What Causes Sudden Smoke from a Car?
2 Answers
There are several situations where smoke may emerge from a car's engine hood: 1. Small fuel injection advance angle: caused by incomplete combustion; slight water leakage in the cylinder liner or water presence in the fuel. White smoke during cold starts, especially at low temperatures, is normal if it disappears as the engine warms up. 2. Air-fuel ratio imbalance: decreased cylinder pressure; early fuel injection timing (excessive fuel injection advance angle) can cause black smoke; failure of the smoke limiter on the fuel injection pump can also result in black smoke during rapid acceleration; malfunctioning exhaust brake system. 3. Burning oil: Blue smoke from the car engine is often due to "oil burning," which requires checking for cylinder liner wear, "stuck rings," ring misalignment, aging or deformed valve seals, excessive valve guide clearance, etc. This condition is usually accompanied by crankcase blow-by.
When a car suddenly emits smoke, my first thought is safety first. Immediately pull over to the side of the road, turn on the hazard warning lights, and move away from the vehicle to prevent potential explosions. There could be many reasons, with the most common being engine overheating due to insufficient coolant or a broken fan, causing a hose to burst and emit smoke. It could also be an oil leak dripping onto the hot exhaust pipe, catching fire and producing thick smoke. Other possibilities include electrical short circuits, battery issues, or transmission system failures that can trigger smoke. Last week, I encountered a similar situation where the brake pads were worn out, causing excessive friction and overheating, resulting in smoke. Remember, don’t casually open the hood yourself, as it can easily lead to burns or fires. First, turn off the engine and disconnect the power, then check the warning lights on the dashboard. Regularly monitoring coolant temperature and oil levels can help avoid such troubles. In case of such emergencies, calling a tow truck or seeking professional help is the safest option—never risk driving home under such conditions, as the risks are too high.
