What symptom might indicate a coolant leak?

Identifying a coolant leak is crucial for maintaining the engine's performance and preventing serious damage. The presence of white residue around engine components is a significant indicator of a coolant leak because this residue typically forms when coolant comes into contact with hot engine surfaces. The heat causes the coolant to evaporate, leaving behind a white powdery substance, which is usually mineral deposits from the coolant itself.

In contrast, excessive exhaust smoke may indicate a variety of engine problems, such as oil consumption or incomplete combustion, but it is not a distinct sign of a coolant leak. An overheating engine can result from many issues, including low coolant levels, but it does not diagnose the presence of a leak specifically. Low oil pressure may suggest problems related to oil circulation or lubrication but is unrelated to coolant leaks. Thus, the presence of white residue serves as a clear and specific symptomatic indicator of coolant leakage.