What is the reason for brief blue smoke during cold start?

[LaNolan]

The reason for brief blue smoke during cold start is oil burning, which indicates that engine oil enters the cylinder combustion chamber but cannot be fully burned, resulting in blue smoke being emitted from the exhaust pipe. Blue smoke is a serious symptom of oil burning. When this occurs, the cause should be immediately inspected and repaired. Engine oil is referred to as the lifeblood of the engine, serving not only a lubricating function but also roles in cleaning, sealing, buffering, rust prevention, and heat dissipation. An engine cannot operate normally without oil. During engine operation, oil forms a thin film on the surfaces of various components, preventing direct contact and friction between them.