Flooded Roads Can Damage Your Vehicle

You know that you should avoid driving into floods or high water. They can be very dangerous. That is especially true in Houston, where areas can flood rapidly and with little warning. Driving into floodwaters can put your life at risk. However, if you manage to get through flood waters safely, what can it do to your vehicle? You may be surprised to find out that even if your car seems fine, it could be damaged by driving into floodwaters. 

Before we look at what driving into floodwaters can do to your car, we will review why you avoid driving. 

You Do Not Know How Deep the Water Is

People consistently underestimate the depth of floodwater. It looks shallower from the surface. Even slight variations in the height of a road can translate to significant differences in water depth in the event of a flood. Almost every time it floods, we hear about people driving into water deep enough to sweep away the car. Sometimes, people even move into deep water to submerge their vehicles. 

A Little Flood Water Can Move a Lot of Car

A surprisingly small amount of floodwater can sweep away your vehicle. The exact amount depends on factors like the clearance of your car, the size of your tires, the weight of your vehicle. However, even a few inches of floodwater can potentially sweep away your vehicle. A foot of floodwaters can float most cars. 

You may think that a floating car is no big deal. Just stay in the vehicle and wait until it stops moving. However, that is simply not true. Running water tends to run to low points, which means you run the risk of being pushed into deeper or faster-moving water. If you stay in a vehicle being swept away, you may find yourself submerged. Other large pieces of floating debris could also hit you. 

A Passing Car Can Make Flood Waters Much Deeper

Even if you think you can make it through a few inches of floodwater, you have to be aware of your surroundings. We live in Houston, and many of our neighbors have huge trucks. We have all seen people in big trucks driving recklessly through flooded streets. They spray water over other vehicles and create wakes that can raise water for other cars. You will also be making your wake. So, even if you have walked through floodwater and determined it is only a few inches deep and should be safe to pass, you could be wrong. Even a single passing vehicle could dramatically change that. 

If Your Vehicle Gets Submerged, You May Be Stuck

If you drive into water that covers even part of your doors, you may be stuck in the vehicle. The water pressure on the doors can make them impossible to open. You may think you can rely on your windows to crawl out of the car. However, if water ruins your electric system, you may not be able to get windows to go down.  

Even if you get out of the vehicle and into the water, you may still be in danger. Floodwaters that are deep and fast enough to submerge your car can be deadly.  

You Do Not Know What Is Under the Water

Even if you have driven that route hundreds of times, you have no idea what floodwaters might conceal. Floodwaters carry debris. That means that water could be hiding large branches and other hazards that could injure your vehicle. Floodwaters can also cause tremendous damage. You have no idea if the road is damaged or is hiding potholes or even sinkholes.  

You Risk Electrocution

Most people do not think about this, but your car has electronics and a powerful battery. If water gets inside your car, damaged electronics could electrocute you. However, the real risk of electrocution comes from downed or broken wires in the surrounding water. 


Now that you know how dangerous it can be to drive into floodwater, we need to talk about what can happen to your car. Even vehicles that seem to make it through floodwaters without apparent damage can develop severe flood-related issues. 

Hydro-Locked Engines

One of the most severe issues you face is a hydro-locked engine. Both diesel and gasoline engines need fresh air to burn fuel. If you get water near your air intake, it can pull water into the engine. That can cause your engine to seize.  

How much damage does a hydro-lock do to your engine? It depends on your engine, how much water got into it, and how quickly you address the problem. Usually, you will have a significant repair bill. Sometimes, you will have to replace your whole engine.

Many people mistakenly believe that they have to submerge the engine to risk hydro-lock. That is simply not true. If you get water in your engine compartment, it can get into your air intake. For most vehicles, even six inches of water can make that happen.  


It Can Fry Your Electronics

Modern vehicles have complex electrical systems. Exposure to floodwater can immediately damage some of your electronics. However, even if you do not notice immediate damage, you could still have problems. Prolonged water exposure can corrode electrical connections and destroy electrical wires. Your car might seem fine right after a flood but suffer extensive long-term damage.  

Fluid Contamination

Your vehicle has a lot of fluids that help it run safely and efficiently. Most cars use the following liquids to function optimally: 

·      Oil

·      Brake fluid

·      Radiator fluid

·      Power steering fluid

·      Differential fluid

·      Transmission oil

If you get water in your engine compartment, you risk these fluids getting into various systems. The fixes for those issues vary. You can flush and clean a system and replace the liquid in some instances, which may be a several-hundred dollar repair. In other cases, contamination means having to replace expensive components. 


Yes, your car is exposed to water constantly. Vehicles can drive in the rain and run through car washes without damage. However, vehicles should not take in water from the underside. They have unprotected metal components and connectors. Driving through floodwaters can lead to corrosion and rust on your car. 

Mold, Mildew, Etc. 

Likewise, liquids should not soak your car’s interior. Having any extensive water exposure puts you at risk of mold and mildew. On top of that, flood water is filthy. People picture a river of water when they think of floods. However, floodwaters pick up chemicals, animal waste, debris, and other hazards. They are muddy, disgusting, and often full of harmful bacteria. If those get in your vehicle, it can be impossible to get clean. Your car will smell and could develop severe mold or mildew issues. 


What Do I Do If I Have Driven Through Flood Water? 

We want to stress the slogan, “Don’t drown, turn around.” If you think you are about to drive into floodwaters, turn around instead of risking yourself or your vehicle. 

However, what do you do next if you ignore that advice or get caught in a flash flood? 

Bring it into Sullivan’s Truck and Auto Repair even if you think your vehicle seems fine. We can thoroughly inspect the entire vehicle. If we see problems, we can perform any maintenance and repairs you need and do our best to mitigate any potential flood damage.  

If you are in the market for a used car, keep floods in mind. Many people with hidden flood damage try to sell their vehicles after a flood. We can give the car a pre-purchase inspection to keep you from buying the problems that can come with a flooded vehicle.