What Happens to Cars That Drive Through Flooded Roadways? It’s An Expensive Gamble

LAFAYETTE, La. (KPEL News) -- We got a lot of rain here in Acadiana yesterday. Yesterday's deluge saw major roadways in Lafayette turn into rivers. Ambassador Caffery Parkway was closed for several hours yesterday, leaving dozens of cars stranded after they attempted to drive through the high water. Driving through floodwaters poses significant risks to both vehicle integrity and occupant safety. Even shallow water can lead to severe mechanical and electrical damage, resulting in costly repairs or total vehicle loss.

Engine Damage

When a vehicle traverses deep water, there's a risk of water entering the engine's air intake system. This can lead to a condition known as hydrolock, where water fills the engine cylinders, preventing pistons from moving. As a result, the engine may stall and sustain irreversible damage. According to Family Handyman, "If water enters the engine it can lead to bad things... Piston rods will begin to bend and eventually break."

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Repairing or replacing a hydrolocked engine can be prohibitively expensive, often ranging from $3,000 to $8,000, depending on the vehicle's make and model.

Transmission and Differential Damage

Submerging a vehicle can allow water to infiltrate the transmission and differentials. Water contamination dilutes lubricants, leading to increased friction, overheating, and eventual failure of these components. Repairing or replacing a transmission can cost between $1,000 and $4,000, while differential repairs may add several hundred dollars to the total expense.

Electrical System Complications

Modern vehicles rely heavily on complex electrical systems. Exposure to water can cause short circuits, corrosion, and failure of critical components such as the alternator, starter motor, and onboard computers. The Dangers of Driving on Flooded Streets article by Consumer Reports notes, "Floodwater can destroy a car’s engine and wreak havoc on electronics."

Repairing or replacing damaged electrical systems can range from a few hundred to several thousand dollars, depending on the extent of the damage.

Brake System Issues

Driving through water can compromise the braking system. Wet brakes may lose effectiveness, and prolonged exposure can lead to rust and corrosion of brake components. Family Handyman advises, "Check your brakes — wet brakes typically lose their grip."

Brake repairs can vary from $300 to $800, depending on the vehicle and the extent of the damage.

Interior and Upholstery Damage

Floodwaters often carry contaminants that can damage a vehicle's interior. Seats, carpeting, and insulation can become saturated, leading to mold growth and unpleasant odors. State Farm recommends, "Remove all moisture... use a wet/dry vacuum to collect standing water in your vehicle."

Restoring a vehicle's interior can cost between $1,000 and $2,000, depending on the materials and labor required.

Insurance Considerations

Comprehensive auto insurance policies typically cover flood damage. However, if repair costs exceed the vehicle's value, insurers may declare it a total loss. Consumer Reports states, "You may have a strong emotional connection to your car, but if it has been in a flood, it might be too expensive to repair."

Preventive Measures

To avoid these costly repairs, it's crucial to heed flood warnings and avoid driving through standing water. The National Weather Service advises, "Turn Around, Don't Drown," emphasizing the importance of not attempting to cross flooded roads.

The bottom line...driving through floodwaters can lead to extensive vehicle damage, with repair costs potentially exceeding the vehicle's value. Avoiding flooded areas and understanding the risks can prevent significant financial and safety consequences.