How High Does Water Need to Submerge a Car for It to Be Considered Flood-Damaged?
2 Answers
If water submerges the exhaust pipe, the car is considered flood-damaged. Prolonged contact of water with components under the car body can easily cause short circuits or even fires. Although water-damaged vehicles can be repaired, serious hidden dangers may still remain after repair. Electronic System Failures: The most vulnerable parts of a car to water damage are the electronic systems. Although modern vehicles have waterproofing measures for electrical wiring, they cannot withstand heavy or prolonged submersion. If water remains in the engine compartment for an extended period, it can corrode wires and cause short circuits. In mild cases, electronic functions may fail, while severe cases can lead to spontaneous combustion. Engine Failures: Generally, if water has submerged the engine compartment, do not attempt to start the car. There is no guarantee that the engine is free of water, and starting it directly could cause the engine to fail completely. Transmission Failures: The main reason flood-damaged cars lose value lies in the transmission. Transmissions have vent holes to release pressure caused by temperature changes, usually located on the upper part. If water levels rise too high and submerge the engine compartment, water may enter the transmission. Once water gets inside, it can cause issues like slipping, shaking, or rough gear shifts. In severe cases, the transmission may require major repairs. Moldy Interiors: Rainwater contains many impurities, and a submerged car interior becomes an extremely humid environment, highly conducive to mold growth. If the vehicle is not dried promptly, mold can ruin fabric and leather surfaces and produce unpleasant odors.
The flood height of a water-damaged vehicle is a crucial indicator. Generally speaking, if the water level reaches the lower hub position of the wheels, there is potential risk. Based on my experience, if the water only reaches the hub height, it might just be minor water ingress, and clearing the drainage holes could solve the problem. If the water rises to the sill—the lower edge of the door—water may seep into the carpet or the interior of the sill, leading to rust or electrical short-circuit hazards. When the water level reaches the bottom of the seats, it indicates that water has entered the cabin, causing the seat foam to absorb moisture and mold, and potentially affecting the air conditioning and electronic control systems. More severe is when the water rises above the dashboard height, as almost the entire engine bay and control computers could be damaged, resulting in high repair costs and safety risks. I remember a friend’s car was flooded up to the seat level, and afterward, the air conditioning always had a foul odor—even after expensive repairs, it was never fully fixed. So don’t take it lightly; if the water exceeds the hub height, get it checked at a professional shop, and avoid parking in low-lying areas.
