MISSISSIPPI STATE -- Hurricane Katrina flooded thousands of vehicles in south Mississippi and Louisiana, and many of these soggy vehicles will soon start flooding used car markets across the rest of the country.

Some with just minor water damage can be dried out, cleaned up and small repairs made, but others that were fully or mostly submerged will be trouble. Experts say bacteria and mold can get established in wet cars, and airbags and anti-lock brakes usually fail in time if they get wet with salt water and rust or corrode.

Herb Willcutt, an agricultural engineer and safety specialist with the Mississippi State University Extension Service, said corrosion from salt water is a major concern with cars in the flooded zone.

“The body of a car soaked with salt water from the storm surge would rust out faster than normal,” Willcutt said. “Salt is very corrosive on any metal surface.”

Water, especially salt water, that reaches bright surfaces, or those that slide against each other such as shock absorbers, bearings or seals, can rust and corrode these, making them unusable.

The engine on a vehicle that has been submerged is likely full of water, including the fuel tank, engine compartments and cylinders.

“If you tried to turn it with a starter, you would probably almost immediately bend or break connecting rods, the crankshaft, valve train components and more,” Willcutt said. “I doubt that it would be worth the effort to salvage a car that has been submerged. Precautions to remove all the water before the engine is turned and to lubricate the parts could result in only minor damage. Even then, oil seals and exposed surfaces may rust or stick together or fail prematurely.”

Flooding ruins the interior of cars, including seats, carpeting, door panels, insulation and fixtures such as the stereo. Brakes rust when they are exposed to salt water, and if allowed to set long enough, can rust in place. Electrical connections go bad when allowed to get wet.

“The main problem is where connections are made in the wiring or in a bulb or socket,” Willcutt said. “These connections will corrode and not have good conductivity. Any switch or socket could corrode, becoming inoperative.”

To see if a car has been flooded, pull up carpeting in the trunk and look for rust, mud, dirt or sand. Feel under the floor mats for dampness, and check under the hood for an indication of a water line. Cars without these indications may still have been flooded, but these are worth checking.

Despite problems with the vehicles, some flooded cars are being bought at salvage and cleaned up just enough to resell. Grenell Rogers, Extension family resource management area agent in Oktibbeha County, urged used car buyers now more than ever to be vigilant when making a purchase.

“Make sure you research the car by getting the VIN number and checking it out with a service that provides history on the titles,” Rogers said. “Find out all you can from the person selling the car, and get a warranty in writing.”

A car sold “as is” carries no warranty, and any problem that arises is solely the responsibility of the new owner. A verbal warranty cannot be enforced, so get any promises in writing, even when buying from individuals.

“A person can say if something happens, they'll take care of it, but if it's not in writing, they may not do it,” Rogers said.

Many of the flooded cars are being sent out of state, but used car buyers everywhere should be careful.

“Be aware that flooded vehicles and salvaged vehicles are going to be on the market,” Rogers said. “By law, flooded vehicles should have ‘flooded' written on the title, but some people will still try to avoid this designation.”

One online resource for checking the history of a car is http://www.carfax.com. This sites allows users to enter a vehicle's VIN number and a history is provided. A fee is involved for some services. According to their Web site, a Carfax report may include flood damage or total loss history, odometer readings, service records and the number of owners, among other information.