Everyone knows instinctively that it’s a bad idea to drive internal combustion engine cars through deep puddles (unless, of course, the manufacturer’s specifications say you can). But what, exactly, is so bad about this practice? Why do regular cars conk out when you plow through a deep river or flood water?
Cars can (and will) suffer water damage
The main problem of driving through deep water is water damage. While manufacturers make vehicles to be water-resistant, most can’t survive being totally submerged for more than a few seconds.
Most rain falls onto the chassis and then runs in channels onto the ground. The interior of the vehicle remains perfectly dry and damage-free.
But when you plow through a deep river, water gets into places it shouldn’t, causing damage to electric components, your drivetrain, and the engine itself.
A hydrolocked motor is one of the most severe issues. Water essentially gets into the engine compartment, preventing fuel and combustion from doing its job. At this point, the vehicle ceases to function and no amount of spark plug activity is able to get it going again.
Electrical problems
Related to this, your vehicle may also suffer significant electrical problems. Sensors, onboard computers, and ignition systems can all experience extensive damage when exposed to water.
Again, manufacturers do a pretty decent job of shielding these from rain and moisture in the atmosphere. However, full submersion is a different story. Many cars fail to start after driving through deep water because it damages the start-up system and causes sensors to malfunction in a way that puts the car into rescue mode.
Brake problems
You may not be aware of this issue, but driving your car through deep puddles and rivers can also lead to brake problems. Wet brakes don’t perform as well as dry and can’t grip the rotor as well. This effect results in reduced braking performance, potentially putting you at risk.
Losing traction
Driving through puddles can also result in a loss of traction. While dry sections of road or track are usually clean, flooded areas or rivers can be full of sediment, preventing the tires from properly gripping the road.
This loss of traction can then cause the vehicle to spin out of control, especially if you try to turn. Deep water can hide grip issues and other objects that make driving through them hazardous.
Action items if one of your cars encounters deep water while driving
Most of the time, driving through deep water is avoidable. You can simply postpone your trip or find another route to your destination.
However, if you need to drive through the water, ensure you adopt some best practices.
For example, slow down before entering the water. Minimize the amount of splash and the force of the impact. Ripples in the water can make the level higher in places, increasing the likelihood of it getting into your engine.
After exiting a section of deep water, tap the brakes to check they still work well. Make sure you have plenty of stopping power so you don’t get caught off guard at traffic lights or intersections.
