Why Shouldn't You Attempt to Restart the Engine After Water Ingestion?
4 Answers
Because restarting the engine can cause damage, and insurance companies will not cover the costs if you do so. Here are the relevant explanations: 1. Driving Through Water: If water is sucked into the cylinders while driving through water, it can cause the engine to stall. Forcing the starter to crank the engine in this situation will make the pistons attempt to compress the water. Since water is incompressible, the result is often damage to the engine's connecting rods and crankshaft, requiring extensive engine disassembly for repairs. 2. Stalling in Water: In many cases when a car stalls while driving through water, it's not due to water entering the engine but rather the increased resistance from the water causing insufficient engine power and stalling. To check if water has entered the engine, simply open the air filter cover and inspect whether the filter is wet. If the filter is soaked, there's a high chance water has already entered the engine.
That time I was driving in a heavy rain and unfortunately stalled while wading through water. I almost tried to restart the engine, but luckily my friend reminded me just in time to avoid a disaster. After wading, if water enters the engine and you attempt to restart it, the water can be sucked into the cylinders. Unlike air, water cannot be compressed, so when the piston moves upward, it will face enormous pressure, potentially bending the connecting rods or even shattering the cylinder block, completely destroying the entire engine. I've seen many cases where repairs cost tens of thousands, or even led to the car being written off. Before wading, always slow down and maintain a steady speed to avoid splashing water into the engine. If the engine stalls, never touch the ignition key—just call a tow truck to take it to a repair shop, or at least confirm that no water has entered the intake before doing anything. Always pay attention to your car's wading depth—safety first saves both peace of mind and money!
As a mechanical enthusiast, I must say that engines operate by igniting compressed air. After wading through water, the intake is prone to water ingress. If you attempt to restart the engine, the water in the cylinders cannot be compressed, causing significant resistance to piston movement, which can easily lead to bending or cracking, instantly damaging core components. The repair cost for such mechanical failures is high, potentially reaching tens of thousands of dollars—sometimes it's better to just buy a new engine. Water intrusion can also corrode electronic components, triggering a chain of issues. When driving through water, use a low gear to pass steadily; if the engine stalls, don’t act impulsively—check for water leakage in the engine. Understanding these principles has helped me develop good habits and avoid unnecessary losses.
Never attempt to restart the engine after stalling in water! Igniting in water can total your engine—for example, if water enters the cylinders, the inability to compress it may damage pistons or connecting rods, with repair costs starting at thousands. I always advise friends: it’s safer to push the car or call for roadside assistance. If the water depth doesn’t exceed half the tire height, you may proceed cautiously; otherwise, take a detour. Afterwards, clean water stains from the undercarriage to prevent corrosion of electronic components. Taking these simple steps can protect your car.
