Drying Out Your Flooded Car

By Mike Allen, PopularMechanics.com

We’ve all seen it on TV: rainstorms of biblical proportions sweeping entire villages into the sea, and damp, devastated flood victims being interviewed in front of a pile of sodden furnishings and clothing. But then it happens closer to home–only this time it’s your car, not the entire village. There’s a high-water line halfway up the windshield, and several inches of mud in the interior and the trunk. It smells like a swamp, and it’s only getting worse in the hot sun. And the insurance adjuster says he’ll be by in a few days.


Don’t wait for the adjuster to arrive. Mold and corrosion are setting in now. You need to clean out as much liquid and mud as you can and dry out your car as soon as possible. Don’t try to start the car. If there’s water in the engine, transmission or fuel system, you’ll just compound the damage.

Disconnect the battery ground strap first-you must do this, otherwise you’ll fry something.

Next, begin assessing just how deep the water got. Frankly, if the waterline is as high as the dashboard, you will probably be better off talking the adjuster into totaling the car and getting another. Double that for salt water. The mechanical systems and the interior can be dried out or cleaned with a lot of labor, but the electrical systems on modern cars are extremely complex. These systems rely on a lot of low-voltage signals from sensors in the engine management system and ABS. These low-voltage signals are extremely sensitive to corrosion on connectors, and problems can crop up for years.

Look for a high-water mark. That can be easy–if the water was muddy or there was a lot of floating grass and leaves. But clean water may leave no residue. Look for water inside the doors and the taillights, and dampness in the carpets and interior trim. This will allow you to eliminate cleaning some areas or systems on the car unnecessarily. Let’s go through those systems.


Check the dipsticks for the engine and transmission. If there are water droplets clinging to the end of either dipstick, you absolutely, positively need to change the oil and filter before even thinking about starting the engine. If the water was muddy, it’s probably wisest to remove the oil pan from the engine and wash the mud out. Change the oil and filter again in a few hundred miles, too.

Late-model cars have sealed fuel systems, and probably won’t get any water in them. But that classic ’55 T-Bird probably ingested some water if it was deep enough and lingered long enough. Siphon the fuel out into a container and look for water. If you find any, it’s probably best to drop the tank and get it cleaned professionally. Blow out the fuel line, and you may need to get water out of the carburetor float bowls as well. If you find evidence of water in a fuel-injected car or truck’s tank, replace the fuel filter as well. That paper element will disintegrate if it gets waterlogged. It’s not that a few drops of clean water are bad, but floodwater is usually pretty foul with silt and sludge.

Muddy water can infiltrate its way past engine seals within a few hours. Crankshaft seals, transmission seals and axle and CV joint seals are adequate to keep lubricants in, but they are not designed to keep standing water from creeping in. Before you start the engine, or tow a car with the wheels on the ground, drain and change the oil, transmission fluid and final-drive lube. Check the dipstick for water droplets. And don’t forget wheel bearings and constant velocity joints, which will need to be cleaned and repacked. Some front-drive cars have sealed-for-life front axle bearings, and you’ll simply have to wait for those to fail, because it’s nearly impossible to clean and relube them.

And then change those fluids again in a thousand miles or so if there was evidence of muddy water.


As incredible as it may seem, it’s possible for a dealer or an individual to acquire, legally, a title for a car that’s been flood-damaged and totaled that doesn’t reflect the damage. In most states, totaled cars’ titles bear a salvage tag on the title. But a dealer can wholesale the car out to a state that issues the fresh title without tagging the car as salvage. Which states? It doesn’t matter because once the title has been laundered, it can be retitled in any state, clean as a whistle. And I’d rather not say, so nobody gets any ideas about laundering the title to a damaged car.

So caveat emptor (let the buyer beware). Always examine any potential used car or truck purchases with a jaundiced eye. Look carefully for evidence that the vehicle has been wet: i.e., mud in unusual places in the trunk, water marks inside the instruments, an owner’s manual that looks like it’s been wet, warped fiberboard door panels or glovebox interiors.

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