Skip navigation

Flooding poses risk for used-car buyers

Recent unprecedented wet weather could see water-damaged cars flooding on to the market, experts warn. We explain how to avoid being duped.

This winter’s terrible weather could have implications if you’re about to buy a used car.

Over recent months thousands of vehicles are estimated to have been damaged by flood water.

Passing on problems

Now trading service AA Cars is concerned that many owners could attempt to sell these motors without warning potential buyers of the problems.

AA patrols say they have rescued more than 3,000 cars from flood water since 20 December last year.

But David Bruce, director of AA Cars, warns: "Many owners may not tell their insurer their car has been affected by flood water and attempt to dispose of it through the used-car market.

"This could pass on potentially disastrous problems to an unwitting buyer."

Prime time for sales

Along with September, March is typically the busiest month for car sales, both new and used, as this is when new registrations are issued.

Buyers of second-hand vehicles should be particularly careful when looking at 4x4s.

This is because the AA found a disproportionate number of the cars that their staff were called out to rescue were off-road or all-terrain vehicles.

The AA’s Simon Douglas says that this was because many 4x4 owners mistakenly believed that their cars could "cope with anything".

How flooding can damage cars

It is estimated that insurers write off around 70% of cars which have been immersed in flood water.

Bruce says this is because the water either damages the engine or affects electrical systems, which could compromise the car’s safety.

"If a car engine – regardless of whether it’s a small family hatchback or a 4x4 – draws even an eggcup-full of water through the air intake, the engine will almost certainly be wrecked," he explains. 

"And in most cases the car will be written off."

But Bruce is worried about cases where a vehicle has been in water but there is no immediate or obvious impact on the car.

‘Problems could emerge later’

"While a car can be dried out with no obvious visual damage, immersion in floods can store up a range of potentially costly or dangerous problems that could emerge at a later date," he says.

"For instance, catalytic-converter and exhaust-system life can be seriously compromised.

"And there can be host of potentially serious electrical problems – including airbags spontaneously going off with a risk of injury."

Most buyers won’t be able to carry out a detailed mechanical check before the purchase.

Water damage warning signs

But AA Cars has come up with a number of warning signs which could indicate a car has recently been damaged by flood water:

  • Windows are left open to help ventilation, and the seller is using air fresheners to mask damp smells. Buyers should check carpets and upholstery for signs of damp.
  • If the car steams up when the screen heater is switched on, it could signify moisture in the car.
  • A white emulsion on the underside of the oil filler cap may mean there is water in the engine oil. Equally this problem could be caused by a leaking head gasket, which would also need to be addressed.

Bruce says that buyers should just walk away if they do not feel confident about their purchase: "If in doubt, don’t buy it. There will always be another one."

Compare car insurance - you could find a great deal in minutes Get a car insurance quote


Chris Torney

Chris Torney

Chris is the former personal finance editor at the Daily Express. He's been a journalist for more than 10 years and contributes to a wide range of finance and business titles.Read more from Chris