Flood damage is expensive to repair, so vehicles that have been flooded are often totaled by their insurance companies. Many will then be repaired and resold. Such vehicles should be identified as such on their title but some less scrupulous sellers avoid this. That’s because flood damage takes a big bite out of the value of a car. Quite simply, most car buyers don’t want a vehicle that’s been immersed in dirty water, and for very good reason.
There are three scenarios to consider. Think of them as Bad, Worse, and Dreadful. Bad is when the water rises around a parked car. It gets into the passenger compartment, soaking carpets, seats, and electronics. It fills the engine bay, diluting or washing away lubricating oils and replacing them with dirt and grit. And it can get into the braking system, fuel tank, and fuel lines.
Worse is when the vehicle was driven into floodwater. This happens a lot with flooded underpasses. The driver plows through what looks like a few inches of water, only to find that it’s much deeper. Water gets drawn through the intake system and into the engine. Unlike the fuel and air mixture the engine expects, water is incompressible, so as the pistons rise in flooded cylinders the engine locks solid, often sustaining severe damage in the process.
Dreadful is when the flooding is from seawater. While the immediate damage is the same as for river or rainwater, saltwater is far more corrosive and the long-term consequences even more destructive.