How to avoid buying a flood-damaged car: 10 checks and warning signs

Floodwater leaves its worst damage where a shopper rarely looks. A car pulled from a flood can be shampooed, detailed and parked on a lot looking no different from its neighbors. The damage can still sit in its upholstery, its wiring and even its paperwork.

That damage tends to fall into three areas. The first is the cabin. Soaked carpets and seats are hard to dry out fully, and a car left damp can grow mold. Edmunds describes black mold as extremely dangerous.

The second is the electrical system. An owner caught in a flood probably had no chance to disconnect the battery first. Water that reaches connectors and control modules can cause short circuits. The faults that follow can be slow and expensive to trace, a pattern Edmunds calls "electrical gremlins."

The third is the title. A branded title records serious damage, and a flood salvage brand tells the next buyer what happened to the car. State registration laws differ considerably, and that gap creates an opening. A car branded in one state can be moved to another with different rules and sold with a clean-looking title. Edmunds calls this practice title washing and says it happens not infrequently and can be hard to spot. Its example is a car flooded in Florida that later turns up for sale somewhere like Arizona, where buyers may know less about what to look for.

Avoiding a water-damaged car comes down to groundwork. The vehicle identification number is the starting point. A history service such as Carfax can show whether a seller's account holds up. The National Insurance Crime Bureau runs a free VINCheck tool that can serve as a second check. The National Motor Vehicle Title Information System is another resource for shoppers worried about a vehicle's past.

Not every flood car is beyond saving. A car that is merely damp and smells musty but works normally may recover with a full interior removal and a thorough dry-out. Multiple intermittent electrical faults point to something far more serious.

The 10 slides that follow cover a selection of checks and warning signs for spotting a flood-damaged car before money changes hands. Each one stands on its own, from how mold takes hold in a soaked cabin to which electrical repairs are realistic and which are not.

Illustration: Quartz

Carpets and seats in a flooded car soak up water that is difficult to remove completely. A car that is not dried out properly can grow mold. Edmunds describes black mold as extremely dangerous.

Mold is a fungus, a tiny organism that thrives in wet conditions. It can grow indoors on surfaces that stay moist. Mold spores grow when they settle in spots with too much moisture. Places where flooding has happened are among them.

Wet carpet and upholstery are not the only concern. Edmunds notes that floodwater also collects in small crevices throughout the cabin. If those pockets stay wet, the humidity inside the car rises. That extra humidity then encourages more mold to grow.

The same conditions raise the risk in buildings. Homes are more prone to mold after floods, leaking pipes, high humidity or poor airflow.

Mold does not always show on the surface. It can hide under or behind carpet, cushions and walls. Carpet and seat cushions are both standard in a car interior. In buildings, contamination inside wall cavities and ceilings is common after a flood.

Smell can signal hidden growth. Molds release volatile organic compounds, most commonly ethanol. Those compounds produce the musty odor associated with fungal growth.

Appearance offers another clue. Mold usually looks thick and fuzzy, with a green or black color. Mildew tends to look powdery and lies flat against a surface.

The health effects vary from person to person. People allergic to mold spores may develop irritated eyes, a lasting cough, headaches, nasal and sinus congestion, a skin rash or a sore throat. People with asthma or mold allergies can have severe reactions. Those who are immune-compromised or have chronic lung disease may develop lung infections.

Invasive mold infections are rare. In people with weakened immune systems, they can reach blood vessels, deep tissues or organs. These infections can be serious and life-threatening. Flood-affected areas carry a higher risk of them.

Illustration: Quartz

Floodwater damages a car's electronics by reaching its electrical connections and modules, where it causes short circuits. Edmunds notes that the owner of a flooded car most likely had no chance to disconnect the battery before the water arrived.

A modern car depends on wiring, connectors and control modules to run systems ranging from the engine to the power windows. Water that gets into those parts can carry electricity along paths it was never meant to take.

Edmunds warns that the result can be a long run of electrical faults. It calls them "electrical gremlins." Those problems can take a lot of time and money to trace to their source.

Damage of this kind does not always show itself right away. The National Highway Traffic Safety Administration warns that flood damage can affect a vehicle's mechanisms for years. It adds that the damage may not cause a visible problem at first. A car that runs normally on a test drive can still carry water damage.

