What is the impact of successfully restarting the engine after stalling in water?
2 Answers
Restarting the engine after stalling in water can damage the engine. Relevant explanations are as follows: 1. Do not attempt to restart: Once the vehicle stalls in water, you must not attempt to restart it. Since you are in heavy rain or a flooded condition, it is impossible to determine the exact cause of the stall. Therefore, the most reliable approach is to avoid attempting to start the engine again. 2. Connecting rod fracture and ejection: After the vehicle is submerged in water, water enters the cylinders through the intake manifold. Due to the incompressibility of water, the piston's stroke will shorten, leading to bending or fracture of the engine connecting rods. Under extreme conditions, the fractured connecting rod can be ejected and penetrate the engine block.
I've repaired many cars like this before. Successfully restarting after stalling in water actually carries significant hidden dangers. Although the engine may start at the time, water could have already entered, which can lead to a wet air filter and subsequently cause water ingress into the crankcase. In the short term, the car might still run, but potential damages include bent connecting rods, worn piston rings, and even internal engine rust. Over time, the repair costs can be substantial, possibly requiring an engine overhaul and replacement of multiple components like cylinder heads. I recommend immediately checking the oil dipstick for any water traces and, ideally, taking it to a professional shop for water drainage and drying treatment to prevent minor damages from accumulating into major failures. When driving through water, always measure the depth first—if it exceeds half the wheel hub height, don't force your way through. Otherwise, the gains won't outweigh the losses. Safety should always come first.
