What is the reason for BMW's failure to start after wading through water?

[VanManuel]

BMW's failure to start after wading through water can be attributed to the following reasons: Water ingress in the air filter: The engine can still start after wading through water, but if water enters the air filter, the engine may inhale some moisture, forming steam. The mixture of water vapor and gasoline can burn sufficiently, which does not have a significant impact on the engine. Water in the engine oil: If a small amount of water enters the engine and mixes with the oil, the oil quality will deteriorate. The presence of water in the oil can increase wear on engine components, potentially leading to louder engine noise and greater vibration while driving. Water in the cylinders: The most severe scenario is when the engine starts for a few seconds and then stalls, followed by repeated unsuccessful attempts to restart. This is because water cannot be compressed. If water enters the cylinders, it can cause the valves and connecting rods to bend, pistons to seize, severe cylinder wear, and crankshaft bending, especially when the engine is running at high speeds.