What could excessive white smoke from exhaust indicate when the engine is at operating temperature?

Excessive white smoke from the exhaust at operating temperature is a strong indication of coolant being burned in the combustion chamber, which typically suggests a blown head gasket. The head gasket seals the engine block and cylinder head, maintaining the necessary compression and preventing coolant and oil from mixing. If the gasket is compromised, coolant can leak into the combustion chamber, resulting in white smoke as the coolant vaporizes and is expelled through the exhaust.

This situation is often accompanied by other symptoms such as increased engine temperature, loss of coolant without visible leaks, or milkshake-like oil indicating coolant contamination. Recognizing these signs is crucial for diagnosing and addressing potentially severe engine damage that could occur if the issue is not rectified promptly.