5 signs you're looking at a flood-damaged car — how not to buy a car after a flood

1. Musty smell and mould in the interior

The most obvious sign is an unpleasant musty smell inside. If you open the doors and a damp, “swampy” odour hits you, that’s a red flag. Interior fabrics soak up moisture and even a deep cleaning doesn’t always remove the smell completely. Pay attention to strong air fresheners: an overpowering “tree” fragrance can be there to hide mould.

Look carefully for visible mould or fungus: a greenish coating in corners, under floor mats, behind trim panels. Mould can appear on seat upholstery, under the headliner, and in the boot (trunk) wells. Pay special attention under the carpets: lift the floor mats and sound insulation — you may find water marks, dampness or typical stains left by dried water. Even slightly damp floors or rusty seat mounting brackets are a reason to be suspicious.

• Check air fresheners. Very strong fragrances can be used to mask a mouldy odour.
• Look for fungal growth. Greenish or grey mould in corners, under mats, behind trim, in the boot.
• Lift carpets and insulation. Water marks, dried “tide lines”, dampness or rusty seat brackets are all warning signs.

A healthy, dry car interior does not smell of damp and certainly doesn’t grow mould. If someone had to “kill” the smell with litres of perfume, the car’s history is probably very wet.

2. Rust and corrosion in hidden areas

Rust is a faithful companion of flood cars. Inspect the bodywork from below and from inside as far as you can without a lift. The paintwork may shine on the outside, but rust will give itself away in hard-to-reach places.

Check body seams and joints: under the sills, inside the wheel arches, under the spare wheel in the boot, behind boot trim panels. If you can use a pit or ramp, a quick look at the underbody is also helpful. But even without that you can see a lot: peek under the bumpers, into the sill gaps, use a torch or your phone camera.

Look for rusty streaks, flaking paint, bubbling and rough metal – traces of water that has stood inside cavities. Weld seams and boxed sections are especially vulnerable: boot floor, under seats, inside doors. Even the bolts can betray a flood: seat mounting bolts, hinge bolts for bonnet and doors, dashboard fasteners – if they are covered with fresh rust or bloom, that’s bad news. In a normal car these parts are dry and just dusty, whereas here the metal can clearly be “flowering”.

Also check the back side of the seat belts: in a flood-damaged car, metal belt parts can be rusty. Another indicator is salt deposits: whitish salt crystals on carpet, seats or bare metal. They are left behind by dried sea or dirty water and are hard to remove. If you see dried streaks and mineral lines under any trim or carpet, the car may well have been under water.

• 📜 Body seams and joints. Sills, arches, spare-wheel well, boot floor, internal cavities under trim.
• 📜 Welds and boxed sections. Rust streaks, peeling paint, bubbling – all signs of prolonged water contact.
• 📜 Fasteners and bolts. Seat bolts, hinges, dashboard mounts should be dusty, not freshly rusty.
• 📜 Seat belts. Pull them out to the end and inspect the metal parts and fabric along the full length.
• 📜 Salt stains. Whitish crystals on carpet, seats or metal are typical traces of dried dirty or salty water.

If you find dried streaks and “tide lines” under the carpet or trim, the chances are high that the car has been swimming.

3. Issues with wiring and electronics

Electrical systems are extremely vulnerable to flooding. Even if wiring and control units were dried, the consequences don’t always show up immediately.

With the bonnet open, look for corrosion: greenish deposits on wire contacts, plugs and terminals are a clear sign that water has been there. Check the fuse box and connectors in the engine bay: if copper contacts are dark or covered with a blue-green layer, they have corroded after getting wet. In a healthy car, the wiring is dry and clean; here you may see patina or rust.

Inspect the condition of the wiring itself: the insulation should not be stiff or cracked. Water speeds up ageing of insulation and the conductor can corrode inside. Try switching on all electrical systems: faults in electronics (climate misbehaving, rear demister not working, random warning lights) can point to past short circuits caused by water.

Pay particular attention to hidden electronics: airbag modules, ABS sensors, connectors under the carpet. Even if everything seems to work now, a flood car has a high risk of “ghost” errors: mysterious electronic glitches that appear months later. Burnt or corroded connectors are a strong reason to walk away from the deal.

• ❗ Corroded contacts. Green or blue-green deposits on plugs, terminals and fuse boxes are a water footprint.
• ❗ Insulation condition. Stiff, cracked insulation and darkened wires show accelerated ageing after moisture.
• ❗ Electronic glitches. Flickering warning lights, non-working demister, weird climate behaviour, intermittent errors.
• ❗ Hidden modules. Airbag, ABS and connectors under the carpet are places where water often sits the longest.

Even if everything seems fine at the moment, a flood car is highly likely to develop “mystery” electrical issues later. Corroded contacts are a strong argument to refuse the purchase or negotiate a very serious discount.

