Experience in handling flooded cars

A good rule of thumb for drivers is to never force the engine to restart when the car stalls to avoid bending, breaking, or puncturing the cylinder wall.

Water not only affects the electrical system, dirtying the interior, but more seriously, it also damages the engine when it enters the combustion chamber. This causes water compression, also known as hydro-hammering.

Engines, electrical systems, and engine oil are easily damaged when cars travel through flooded areas.

Below are the parts most easily affected when a car is flooded and basic ways to handle them:

Engine

The driver must absolutely not attempt to restart the vehicle, turn off the electrical system and, if possible, push the vehicle to a high, inclined area. This will both prevent water from entering the combustion chamber through the air intake and allow water to escape through the exhaust pipe.

GCall for help to check the extent of water ingress into the engine. If the damage is minor, the car can be slowly driven back to the garage for further inspection when the water level on the road allows. In more serious cases, the car may need to be transported or towed back to the garage by a specialized vehicle.

The owner of a Mercedes E-Class forced the car to start after it stalled due to water bending the connecting rod in the engine.

Trying to restart the engine will only cause further damage. The incompressible nature of water causes the connecting rods in the combustion chamber to warp due to the reciprocating action of the piston.

More dangerously, forcing the car to start repeatedly can cause the connecting rod to bend, break, or puncture the cylinder wall (break the engine block). The engine must therefore be repaired or replaced at a high cost depending on the type of car.

The connecting rod broke, piercing the cylinder wall in the car engine.

According to auto technicians, even when the car is in the garage, starting the engine must be done carefully. First, turn the engine by hand to check if the engine is jammed by foreign objects. Then continue to measure the engine compression pressure with a specialized tool.

If the compression pressure is still sufficient, it means that water has not entered the combustion chamber and the engine is still good. At this point, you can start the car again, but do not forget to check other parts for repair if there are signs of damage.

If the engine compression pressure is not enough, it means the engine is damaged. Disassemble the engine to check the internal parts such as cylinders, pistons, connecting rods, crankshaft. Depending on the severity, repair or replace.

Electrical system

Similar to the engine, the electrical system is also sensitive to water. Short circuits and damage to the vehicle's control system occur when water penetrates from the undercarriage to the floor. This leads to errors in parts or many functions of the car may malfunction. The deeper and longer the vehicle is submerged in water, the more likely the electrical system is to be damaged.

Typically, the electrical systems of flooded cars require detailed computer-aided inspection for repairs. The connectors are dried and sprayed with specialized chemicals to prevent oxidation.

Lubricant

When driving through flooded areas or deep water, the first thing to do after turning off the engine is to check the engine oil. When the oil turns milky white due to mixing with water, drain all the old oil and replace it with new oil. Engine oil and gearbox oil are separate.

Unlike motorbikes, cars with automatic and manual transmissions use oils of different viscosity. Depending on the type of vehicle or manufacturer with its own technical standards, using oil for cars needs to be considered and performed by reputable garages.

According to VNE