What Causes White Smoke from a Car Engine?
2 Answers
There are many reasons for white smoke emission, mainly including the following aspects: 1. Engine temperature too low: Some diesel fuel turns into oil vapor without burning and is discharged with exhaust gas from the exhaust pipe, resulting in white smoke. 2. Water in the fuel supply system: Presence of water in the fuel or combustion chamber causes it to be heated into steam by the combustion heat in the cylinder, forming white smoke when discharged from the exhaust pipe. 3. Overly delayed fuel injection: Late injection timing means the cylinder temperature has already dropped when fuel is injected, causing some diesel to turn into vapor without burning, leading to white smoke. 4. Poor fuel injector atomization: Inadequate atomization prevents complete combustion of diesel, which then mixes with high-temperature exhaust gas from normally operating cylinders in the exhaust pipe, producing white smoke. 5. Low cylinder pressure: Some diesel turns into oil vapor without burning, thus emitting white smoke from the exhaust pipe.
I've been driving for many years and have encountered quite a few similar issues. White smoke from the engine is usually a sign of cooling system problems, such as coolant leaking into the combustion chamber and burning. This could be due to aging engine gaskets leaking water or cracks in the radiator. If not addressed promptly, the engine is prone to overheating damage, and replacing the entire engine could cost tens of thousands. Once, my car had the same issue, and when I stopped to check the coolant reservoir, I found it nearly empty. I quickly added some purified water as an emergency measure, but still had it towed for repairs to be safe. I usually check the coolant level regularly to avoid accidents during summer or long trips. My advice is that if you notice continuous white smoke (not just the usual fog during cold starts), it's best to stop the car and have a professional mechanic diagnose it—don't risk major damage for minor neglect.
