point where the coolant escapes from the system, making it visible on the ground. Low coolant levels directly result from this leakage, as the coolant is essential for maintaining adequate engine temperature and preventing overheating.

By understanding these symptoms, mechanics can diagnose cooling system issues more efficiently. The other options do not pertain to cooling system leaks; frequent oil changes relate to engine lubrication issues, abnormal tire wear points to alignment or tire pressure problems, and excessive engine noise might indicate mechanical issues unrelated to the cooling system. Thus, recognizing the specific symptoms of a cooling system leak is crucial for effective vehicle maintenance and repair.