With Sandy being a wet, windy jerk to most of the Northeast, we've been seeing lots and lots of pictures of flooded streets, underground parking lots turned into dark auto-aquariums, and generally many, many cars being submerged in way too much water. Water, like its nemesis fire, is a good servant but a cruel master, and there's little that can be more damaging to a car than a really good soaking. So, if you're one of the countless numbers of unlucky folks who are now the owners of a 2500 lb coral reef, is there anything you can do? Is there any way to salvage your car after it's spent any amount of time underwater? And, if so, is it worth it?
The odds aren't great for recovering a drowned car, but it certainly can be done. We'll walk through the widely-agreed upon steps to try and help salvage your dampened ride.
This assumes it’s worth it to you, in most cases your insurance agent will just pay to scrap it.
Don't turn anything on!
When you finally find your car after the floodwaters have receded, you may very well be tempted to put the key in and see what happens. Don't. Every part of the car has been soaking in water, and there's water in pretty much every place water shouldn't be. If you even put the key in that could start electricity flowing through water-logged connections and wires, and since water conducts, that means shorts and major electrical damage. If you have power locks, don't use them— try and do everything manually. Hopefully, your battery was ruined first and no current was flowing through the car. If at all possible, get the hood (or trunk, or lift the back seat, etc) open and get to the battery, and disconnect the ground strap first thing. While its wet, we want no electrons moving through any of the car.
Figure out how bad it is
If you don't think the car was entirely submerged, you'll want to figure out just how much it was, so look for a high water line. If it's roughly below the dashboard area, you probably got lucky, as it's likely your car's electronics were spared.
Drain everything you can drain
Your car has many parallel fluid systems— oil, fuel, hydraulic fluid, transmission fluid, and even water, and chances are really good unwanted water is in all these systems. Check any and all dipsticks for water droplets so you can get an idea how bad things are. If you see droplets of water on the dipstick, it's bad. So, drain the fuel system (you may need or want to remove the gas tank to drain), drain all the oil from the crankcase—if possible, it's not a bad idea to remove the oil pan and let any water drip out — same goes for the transmission, if you're able. If you can replace the brake fluid (and hydraulic clutch fluid, if applicable) do it. Change out spark plugs, air, fuel, and oil filters, anything that may have gotten water in it.
For all this, I'm assuming and hoping the car was off when flooded— a running car submerged is a different story, as electrical systems will short and the engine may actually take water into the cylinders, which can cause a great deal of damage. Let's hope that's not your car.
Be happy you drive an older car/wish you drove an older car
If you drive a carbureted car from, oh, the 70s or earlier, your chances of recovery success are much higher, simply because these older cars just don't have the complex and somewhat delicate modern electronics of newer, fuel-injected cars. Earlier car electrical systems are generally much simpler in general, and have much larger and looser tolerances for connectors, wiring, and other water-sensitive parts.
Let the electronics dry as best you can. Maybe try some rice.
This is by far the trickiest part. Almost every remotely modern car is controlled by a number of cooperating computer units, and these computers communicate via low voltage signals and data streams and have tiny connectors that are sensitive to corrosion, or may trap little pockets of moisture that could cause shorts and possibly fry your expensive ECUs. There's a number of ways to do this, but one way I haven't yet heard mentioned but I feel may be worth trying is the rice method. I've known people to place submerged iPhones in bags of rice for a few days, and the rice does a remarkably good job of absorbing the moisture from the phone. I think a similar system could work for your car's electronics, if you can find where things are and can get rice nearby. This is a big if.
If you can remove ECUs or dash units or even radio head units, it may be worth packing those components in a Tupperware-type plastic box with a bunch of rice, and leaving it for a few days. It certainly can't hurt. The more water you can draw out of these units the better.
The stink. Oh god, the stink.
Chances are your car wasn't flooded with the purest mountain spring water or rosewater or Scope; it's much more likely it was disgusting, muddy, partially sewer-tainted yuck-juice. All the soft, porous bits in your car have absorbed all this grossness, and there's not a hell of a lot you can do. You can let it dry, and help the process with hair dryers or similar, but it's very likely the seat fabric, stuffing, and carpet will retain some sort of olfactory record of the disgusting. Harder, nonporous plastics will fare better.
Try cleaning with conventional methods anything you can. It may not do much for residual smells, but it can't hurt. Maybe cultivate an interest in other smelly things you can use to mask the scent— now could be the time for that dashboard herb garden, or possibly the center-console artisan cheese display case you've been considering.
The only solution here may be to rip everything soft out— carpet seats, etc, and replace them with new or used materials, or go racecar style and try a carpet-less car for a while. You may find you like it!
If you get this far, and have drained and replaced everything, dried your electronics, it's time to give it a try. With any luck, your car has been resurrected from the screaming moist, and now you and your mechanical pal need to celebrate with a drive. Getting things running and moving should help flush out any remaining water from the system. Expect rough driving and losses of power as water works its way out of fuel lines and the engine in general. But don't give up— heat, lubricating oil, and the action of the engine will all help your car to recover. Run the heater and a/c, and get ready for some disgusting water to spray out of the vents, and likely some rich, complex odors as well. Drive with the windows down.
Don't give up. You're dampened, but unbowed. And think of the great story you'll have to tell about your car!