Repair guidance from commercial truck makers describes the same process. A Hino service bulletin explains that water can seep into the wire harnesses, connectors and modules of a flooded truck that looks undamaged. The bulletin warns that the corrosion that follows can lead to electrical shorts and fires. It also states that connectors and modules are not built to withstand water. Any connector that has been under water, for any amount of time, should be opened and checked for moisture and corrosion, according to the bulletin. A connector that cannot be cleaned has to be replaced.

A Freightliner flood damage repair bulletin lays out similar steps. It advises disconnecting electrical connectors, drying them with compressed air and cleaning them with electrical cleaner. Corroded connectors, pins or harnesses get replaced as needed.

The kind of water matters too. The Hino bulletin tells technicians to find out whether a vehicle sat in fresh or salt water. Salt water corrodes more aggressively and breaks down wire harnesses faster, according to the bulletin.

Illustration: Quartz

A branded title is a vehicle title that carries a notation of serious damage. A flood salvage brand records on the car's official paperwork that the damage came from water.

That record matters because flood damage does not always show. A car can be cleaned inside and out and look ordinary on a dealer lot. The trouble can also arrive late. Flood damage can affect a vehicle's mechanisms for years and may not cause a visible problem right away. The brand is a written account of a history that a tidy cabin might hide.

The brand also tells a shopper where to look first. Edmunds identifies the upholstery and the electrical system as the places floodwater does its harm. A car with a flood salvage title calls for a close look at both before a deal is signed.

The brand shapes the conversation with the seller, too. A buyer looking at a flood-branded car can ask how it was dried, what was replaced and what still works. Those answers can then be checked against the car itself.

What counts as a branded title is not the same everywhere in the U.S. Edmunds notes that vehicle registration laws differ considerably from state to state. Those differences extend to the rules on what qualifies as branded. The notation a car carries depends on the state that issued its title.

For that reason, a clean title is not, by itself, proof that a car stayed dry. A title reflects only what one state recorded under its own rules. A title brand works best as one piece of evidence. A vehicle history check and a close inspection of the car fill in the rest.

Illustration: Quartz

Title washing strips a flood record from a car's paperwork. A seller takes a vehicle with a flood salvage title in one state and sells it in another state that has different rules about what counts as a branded title.

A branded title notes that a vehicle has suffered serious damage. A flood salvage brand tells the next buyer that the car has been underwater. Title washing targets that notation. It does not repair the car. It moves the car to a state where the paperwork reads differently.

The tactic depends on the patchwork of state rules. Edmunds explains that title washing is possible because state laws on vehicle registration differ considerably. Each state decides for itself which vehicles get a brand. A car can therefore leave one state with a flood salvage title and be offered for sale in another state without the same label.

Edmunds illustrates the scheme with a car that flooded in Florida and is later sold somewhere such as Arizona. Buyers in a state like Arizona may know less about what to look for in a flood car, according to Edmunds. The move puts a damaged car in front of shoppers less prepared to spot the problem.

Title washing is not a rare edge case. Edmunds reports that it happens not infrequently. The publication also notes that the practice can be hard to detect.

For a buyer, the consequence is direct. A title that shows no flood brand is not proof that a car never flooded. The car may have carried that brand in another state before it arrived on the lot.

Illustration: Quartz

Before looking at the upholstery or the wiring, get the car's vehicle identification number and run it through a vehicle history service such as Carfax. Edmunds names this as the first step for a shopper trying to avoid a flood-damaged car.

The check tests the seller's account against an outside record. A seller may describe a car as accident-free. A seller may also say it has never been near a storm. A history report lets the buyer see whether the paper trail supports either claim.

The vehicle identification number, or VIN, ties one specific car to that record. Without it, a buyer has only the seller's word to go on. With it, the buyer can look into the car's past before spending time on a closer inspection.

Order matters here. A clean, freshly detailed cabin says little about where a car has been. The paperwork comes first, and the physical inspection follows.

Edmunds presents the history service as a way to verify what the seller says. It does not describe the report as the final word on a car's condition.

Illustration: Quartz

The National Insurance Crime Bureau offers a free VINCheck service that can back up a Carfax report, according to Edmunds. It gives a used-car shopper a second look at a vehicle's record at no cost.

Edmunds presents VINCheck as a supplement to a Carfax report, not a replacement for it. A shopper who has already run a car's vehicle identification number through Carfax can enter the same number into VINCheck.

The value lies in corroboration. A single history report offers one view of a car's past. When a second record lines up with the first, the seller's account rests on more than one source.

