What can you do to "save" a flooded car?

When driving through flooded areas, turn off the air conditioner (AC button), shift to first gear, maintain a steady and moderate speed, keep the engine running smoothly, and drive calmly...

Cars submerged in water are very harmful to the bearings under the vehicle, affecting the starter motor, alternator, fans, electrical components, sensors, and control unit, making them very susceptible to damage. Water ingress reduces the effectiveness of the clutch, brakes, etc.

The causes are mostly due to water entering the engine's air intake pipe, some due to electrical short circuits, some due to parking in low-lying areas where water gets into the vehicle, and in some exceptional cases, the vehicle is damaged because the fuel tank is full of water.

If the water level is high, it will be sucked into the engine's air intake and cause damage; at best, it will bend the connecting rods, at worst, it will damage the crankshaft and crack the engine block. This is the phenomenon of "hydro-locking." When the engine is running normally, the pistons are moving up to compress the air-fuel mixture at a speed of about 1000 rpm. Because the air-fuel mixture has been displaced by water, and because water is incompressible, this compressive force creates a reaction force that deforms the connecting rods and pistons. If the connecting rod bends too much, it will break, and this broken piece will puncture the engine block, destroying your vehicle.

Driving principles when driving through flooded areas.

When forced to drive through flooded areas, it's advisable to remove the engine air filter to draw air directly from the engine compartment, as this is the highest point, avoiding the vehicle's intake system which is lower. Once you've passed the flooded area, you can reinstall the engine air filter.

Turning off the air conditioner (AC button) is the first thing to do when your car has to drive through a flooded area.

The safe water level warning is below 25 cm, not exceeding the center of the wheel; above that level, you should not drive through. In addition, pay special attention to vehicles traveling in the same and opposite directions, as this can create waves, causing the water level to rise and increasing the risk of water entering the air intake and engine air filter.

When driving through flooded areas, turn off the air conditioner (AC button), use first gear, maintain a steady, moderate speed, keep the engine running smoothly, and drive calmly. For automatic transmissions, switch to semi-automatic mode and stay in first gear. If left in automatic mode, the car will automatically shift to second gear, causing a loss of power and allowing water to enter the engine through the exhaust pipe. Note that you should not depress the clutch in manual transmissions when driving through flooded areas to avoid stalling.

Avoid accelerating aggressively because strong acceleration can cause water to overflow the radiator grille and enter the intake manifold. Additionally, sudden acceleration increases engine RPM, and if water enters, it can worsen the hydraulic lock phenomenon, potentially causing the connecting rods to bend.

After passing through the flooded area, you need to continue driving for a short distance, gently applying the brakes to remove excess water from the brake discs. Then, get out and check the engine and undercarriage.

If your car suddenly stalls in a flooded area, absolutely do not try to restart it. Instead, remove the ignition key, push the car to higher ground, and immediately call for roadside assistance. The way to handle a flooded car varies, so do not attempt to fix it yourself if you lack technical expertise.

When calling for roadside assistance, drivers should also note that if the vehicle is equipped with an automatic transmission, anti-slip system, automatic differential lock, anti-rollover stability control, or full-time four-wheel drive, it should only be towed using a flatbed tow truck (with all four wheels stationary).

Furthermore, do not open the doors immediately when the engine stalls; pay attention to the water level. If the water level is higher than the lowest part of the door, absolutely do not open the doors, as this will cause water from outside to flood in and damage the electronic systems. In this case, you should open the windows to get in and out of the car.

Interior cleaning and maintenance

According to advice from technicians and mechanics, if you discover that your car's interior has been soaked with water, it's best to quickly find a familiar auto repair shop to clean it before it starts to smell, especially for cars with fabric or leather upholstery. Depending on whether the car has a fabric or leather interior, the cleaning process will be slightly different.

The fabric itself is very "sensitive" to dirt, and the car's interior is quite limited in space, so the entire interior must be thoroughly cleaned. The plastic trim pieces will be scrubbed carefully with a brush, alcohol, and specialized cleaning solution. The seats, floor mats, and soundproofing underlays are all removed and washed.

The car seats, in particular, must be machine-cleaned to ensure they are as clean as new. The repair technicians will use a water pump and chemicals to clean the fabric and foam, then use a vacuum to remove the dirty water. This process is repeated several times. Once clean, the seats, cushions, and floor mats will be dried by air drying or machine steaming. Next, the technicians will remove the drain holes in the car floor, rinse with water, and blow dry the floor. After reassembling the interior, the final step is to apply a scented cleaning solution to the interior surfaces.

The bottom support of the vehicle floor is made of metal and treated with soundproofing materials, making it very airtight. When water enters through the doors and seeps down, it forms large water pockets that cannot drain away naturally. The air conditioning ducts become dirty, and may even become clogged, when dirty water enters.

After draining all the water, use a hairdryer to dry everything. Bolts and screws that get soaked in rainwater can rust quickly, so it's important to apply rust-preventive oil and grease when cleaning the vehicle floor.

The wiring and connectors running around the vehicle, particularly in the center console area, are highly susceptible to short circuits and fires if water remains inside. The connectors need to be checked and dried to ensure proper contact. Deeply submerged car doors will accumulate a lot of water inside, affecting the operation of speakers and wiring; therefore, this area cannot be overlooked during the interior cleaning and restoration process.

Scan for control system errors.

On many car models, especially Japanese cars, the airbag control system is located directly under the floor in the center console area. Water ingress can disable this system. Cleaning and inspection must be carried out with extreme care, otherwise it will affect the entire airbag system.

In high-end vehicles, the center console houses numerous complex control systems such as the transmission, intelligent multi-function control system, and communication system. The cleaning process must be handled by experienced professionals. The control components most susceptible to water damage are the seat control switches and the numerous motors/engines inside the seats. Water can burn out the motors and disable the seat controls.

Maintaining electrical and lighting system components involves more than just draining water and drying them; it also requires assessing their operational condition, identifying potential risks such as short circuits, exposed wires, or corrosion at the contacts. A crucial step, especially in high-end vehicles, is resetting the system using a diagnostic scanner.

According to Vov.vn