Typically, if you're buying a used car, you know to check the tires, the engine and make the car is drivable. But, how can you be sure this new to you car was not once underwater due to a flood?

Now that the historic flood waters from Hurricanes Harvey and Irma have receded, the next flood could be a wave of water-logged cares headed to a lot near you. And they could have a boat-load of problems.

Flood-damaged vehicles sold without disclosing the damage is illegal in most states, but that doesn't mean it won't happen.

Jon Linkov, Consumer Reports Auto Editor said, "Too often, when an insurance company declares a flood-damaged car a total loss, that information isn't communicated to potential buyers."

Consumer Reports found that some flood-damaged vehicles are sold with clean titles; meaning a flood-damaged car could easily find its way back into the used-car market. If a car doesn't carry maximum insurance, flood-damage may not be disclosed in the car's title.

Consumer Reports said a mechanic should conduct a thorough inspection, but there are things you can do too.

"The first thing you want to do is come over to the front of the car. Inhale and see if there's any kind of moldy or musty smell. If you have that you definitely want to walk away from the car," said Linkov.

Next, pop up the trim panel on the side of the door to see if the carpet is dirty or if there's any kind of sediment in or rust.

Also, look in the door pockets for sediment or dirt or stones; that's what happens when the water came up and into the car, and as it drained away it settled.

Pop off some of the caps and covers for the seat bolts. If these are scratched up or even look rusted, that means the seat was taken out so it could air dry.

Look where a spare tire would be kept to check for musty or moldy smelling. Make sure to see if there's any rust on exposed screws, on the panels, or even on the tools like the jack or the jack stand.

And although helpful, Consumer Reports said vehicle history reports are no guarantee that a car is problem-free.