Table of contents
Why you shouldn’t buy a flood-damaged car6 Levels of Damage from Flooding10 tips for identifying flood-damaged used carsBe wary of used cars priced below market valueUsed parts could come from flood-damaged vehiclesWhat to do if you bought a flood-damaged car or your vehicle has been floodedSelf-rescue techniques when flooding occurs while drivingAre Tesla cars really immune to flood damage?
【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

10 tips to identify flood-damaged cars & surviving a flood

In September 2023, Hong Kong experienced a once-in-500-years catastrophic event resembling scenes from a disaster movie. Severe flooding occurred in many areas, with some roads, shopping malls, and parking lots completely flooded. Many vehicles were damaged to varying degrees by the floodwaters. Concerns arose about these flood-damaged cars entering the used car market after repairs, potentially compromising road safety. For many used car buyers, telling whether a vehicle has been previously flooded based solely on its appearance is no easy task. Kwiksure here shares 10 tips for identifying flood-damaged used cars and offers ways to self-rescue and repair vehicles that have been flooded to varying degrees.

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

Why you shouldn’t buy a flood-damaged car

A car comprises mechanical and electronic components, plastic, leather, and other materials. Apart from the vehicle body and certain external mechanical parts, most components lack waterproof capabilities. Flooding can significantly shorten the useful life of a vehicle and also have an impact on the following parts:

Metal parts

Metal parts will be more prone to rusting, affecting the overall rigidity of the car. In a crash, more serious damage can result, possibly putting the driver and passengers at risk.


The engine is a precision machine. Once it has been flooded, it becomes prone to ignition timing errors, significantly increasing the chances of malfunctions.

Electrical parts

This refers to all the electronic components in the vehicle, including the electronic devices inside the cabin and the plugs in the engine. If they have been flooded, it can result in anything from short circuits to the vehicle itself catching fire, leading to potentially serious consequences.

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

6 Levels of Damage from Flooding

Level of damage Seriousness of flood Estimated extent of damage
Level 1 The water level reaches the vehicle chassis, but the cabin has not had a significant water ingress The carpet
Level 2 The water level reaches halfway up the wheels, and water starts to enter the cabin Power components of seats, components under the center console
Level 3 The water completely submerges the tires, reaching the driver's calves The entire center console, along with most electronic components inside the cabin
Level 4 The water level approaches the top of the engine, reaching the driver's waist Car light assemblies, engine air intake components
Level 5 The water completely submerges the hood, reaching the driver's chest All electronic components and mechanical parts, plus the air conditioning system
Level 6 The vehicle is fully submerged in water The sunroof and top part of the cabin

10 tips for identifying flood-damaged used cars

Most of the used cars for sale have been refurbished or cleaned before becoming available in the second-hand market. However, there are still telltale signs that can reveal a flood-damaged vehicle. Don't want to end up with a lemon? The 10 tips below will help you identify flood-damaged used cars! Remember that it's best to inspect a vehicle in a well-lit area and ask a friend who knows cars to lend a hand.

1. The carpet

After being submerged in water, carpets are likely to develop a musty odor. Even after exposure to intense sunlight, this odor still may not completely go away. Unscrupulous sellers often use huge amounts of perfume to mask this weird smell, and buyers should be aware of this. Moreover, you can gently press down on the carpet. Since both the carpet and the soundproofing material underneath are made of sponge, if they have been waterlogged, the sponge's elasticity will be affected.

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

2. Rubber part interfaces

Open the doors and inspect the rubber parts near the door sills that connect to the vehicle floor. If you notice any pry marks or misalignment, chances are that the soundproofing materials beneath the floor had had to be cleaned.

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

3. Rubber edges on the entire vehicle

Due to the presence of large amounts of leaves and mud during flooding, it is possible for them to accumulate within the rubber edges. Moreover, sellers may not clean these areas. Therefore, buyers can peel back the rubber edges of the doors, tailgate, and engine bay to check for any traces of mud or debris.

4. Seat belts

Seat belts are mostly made of nylon in a high-density weaving process. Seat belts that have been through a flood may have a darker color. Buyers can pull out the entire seat belt and check for any two-tone appearance. It is also important to carefully inspect the underside of seat belts for signs of mold.

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

5. Fuses

The fuse box is usually located below the steering wheel or in the engine bay. Buyers can open the fuse box and take out the fuses to check for signs of oxidation. If oxidation is found, the vehicle may have been submerged in water, which can lead to short circuits or even fires in electronic components. This poses a significant danger.

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

6. Cigarette lighter

If the cigarette lighter has been submerged in water, the buyer may not clean off the water stains right away. As a result, after some time, the cigarette lighter may show signs of rusting.

