Why Can't You Start a Car After It's Been Submerged in Water

[SebastianAnn]

To prevent water from entering the engine and causing severe consequences. Here are the relevant explanations: 1. The engine will inevitably stall after water enters: Since water entering the cylinders lacks lubricating properties, blindly restarting the engine after stalling may cause the engine to seize due to cylinder scuffing, leading to complete failure. 2. Check the fluid conditions of various vehicle systems: This prevents phenomena like foaming or cloudiness after water ingress, which can cause engine oil deterioration and loss of lubrication. Additionally, water may carry sand particles, causing excessive engine wear. In such cases, immediate cleaning and replacement are necessary. After inspection, clean the electrical connection components inside the engine compartment to prevent corrosion caused by water accumulation and residual sand particles at these connections.

[Ronald]

I found that when a car is flooded, you shouldn't rush to start the engine. The main reason is that water can enter the engine cylinders, and when the piston compresses, it can get stuck, causing severe engine damage. This is called hydrostatic lock. If you force ignition, internal engine components may break, leading to complete engine failure. Additionally, water can easily short-circuit electronic systems, such as the ECU (Engine Control Module) and sensors, causing further malfunctions. I've seen many cases while working in auto repair where flooded cars were started, resulting in skyrocketing repair costs—ranging from thousands to tens of thousands of dollars. My advice is to never attempt to start the car. Instead, have it towed to a professional shop for water drainage and inspection to ensure safety before proceeding. This way, you avoid unnecessary expenses and hassle.

[JustinFitz]

Friend, if your car gets flooded, don't attempt to start it - this is no trivial matter. Water can damage the ignition system and electronic components. If the ECU gets flooded and short-circuits, the entire vehicle may become inoperable. Even more dangerous is hydrostatic lock in the engine - when pistons try to compress water that's hard as stone, the engine can snap instantly. A relative of mine experienced this - after attempting to start, the engine was completely totaled, costing as much as a new car. Safety first - just call a tow truck to take it to the repair shop for proper drainage and thorough electrical inspection. Protect yourself and your wallet - don't take the risk.

[RileyLee]

From my own car repair experience, starting a flooded car is asking for trouble. Water entering the cylinders causes hydro lock, preventing compression and immediately breaking piston bearings. Electrical systems will also short-circuit and burn out, especially the ECU and air sensors, making repairs complex and time-consuming. Simple advice: Don't touch the ignition key, tow it away immediately to check all systems, and avoid greater losses.