Why Shouldn't You Attempt to Restart the Engine After Driving Through Water?

[MilaMarie]

For safety reasons, avoid attempting to restart the engine. Below is a partial introduction on how to properly shut down a car: 1. Steps for shutting down an automatic transmission car: (!) Press the brake to ensure the vehicle is completely stopped, then shift the gear to N (Neutral). (2) Engage the parking brake. (3) Shift to P (Park), then release the brake. (4) Turn off all unnecessary electrical devices in the car. (5) Verify that the gear is in P (Park), all unnecessary electrical devices are turned off, and the steering wheel is straightened. (6) Turn the key counterclockwise to the end, or press the start-stop button once to set the ignition switch to the OFF position. 2. Steps for shutting down a manual transmission car: (!) Press the clutch and brake to ensure the vehicle is completely stopped. (2) Engage the parking brake and shift to neutral. (3) Release the clutch and brake. (4) Turn off all unnecessary electrical devices in the car and straighten the steering wheel. (5) Turn the key counterclockwise to the end, or press the start-stop button once to set the ignition switch to the OFF position.

[SanLilliana]

After driving through water, you really need to be careful not to attempt a second ignition. If water enters the engine cylinders, the piston's up-and-down movement relies on air compression. Water doesn't compress like air does, so when you try to start the engine, the piston hits the water column like a hard impact, which can cause the connecting rod to bend or even break, completely wrecking the engine. A buddy of mine tried it, and it ended up costing him tens of thousands in repairs, plus a full engine replacement. What's more, electrical components like spark plugs and sensors are prone to short circuits and rust from water exposure, increasing the risk of additional failures. The right approach is to avoid restarting the engine immediately after stalling—instead, call a tow truck to take it to a professional shop for inspection and drainage. Always keep an eye on water depth, making sure it doesn’t exceed half the wheel height, and drive slowly through puddles. Before the rainy season, check the sealing rings for any issues.

[LaVivienne]

Attempting a second ignition after driving through water is no joke—I learned this the hard way. That day, the water was a bit too deep, and my car stalled. I was about to try restarting it when a friend thankfully stopped me. If water enters the cylinders, it won’t compress during ignition, acting like a solid wall blocking piston movement. This can even bend or break the engine connecting rods, leading to repairs that cost a fortune, often upwards of tens of thousands. I’ve looked into it—this type of damage is called hydrostatic lock, involving direct tearing of the crankshaft and cylinder walls, far more severe than ordinary failures. Don’t just judge by appearances; water may linger in the chassis or air intake, doubling the risk if you recklessly attempt to restart. My advice? If the engine stalls, stop immediately and call your insurer or a dealership for a tow truck to avoid turning a minor issue into a disaster. For prevention, I avoid low-lying roads during the rainy season and always check the weather forecast before driving.

[NathanAnn]

Never attempt to restart the engine after driving through water. Let me share a painful lesson from my own experience. When water enters the engine cylinders, it's far less compressible than air. During ignition, the piston forcefully compresses the water, often resulting in bent connecting rods or even a cracked engine block - essentially writing off the engine. Not only are the repair costs astronomical, but it also compromises travel safety. Additional risks include short circuits in electronic systems from water intrusion, such as damaged oxygen sensors causing emission issues. The correct response is to turn off the engine immediately and call for a tow truck - never try to restart it yourself. In daily driving, I maintain low speed when crossing water to avoid creating large waves. Regular maintenance checks on air intake seals can prevent problems. Be especially cautious when water depth exceeds 30cm.