2013 Jeep Grand CherokeeEnlarge Photo
Be suspicious of an interior that’s too clean
It should go without saying that if any part of the interior is wet, that’s a problem. Similarly, if you see mud or sand in the trunk, or on the carpet your job is done, and the car is likely a junker. Even without mud, the cardboard lining to which the headliner is attached could warp if it’s submerged. Look for anything that resembles an old textbook after a midnight coffee spill.
Many people consider a musky smell in the car to be another obvious sign, but modern detailing equipment can remove most odors. An odorless car isn’t the equivalent of a clean bill of health.
Instead, look for more subtle issues, like an interior that’s almost too clean. If the car was recently reupholstered, with a new headliner, carpet, or seat covers, it could be evidence of flood damage repair.
Go for a test drive
If everything checks out reasonably well, it’s time to go for a test drive. Listen for anything abnormal. A grinding noise from the brakes or steering, or a squeak over bumps might not be proof of a flood on its own, but if noises start coming from multiple places, it might be time to look for a different car.
Work your way up to carefully checking more advanced things like the anti-lock braking system, which relies on sensors that won’t work if their wires are corroded. The brake pedal should pulse against your foot and prevent the wheels from skidding if you operate an “emergency stop” by pressing hard on the brake pedal.
If you’re unsure at all, get a pre-purchase inspection
For a modest fee, nearly every mechanic or dealership will perform what's called a pre-purchase inspection, or PPI. Having one of these performed on any car, even one you're confident hasn't spent some time underwater, is generally a good idea.
A professional mechanic has access to a lift and can more easily check every nook and cranny of the car, front to back. He or she also knows how to spot potential problems much more easily than the average person. A good mechanic can look over the car in around an hour; think of the inspection fee as peace of mind.
If you can, look for a specialist—someone who works exclusively on that brand or similar models.
-- by Aaron Miller