Can a Car Exhaust Go Underwater? [Explained]

If you’ve ever been stuck in the middle of a flooded street, chances are your car’s exhaust pipe was underwater too. Should this be a concern? What is the risk to my vehicle? Can I still drive it afterward

So, the answer to the question “Can a car exhaust go underwater”?, is YES. It turns out that if your car’s engine and exhaust system are well-designed, there will be no damage from being submerged in water for a short period of time. In fact, most modern cars have an air supply tube called an “air induction” that prevents water from entering the engine compartment during floods . This tube comes up through the hood and into the air filter box on top of the engine compartment where it connects to one end of a hose attached to another tube coming down below with openings at both ends.

If your exhaust pipe is submerged in water, the water will not be able to flow in the pipe.

This is because water molecules have a strong tendency to stick together. The exhaust gases which consist of tiny particles travel fast enough to push water out of their way as they pass by, causing them to be transmitted through the pipe into the atmosphere.

The holes in your exhaust system are very small in comparison to the volume of exhaust gases passing through them. This causes the pressure in your exhaust system to be much greater than that of the water outside which helps push the exhaust gas out rather than allowing water into it.

In simple terms, this is how the pressure inside your exhaust pipe will keep flooding from occurring.

Although, it is possible for exhaust gases to push water out of their way through the holes in your exhaust system, which will then cause a vacuum behind the gas particles forcing water into your exhaust.

This causes you to have excess water in your exhaust and you can tell if you do because you will hear a hissing sound coming from the exhaust pipe followed by white smoke. Also, your vehicle may lose power as a result of this condition.

Table of Contents

What are the dangers of an underwater car exhaust?

An underwater car exhaust can suck water into your engine and you could potentially sink in the middle of a lake. If you are to run at too high a speed you may end up with water inside your air intake. If you go really fast you might cause a suction effect which can get bigger as you go faster.

Does putting water in your exhaust make it louder?

No, you may experience a very slight increase in volume as you initially add water to your exhaust system but this will soon revert back to normal.

Why you should never add water to your exhaust system?

  1. The inside of your exhaust pipe is very hot, adding water will cause it to boil which creates a lot of pressure in the system, you don’t want this
  2. Water is an excellent conductor of heat energy and you are encouraging more heat into your muffler therefore, causing potential damage to it.

Why do people put water in their exhausts?

Some people will put water in their exhaust system because they believe it makes you go faster, this is far from the truth.

There has been an episode of Top Gear where you can clearly see that adding water to your exhaust system doesn’t give you any extra power.

Can you clean your exhaust with water?

Yes, you can clean your exhaust with water.

  1. You need a bucket of cold water and a sponge for this to work well
  2. You also need soap preferably dishwashing detergent, you will find it in any grocery store or supermarket near the cleaning products section
  3. You will want to mix some soapy water into the bucket then put the dirty end of the sponge you used to clean the grill into it.
  4. Scrub away at the exhaust pipe and see all of that nasty black soot being scrubbed off your pipes.

How deep can you go with a car exhaust submerged underwater?

You’ve probably seen videos of car exhausts being submerged underwater on youtube. But you might be wondering how deep you can go with a car exhaust underwater.

With a little effort, you should be able to submerge your vehicle under 15 feet of water without damaging your engine.

One way you could tell you are getting close to 15 feet is if you have to put more effort into pushing the vehicle down further below the surface of the water when you start pushing the car into the water.

The reason you can go so deep is that you have more than 2 feet of clearance above your exhaust pipe and you do not have to push the vehicle down far into the water for it to be completely underwater.

Do you need to clean your car exhaust if you submerge it underwater?

You do not need to clean your car exhaust, but you might need to unclog it if you submerge long dirt or mud-filled pipe in water for too long.

You may wonder why you would need to clean the exhaust in the first place, or whether you should worry about it being clogged.  


As you can see you can submerge your car exhaust underwater without any problems, you just need to make sure you don’t push the vehicle down too deep into the water.

It is not recommended that you go deeper than 15 feet with an exposed exhaust pipe. The main reason for this is that higher pressure will build within your muffler and you could experience problems with this which you will probably not be able to fix on your own.


Expert advice: Driving through flood water

How to Clean Your Exhaust System – Inside and Out