You often see people driving through deep water after a storm or a hurricane. Even all the ‘turn around, don’t drown’ warnings, they still drive through deep water. However, there’s a lot that can go wrong when you drive through water, according to Scotty Kilmer.
Why should you avoid deep water?
In addition to putting your life at risk because you can’t see how deep the water is, you also risk your vehicle’s engine.
A deep hole or washed-out bridge could be under the deep water.
You could get caught in a flash flood in areas that have water running over the road, especially if a river or stream is running under a bridge with deep water over the bridge.
You could very easily damage your vehicle.
To minimize injury to you and extensive damage to your vehicle’s engine and interior, always avoid deep water. Water that is merely six to eight inches deep could damage your vehicle’s engine.
When You Might Drive Through Deep Water
It’s never a good idea to drive through deep water. However, if you have to take the chance with endangering your life – maybe because another person’s life is at stake – you should know the location of your vehicle’s air intake.
This is not the air filter in the housing, which is often on top of the engine. Many vehicles have an air dam that picks up air near the bottom of the vehicle, usually by the bottom of the fender. Water six inches deep could get sucked up into the engine.
When you drive through water, your vehicle makes waves, no matter how slow you drive. That one- or two-inch wave is enough for your vehicle to suck up a lot of water. If you know the air intake is higher than your vehicle’s tires, then you might chance driving through water.
If you have to drive through the water, you should get out of the vehicle to make sure there is solid ground under the vehicle. But again, only in a dire emergency.
If a mudslide or flash flood happens while you are in or out of your vehicle, you’ll get swept away and could possibly drown.
How Water Damages Your Vehicle
Water that gets inside your vehicle and your engine can – and usually does – cause extensive damage.
Damage to the Interior of Your Vehicle
If water gets inside the vehicle, the seats, carpet, and many electronics get soaked. If you don’t clean the water out of any of the soft-touch materials in your vehicle, it will cause those materials to mold, including the underside of the carpet.
You might also have electrical problems. If the water gets deep enough to get behind the door panel, you could damage electric windows, locks and mirrors. Many vehicles have computers located under the seat. The water doesn’t have to get very high to damage any of the computers stored on the floor.
Damage to Your Vehicle’s Engine
The most extensive damage is when water gets into your engine. When the air intake sucks water into the engine, it goes through the same path the air goes through – right into the internal workings.
Under normal circumstances, your car sucks in air and it mixes with fuel in the intake manifold. The intake directs the fuel and air mixture to each of the cylinders. After the air and fuel – or water, if you the engine sucks water in – is directed to the cylinders:
- The first stroke of a four-stroke engine is when the crank draws the piston down. This is the intake stroke. This brings whatever is in the intake, including water that’s not supposed to be there, into the cylinder.
- The next stroke is when the crank pushes the piston up. This is the compression stroke. And it is here that you run into major issues. Water cannot be compressed. If you have just air and fuel in the cylinder, the compression stroke compresses the mixture, making it explode.
- The explosion then pushes the piston down. This is the combustion stroke.
- The last stroke is when the piston rides back up and is called the exhaust stroke.
Since water cannot be compressed, things start to happen. The weakest point in the system fails.
Usually, that is the rod. The rod connects the piston to the crankshaft.
Since the water stops the piston from traveling all the way through the cylinder, either the rod has to give, the sides of the cylinder have to explode, or the valves are forced open and the water gets back into the intake.
In most cases, the rod bends. As the engine continues rotating, the bent rod could hit the side of the cylinder and it also moves the piston at such an angle that the piston either crumbles or does extensive damage to the cylinder walls.
Keep in mind that, with a car engine, for every action, there’s a reaction. The pistons are attached to the crankshaft, which is attached to the camshaft via a chain, gears, or belt.
The out-of-balance bottom end could then affect the top end, and cause valves to hit pistons and could even damage the camshaft, depending on how much compression your engine has.
Usually, by the time you damage the bottom end, the engine quits, but there’s always a chance of doing more damage to the top end.
Instead of taking the chance of losing your life, suffering injuries from a mudslide or flash flood, damaging the engine or totaling your vehicle, avoid driving through deep water.
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