Back after Katrina, the used car market was filled with ‘Katrina cars’ that were written off but then resold, often plagued with long-term electrical issues.
There weren’t many EVs back then, so I’m wondering—how would an EV handle flooding now? My guess is that they’d short out hard and be unresellable, but could an EV keep working and still have long-term issues, like waterlogged ICE vehicles used to?
Is this something people buying used EVs should look out for, or probably not? Thanks for reading.
I suspect EVs would have similar long-term issues to ICE vehicles after flooding, especially when it comes to electrical systems, plus the added concern of high-voltage components.
zendaya said:
I suspect EVs would have similar long-term issues to ICE vehicles after flooding, especially when it comes to electrical systems, plus the added concern of high-voltage components.
Exactly. Flood damage usually messes with wiring and electronics, not so much the engine itself, whether it’s an ICE or an EV. Modern cars have tons of sensors and electrical components that are susceptible to corrosion, and water can creep into places it shouldn’t.
What usually kills a car after flooding is water getting into the computer systems. Once the computers are fried, there’s no bringing them back. While you can tear out the interior and dry it, the electronics are much harder to salvage.
And forget it if it’s saltwater—that destroys everything. Freshwater might be a bit more forgiving, but still risky.
@kwame
That ‘fresh’ water is probably not so fresh after flooding. If I had a flooded car, I’d tear it down immediately and wash everything with distilled water, but I’d still expect some parts to fail. That car would never be resold.
@Imani
If the water rises above the bottom of the doors and fills the car, it’s pretty much toast. A few inches on the floor? Maybe salvageable if it’s not too dirty.
kwame said: @Imani
If the water rises above the bottom of the doors and fills the car, it’s pretty much toast. A few inches on the floor? Maybe salvageable if it’s not too dirty.
Where I live in Illinois, even minor flooding can total a car by law.
The real problem with flooded cars is wiring. Every electrical connection in a car is gasketed to keep out splashes, but floodwaters exert pressure, and even a small amount of water can push past those gaskets. Once water gets in, it corrodes the contacts, and the gaskets do a great job of keeping the water in there to make sure the damage continues.
Electronics can also be wrecked if they aren’t well-protected or potted (coated in epoxy). Even if your engine or battery survives, you’re looking at endless electrical issues with the wiring harness, which is expensive to replace.
It’s not just an ICE problem. If I had a flooded EV, I’d deconstruct the car and inspect everything, but honestly, stripping it for parts might be the best move.
Stay away from flooded cars for sure. A tip I’ve heard: bring a white cotton glove when looking at a used car. Reach under the seats and rub the metal support. If you see rust on the glove, the car was probably flooded.
Even though the high-voltage (HV) components are sealed and protected, the low-voltage (LV) system (like the cabin electronics and ADAS) is just as vulnerable as it would be in an ICE vehicle.
So with a flooded EV, one of two things will happen:
The HV components are damaged and the car doesn’t work at all, making it unsellable.
The car drives but the soaked LV components will cause endless problems later on. Once the 12v system goes, the car can’t even charge properly.
I talked to a Rivian tech who mentioned that their trucks are sealed to ford up to 3 feet of water, which is better than most EVs. There’s a video of a Rivian that survived a flood—water went over the hood, but the truck was still drivable. So maybe Rivians have a better chance in a flood than other EVs, but I wouldn’t leave it sitting in water for days.
Floodwater—especially saltwater or sewage—can mess with any car, but EV battery packs are usually sealed pretty well. That said, the interiors, door fittings, and low-voltage components might still take damage. It’s definitely something to consider when buying a used EV, just like with ICE vehicles.