4. Moisture in headlights and components

Lighting units also suffer badly from flooding. Check the front headlights and rear lights for condensation or droplets. If you see foggy areas or streaks inside the headlight lens, moisture has been inside. It’s especially suspicious if the lights constantly fog up – even after bulb changes and drying.

Normally, healthy headlight units are sealed and do not mist up. In flood cars, microcracks or damaged seals often remain, letting moisture stay inside the lights. Another common trick from sellers is brand-new lights: if they look too new (perfectly clear, no micro scratches) compared to the rest of the car, the old ones may have been changed due to corrosion or electrical damage.

Check the markings and production year on the headlight housing: very “fresh” lights on an older car are a reason to ask questions.

Also look at other assemblies for signs of moisture: for example, inspect the air filter – a badly deformed, very dirty element with traces of silt may indicate that dirty water has been there. Engine oil is another marker: a milky emulsion on the dipstick or filler cap shows contact with water. Of course, before selling, most sellers change all fluids and filters, so it’s not easy to catch direct traces. But if you do see fresh emulsion, walk away immediately.

One more tip: pay attention to the air-conditioning and ventilation system. Excess moisture can remain in the ducts. Sometimes, when you start the climate system in a flooded car, you get a mouldy smell or even small debris from the vents. Water may also have carried sand and silt into body cavities: sills, chassis rails, inside bumpers. If possible, look under boot trim panels or remove plastic sill covers – flood “heritage” is often very visible there.

• 📌 Misty headlights and lights. Droplets, streaks and persistent condensation inside point to lost sealing after water damage.
• 📌 Suspiciously new lights. Headlights that look much newer than the rest of the car – check the production year on the housing.
• 📌 Air filter. Strongly deformed, dirty or with silt residue – a possible sign of water ingress.
• 📌 Oil and emulsion. White “mayonnaise” on the dipstick or filler cap is oil mixed with water. Avoid such cars.
• 📌 Climate and ventilation. Musty smell or debris coming from the vents can indicate water and dirt in the ducts.

Water often carries sand and silt into cavities: sills, chassis rails, inside bumpers. If you can, look under boot trim or remove plastic sill covers – you’ll often see clear traces of the flood there.

5. Suspiciously new parts and signs of disassembly

Sellers often try to mask flood damage with cosmetic refreshes – new upholstery, carpets, headlights. It’s important to evaluate whether these parts match the overall age of the car.

• ❓ New carpets, retrimmed interior, “fresh” floor. All of this can hide a once flooded interior and removed original carpet.
• ❓ Traces of removed seats. Damaged bolt heads, chipped factory paint around mounts, rusty springs and dirt underneath.
• ❓ Seat belts. Belts that look too new for the car’s age, missing factory labels, or damp/musty smell along their length.
• ❓ Signs of body disassembly. Tool marks on hinge bolts, bonnet and boot bolts, disturbed paint around fixings.
• ❓ Suspiciously clean engine bay. On an old car, a perfectly steam-cleaned engine can sometimes mean an attempt to hide dirt and corrosion after water.

Each of these points alone is not yet a verdict, but a combination of 2–3 signs is a strong reason to dig deeper and continue the inspection more thoroughly.

How to spot a flood car without a lift

Most of the signs described above can be checked by yourself during a viewing. Take a torch, gloves and don’t be shy about looking into gaps and behind trim.

Check all accessible hidden areas: under the boot floor, under carpets, in wells, under seats, inside storage compartments. For an “underneath” look, you can simply lie down on the ground and inspect the lower sills, chassis rails and floor under the engine and boot – see if there is built-up dirt, grass, leaves or debris stuck there from the flood.

If you find at least 2–3 serious symptoms of flood damage, it’s usually better to walk away – in most cases you’ll be facing a long list of problems. A professional pre-purchase inspection (for example, in and around Berlin) will go much deeper than a visual check. Specialists know where to look and have the right tools, but even for them, the early signs you spot can help focus on the right areas.

• Check all accessible hidden areas: under the boot floor, under carpets, in wells and under the seats.
• Look under sills and bumpers; use your phone camera and torch to inspect tight spaces.
• To inspect the underside, lie on the ground and look at lower sills, rails and floor under the engine/boot.
• Search for accumulated dirt, grass, leaves and sand in unusual places – a classic flood footprint.
• Always order a VIN check and, if possible, an OBD scan to see error history and mileage.

Not confident in your skills? Bring in the experts

A truly independent pre-purchase inspection in Germany is a smart move whenever you have even slight doubts. This is especially true after major floods, when a wave of flood-damaged cars hits the market.

You can contact our Sicher-Check specialists: simply send a request via the contact form for an on-site inspection. We will carefully inspect the body and interior, measure paint thickness, perform VIN and OBD diagnostics, and assess the condition of electrics and hidden areas.

See our price list and options on the prices page. As a result, you’ll know that you’re not buying a car with a “dirty” (and literally wet) history.