When the two records disagree, the gap becomes a question for the seller. That conversation belongs before any money changes hands, not after.

The service costs nothing to use. A shopper comparing several used cars can run each one's VIN early in the search. That happens before any time goes into a closer inspection of the cabin or the wiring.

The check depends on the number entered. Copy the VIN from the car itself rather than from an online listing or a seller's message. That ties the result to the vehicle actually on offer.

Illustration: Quartz

If you worry that a used car has a checkered past, search the National Motor Vehicle Title Information System. Edmunds describes it as an excellent resource for shoppers with exactly that concern.

The system, often shortened to NMVTIS, centers on title information, as its name indicates. That focus matters for flood cars. Serious damage is supposed to appear on a car's title as a brand. A flood salvage title marks a vehicle that has been through high water.

Title records do not always follow a car cleanly. Edmunds points out that state registration laws differ considerably. A car branded as flood salvage in one state can be resold in a state with different branding rules. That practice is known as title washing. A title that looks clean in one state does not settle what happened to the car in another.

Edmunds presents NMVTIS as one of several record checks, not a substitute for the others. The starting point is the vehicle identification number, or VIN. A vehicle history service such as Carfax and the National Insurance Crime Bureau's free VINCheck tool are other places to run it. A title system search gives a shopper one more record to hold up against the seller's account of the car.

Illustration: Quartz

Edmunds lists three electrical symptoms that point to serious flood damage. They are several faults that come and go, features that do not work at all, and fuses that keep blowing during routine driving. Each is a reason to look more closely before a sale goes through.

An intermittent fault is one that shows up, disappears and then returns. Edmunds singles out multiple faults of this kind as the warning sign, not one isolated glitch. A dashboard warning light that comes on one day and stays dark the next fits the pattern. So does a power window or door lock that responds on some tries and not on others.

A feature that does not work at all is easier to catch, provided the shopper looks for it. That means operating every switch, light, lock, seat control, speaker and screen function during an inspection instead of assuming the basics work. A dead circuit on a car that otherwise looks clean is a mismatch worth asking the seller about.

Repeatedly blown fuses are the third sign. A fuse is built to burn out when too much current flows through a circuit. That protects the wiring from overheating. One blown fuse can have an ordinary explanation. A replacement fuse that fails again under normal use points to a fault in the circuit itself, such as a short.

These symptoms may not appear on a single test drive. The National Highway Traffic Safety Administration reports that flood damage can affect a vehicle's mechanisms for years and may not cause a visible problem right away.

Hidden corrosion is one way that damage stays out of sight. A Hino service bulletin on flooded trucks describes water seeping into wire harnesses, connectors and modules on vehicles that look undamaged. The corrosion that follows can lead to electrical shorts and fires, according to the bulletin.

For a buyer, the useful habit is to test each electrical feature more than once. A run of repeated failures, rather than a single quirk, is the pattern Edmunds connects to serious flood damage.

Illustration: Quartz

A flood-exposed car that is only damp and smelly, with every system still working, may need nothing more than a thorough cleaning. Edmunds places that case at the mild end of its answer to whether a flooded car can be fixed.

The cleaning Edmunds describes is not a quick detail job. It means removing the entire interior and drying it completely. The seats, the carpets and the rest of the interior come out of the cabin. Each piece can then dry on its own, and so can the bare floor beneath.

Stripping the cabin matters because mold can hide out of sight. The CDC reports that in buildings, mold can sit under or behind carpet and cushions. A car cabin is built from the same kinds of soft materials. A seat or floor covering that looks dry on top can still conceal growth underneath.

Edmunds' standard calls for complete drying, not partial drying. The National Institute of Environmental Health Sciences describes mold as a fungus that does well in wet conditions. Its spores grow when they land somewhere with too much moisture, including places that have flooded, according to the CDC.

The smell that marks a car as a candidate for this fix has a known cause. Molds release volatile organic compounds, and ethanol is the most common of them. Those compounds create the musty odor associated with fungal growth.

With the interior out, visible growth is easier to identify. Mold usually looks fuzzy and thick, with a green or black color. Mildew tends to look powdery and lies flat against a surface, according to the institute.

The second half of Edmunds' test is that everything still works. A damp car that also shows electrical faults needs more than this kind of fix. A shopper looking at a car a seller says was cleaned after a flood can ask a direct question. Was the entire interior removed and dried completely, as Edmunds describes?