Will the engine definitely be damaged if it is started a second time after water ingress?
2 Answers
Starting the engine a second time after water ingress does not necessarily mean it will be damaged. If the vehicle stalls during wading, do not attempt to restart it. Below are some additional details: Water in the air filter: If the engine can still be started after wading, but the air filter has taken in water, the engine may inhale some moisture along with the air. This moisture forms steam, and when mixed with gasoline, it can combust fully, which generally does not significantly affect the engine. A small amount of water entering the engine: If water reaches the cylinders and mixes with the engine oil, the oil quality will deteriorate. Water in the oil can increase wear on engine components, potentially leading to louder engine noise and greater vibration while driving. Starting and then stalling: If the engine starts but stalls again after a few seconds, and subsequent attempts to restart fail, this is the most severe scenario. Since water cannot be compressed, its presence in the cylinders during high-speed operation can cause severe damage, such as bending the valves and connecting rods, seizing the pistons, significant cylinder wear, and even bending the crankshaft.
I've seen quite a few cases of water-damaged engines being restarted in the workshop. They don't always fail, but the risk is real. If the water intake is minimal and the engine starts slowly, it might survive. But once water gets trapped in the cylinder, the restricted piston movement can bend or break the connecting rod. Last time, a guy insisted on restarting, and the engine seized up—costing over ten grand to fix. My advice: don't rush to start after water exposure; call a tow truck immediately for safety. For prevention, avoid deep water while driving and regularly check if the air filter is dry. Bottom line: it's not worth the gamble—professional repair is the safest approach.
