How to spot a flooded second-hand car

A buyer's guide for the typhoon season


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(Alaska Department of Transportation and Public Facilities via AP)

The typhoon season in the Philippines brings torrential rains and inevitable floods, leaving not only damaged homes but also flood-damaged vehicles in its wake. These vehicles often find their way to the second-hand car market, where unsuspecting buyers might unknowingly purchase a car that has been submerged in water. A flood-damaged car can result in countless mechanical and electrical problems down the line. Thankfully, with some simple tips from experts, you can avoid making a costly mistake.

I spoke with Alex Lao, who has been in the automobile service business for over 2 decades, about pointing out tell-tale signs of flooding. Alex has seen his fair share of flood-damaged vehicles, and here are his expert tips on how to spot a flooded second-hand car on the market.

Water marks and mud remnants

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Floodwater, especially muddy or dirty water, often leaves telltale signs in hard-to-reach areas. While sellers may clean visible parts, they often overlook the nooks and crannies where mud and silt can accumulate. As Alex Lao explains, check inside door frames, the trunk, and under the seats for any mud marks or discolored spots. These are signs that the car may have been submerged in floodwater. Mud often gets stuck in corners or hidden spots, and a thorough inspection of these areas could reveal leftover dirt or stains that indicate water damage.

Unusual smells inside the car

A musty, moldy odor is another red flag that a car may have been flooded. Water can seep into the car's interior, soaking the fabric, carpets, and seats, which leads to moisture buildup and eventually mold. According to Alex, sellers might try to mask these smells with air fresheners, but the scent of mildew or dampness will still be noticeable. He advises lifting the carpets and checking the underlying material for any signs of moisture. If the area feels damp or smells foul, it's likely that the car has been exposed to water.

Inspect electrical components

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Floods can seriously damage a car's electrical system, and even if the seller cleans up the vehicle's exterior, electrical issues might still be lurking. Lao suggests closely inspecting electrical connections, especially under the dashboard, inside the engine bay, and behind headlights. Corrosion or rust on these components can be a sign of water exposure. Additionally, test all the car's electronic features—headlights, windshield wipers, and air conditioning—to ensure they are functioning correctly. If anything seems erratic or malfunctioning, it could indicate underlying water damage.

Check for moisture in headlights and fog lamps

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One often overlooked indicator of flood damage is condensation or water marks inside the headlights, fog lamps, or taillights. Alex highlights that if you notice any misting or trapped water inside these components, it's a clear sign that the vehicle has been exposed to water. Even if the exterior of the car looks pristine, moisture inside the lighting components is a strong indicator of past flood damage. Be sure to carefully inspect these areas when assessing a potential purchase.

Rust in uncommon places

While older cars might have some rust in expected areas like the undercarriage, flood-damaged vehicles tend to rust in more unusual places. This includes metal parts inside the cabin, such as seat brackets, or under the dashboard. According to Lao, check the springs, levers, bolts, and other metal parts beneath the seats and dash for signs of rust. If these typically protected areas show signs of corrosion, it's a clear indication that the car has been exposed to water.

Engine oil and transmission fluid

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A helpful trick to identify a flooded car is by inspecting the engine oil and transmission fluid. If water has mixed with the oil, it will create a milky or mocha-colored residue. While sellers often change the oil to hide this, Alex Lao advises draining a small amount from the engine or transmission oil pans to check for water. "Just because there's no water on the dipstick doesn't mean the engine's clean," Lao notes. Draining a little oil will help you identify if water has settled in the oil pans, which could indicate the vehicle was submerged.

Listen for sloshing sounds

Lastly, Lao suggests listening for sloshing sounds when you accelerate or brake. Sometimes, water gets trapped in the door panels or running boards, and this can cause a distinct sound as the water moves around. While this isn't always conclusive proof, combined with other signs, it can indicate water damage.

Buying a second-hand car during the typhoon season requires extra caution, especially with the risk of flood-damaged vehicles making their way into the market. While some sellers might do their best to clean and hide signs of water damage, these tips from Alex Lao will help you spot potential red flags. Remember, a flood-damaged vehicle is not just a financial risk—it can be a safety hazard as well. Always inspect thoroughly, and when in doubt, consult a professional mechanic before making your purchase.