Why Does Water Enter a Car Engine?

[DelNicole]

There are several reasons why water may enter a car engine: 1. Damaged cylinder liner sealing ring: The sealing ring at the lower part of the cylinder liner is designed to prevent the leakage of engine oil and coolant. However, under prolonged pressure, aging of the sealing ring is inevitable. If the coolant is of poor quality, it may also have a corrosive effect, leading to leakage into the engine oil. 2. Damaged cylinder head gasket: The engine cylinder head gasket serves to seal the water passages and oil channels between the cylinders. If the cylinder head gasket becomes damaged or aged, water from the water passages may flow into the oil channels, causing water to enter the engine. 3. Damaged oil cooler: If the oil cooler is damaged and its pipes break, external water from the cooler may seep inside, resulting in water entering the engine.

[AngelinaLee]

Last time during the heavy rain, I saw several water-damaged cars at the repair shop, mostly caused by drivers forcing their way through flooded areas. The engine air intake is right behind the grille—if the water level exceeds half the tire height and you still step on the gas, water gets directly sucked into the intake pipe. Some cars parked under trees for long periods had their windshield lower-edge drainage holes clogged by leaves, causing rainwater to accumulate in the engine bay and soak the ignition coils. The most unfortunate case was a modified car whose owner added cooling vents on the hood but skipped waterproofing—a high-pressure car wash spray fried the ECU instantly. Repairs for these range from thousands to even engine replacement. Before driving in the rainy season, always check the weather forecast and avoid flooded areas.

[KimberlyMarie]

My neighbor's sister's BMW had its engine flooded and needed a major overhaul, and the reason is particularly infuriating. The drainage pump in her underground garage broke, and no one fixed it. During a heavy rainstorm, water backed up and submerged half of the tires, leaving the car soaked for two hours before it was discovered. Also, be careful when washing your car. Some roadside car wash workers cut corners by recklessly spraying high-pressure water into the engine bay. Water seeping into the ignition coil connectors and causing a short circuit is the most troublesome issue. If you notice white smoke coming from the exhaust pipe or the engine oil turning milky white, shut off the engine immediately and call for a tow truck. Never attempt to restart the engine, or you could end up bending the connecting rods—repair costs could be high enough to buy a used commuter car.

[DeDante]

Off-road enthusiasts must have learned their lessons. I once got into trouble when crossing a river in a Jeep. The waves created by the current were much deeper than expected, and the water pushed up by the front of the vehicle directly flooded the air intake. Later, an experienced mechanic taught me: when installing a snorkel on a 4WD vehicle, pay attention to the sealing of the pipes. For older vehicles, remember to replace the valve cover gasket, as mixed oil and water due to aged rubber can damage the engine more. Friends in the north should also beware of road salt in winter, as it corrodes chassis components and allows snowmelt to seep into the transmission vent pipe. I've seen an Audi Q7 undergo major transmission repairs because of this.