What are the long-term effects after repairing an engine that has taken in water?
4 Answers
After repairing an engine that has taken in water, the long-term effects are as follows: 1. Water immersion: If the vehicle was only immersed in water and then towed to a repair shop (without starting the engine), this generally does not cause irreversible damage to the engine. The main task is to clean the accumulated water inside the engine, but the extent of cleaning depends on the situation. More often, the intake pipe and intake manifold are removed, and compressed air is used to dry the water inside. In this case, there are usually no significant aftereffects. If you are concerned about aftereffects, you can replace all necessary parts. 2. A small amount of water entering the cylinders: In many cases, the owner is unaware that the engine has taken in water, and coincidentally, the amount of water is small (enough to allow the engine to start). If the owner chooses to continue driving at this point, the final consequence could be the piston seizing in the cylinder, with the connecting rod bending or breaking due to the immense pressure. A more severe scenario is the broken connecting rod piercing the cylinder block directly. At this stage, the engine may require major repairs or even be scrapped, and it might leave aftereffects such as shaking, reduced power, and frequent malfunctions. 3. A large amount of water entering the engine cylinders: This might seem the most severe, as the common belief is that more water causes more damage to the engine. However, in reality, when the cylinders are filled with a large amount of water, the engine crankshaft cannot rotate at all. Since water is incompressible, the piston has almost no room to move upward. At this point, even if the ignition switch is turned on, the starter motor cannot rotate, meaning no further damage is caused to the engine. Nevertheless, the engine will likely need major repairs at this stage.
Last summer, my car was flooded. After repairs, it ran smoothly, but a few months later, I noticed increased fuel consumption and reduced power. Upon disassembly, slight rust marks were found on the piston rings. It turned out that residual water had corroded the internal parts of the cylinder, accelerating wear and potentially clogging the oil passages, leading to insufficient lubrication. Since then, I check the engine oil and cooling system every six months to avoid additional towing expenses. For similar situations, it's essential to thoroughly clean all parts during repairs, including wiring harness connectors, otherwise residual water can cause electrical short circuits, and lights may burn out inexplicably. Now, driving feels much more reassuring. If you encounter water damage, never settle for superficial treatment.
After repairing a water-damaged engine, the most troublesome issue is rust spreading. This thing silently erodes metal components, and over several years, it may cause cylinder wall scratches or even engine seizure. I always recommend changing the oil and air filter during cleanup to ensure complete evaporation of moisture. Otherwise, residual muddy water can lead to a sharp increase in fuel consumption and abnormal noises. Remember to check the temperature gauge for signs of overheating before long-distance driving—this helps identify problems in time. For maintenance, frequently replace the coolant and inspect battery terminals to extend lifespan and save money.
Just spent 10,000 yuan repairing the water-damaged engine, thinking everything was fine, but when selling the car, the price was slashed in half due to buyers' concerns about potential future failure risks. Now driving it, I always feel sluggish acceleration, and fuel consumption is nearly 20% higher than usual, with each maintenance check costing hundreds. Water-damaged cars are prone to rust or electrical aging. After repairs, it's recommended to test drive short distances or install a diagnostic tool for real-time monitoring.