7. Electrical components

Flood-damaged vehicles are more prone to short circuits. You can test the various electrical components inside the car, such as the car stereo, fan, and USB ports, to check if they are functioning properly. Also, watch out for the presence of unusual smells.

8. Engine bay

The inner wall of the engine bay near the cabin is usually lined with fireproof sound insulation material. Buyers can visually inspect if the color appears different and gently press it with their fingers to check if it feels dry, firm, and elastic. Also, carefully inspect the plugs, wires, and air deflectors for signs of mud stains or water stains.

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

9. Seat Rails

Water is the biggest enemy of metal, especially for metal components inside the car that have not been rust-proofed, such as the rails beneath the seats. After being submerged in water, they are prone to rusting. You can simply adjust the seat position to inspect the rails. If the seats are power-adjustable, you can also check if the seat motors have been damaged by water.

10. Spare tire

The spare tire is typically placed at the bottom of the trunk at the back of the vehicle. It is often covered by a lid and is less frequently accessed. Moreover, its concave shape makes it prone to water accumulation. When inspecting the vehicle, you can remove the spare tire and carefully inspect its surroundings for signs of water damage.


Be wary of used cars priced below market value

Due to the compromised performance of flood-damaged vehicles, owners are often eager to sell them, resulting in lower prices. When purchasing a used carif you come across a significantly lower price than the market value, you should be extra cautious and carefully examine the vehicle's source and inspect its physical condition.

Comparing the quotes from over 60 HK insurers, Kwiksure helps you choose the car insurance that best fits your requirements. Get a quote now!

Used parts could come from flood-damaged vehicles

In addition to being cautious when buying a used car to avoid purchasing a flood-damaged vehicle, you should be aware that, due to the high cost of repairs, unscrupulous dealers may remove parts from flood-damaged cars and sell them in the used parts market. However, inspecting used parts for water damage can be challenging. Therefore, it is recommended that you avoid purchasing used parts for critical vehicle components, such as the engine or electrical components, for some time in the aftermath of extreme weather conditions.

What to do if you bought a flood-damaged car or your vehicle has been flooded

If you unfortunately purchased a flood-damaged car, due to its compromised performance, you may become the cause of an accident. If a traffic accident occurs due to fault on your part, your losses may not be covered. Therefore, it is advisable for car owners to thoroughly inspect the vehicle when purchasing a used car. For more details, please refer to our tips for self-inspecting a used car.

If your vehicle has been submerged in water while parked, it should be checked only after the water has receded. Remember not to start the engine and disconnect the battery terminals in the engine bay. Next, check if the air deflector is wet. If it is dry, you can reconnect the power and start the engine. If it starts successfully, drive the vehicle to a sunny place to let it dry, and then have it thoroughly inspected by a professional garage to prevent any potential issues with the electrical system due to water damage.

Self-rescue techniques when flooding occurs while driving

If flooding occurs while driving, the first order of business is to stay calm. Check if there are alternative routes to drive the vehicle away from the water or to a higher ground until the water recedes. If you must drive through the water, estimate the depth of the water first. If the water is only up to half of the wheels, you can keep pressing the gas pedal gently and drive slowly in a low gear. During this time, do not release the gas pedal, as this could allow water to enter the exhaust pipe and damage the engine.

Are Tesla cars really immune to flood damage?

【極端天氣過後】10 招分辨水浸二手車 |附車輛水浸自救術

Although Tesla and other electric vehicles do not have an engine, eliminating concerns about water entering the exhaust pipe, and their electrical systems and high-voltage batteries use sealed enclosures, that doesn’t mean that you can safely drive a Tesla into a flooded area. There are online videos of tests conducted in mainland China, showing that it is safe to drive a Tesla through water up to half the height of the wheels. If the water depth exceeds half the wheels’ height, water can possibly enter the high-voltage battery and cause damage.


Contact Kwiksure to get motor insurance quotes

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The above information is for reference only. Kwiksure takes no responsibility for the accuracy and timeliness of the information. For the coverage, mode of compensation, benefit limit and premium levels of any specific insurance plan, please refer to the relevant policy terms.
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Author Kwiksure Team

Kwiksure is a licensed motor insurance brokerage company with over 20 years of experience in insurance. The company strives to simplify insurance and select the best insurance plans for customers that fit their budget and coverage needs.

Kwiksure provides a range of insurance products, including car insurance, motorcycle insurance, cross-border insurance between Hong Kong and Mainland China, home insurance, travel insurance, domestic helper insurance, and voluntary medical insurance. The team has been named "Best Car Insurance Broker" and "Outstanding Leadership Award" by various media outlets over the years.