Common Causes of a Car Leaking Water and What it Means

car leaking water onto pavement

It can be worrisome to see a car leaking water from its tailpipe, but there's no cause for alarm. There are a number of harmless reasons for water coming out of exhaust pipes, in addition to some more serious causes. Here's what to look for.

Why Is My Car Leaking Water?

car with water underneath

Engine Combustion Water Condensation

As combustion takes place in your car’s engine, a mixture of water and carbon dioxide is created.

When the engine has cooled and any exhaust gasses exit the combustion chamber, that condensation of water and carbon dioxide becomes much more noticeable, and in a moment like that one, you're more likely to see water dripping from your car's exhaust pipe.

Catalytic Converter Byproduct

The purpose of your car’s catalytic converter is to convert otherwise harmful emissions into things that are less harmful before they exit the exhaust. One of the many byproducts that this vehicle component produces is a small amount of water vapor.

Hot Engine Condensation

You may notice water in your tailpipe when the car's engine first heats up. This happens because while your engine heats up, the exhaust system produces heat as well, which presents as vapor in your tailpipe.

Dangerous Exhaust Pipe Leaking

car leaking green fluid

When water is still running from your exhaust after your car has been running for a significant period of time, you should be concerned.

Likewise, if more than a few drops are coming out, you might have a problem.

If the substance coming out isn't completely clear, it could be a coolant fluid, in which case you should check your antifreeze and oil systems to look for leaks in tubes or connectors. If you see a green/white substance, you could have a situation where your car's oil is mixing with its coolant.

This combination is a serious problem because degraded oil can't properly lubricate your engine. Take your car in for repairs, or find the gasket, head, or tube issue and fix it before you get back on the road.

Muffler vs Exhaust

As previously mentioned, an exhaust pipe, which is part of the larger exhaust system, is found underneath the back of your car. The exhaust pipe expels things from the car like gases and vapors. These are supposed to exit the vehicle. If the pipe is leaking, however, it can affect your engine performance.

Mufflers are also located on the rear, bottom section of your car. The purpose of a muffler is to dampen engine noises, which is why muffles are often referred to as silencers. While the exhaust helps expel gas and unwanted debris, the muffler controls the noise level associated with that process.

A muffler can last anywhere from 40,000 to 80,000 miles on a car. Depending on how much you drive, this can be a few years or much less time.

Vehicles frequently driven in poor conditions or near the coast may need to have their muffler replaced more frequently as they can be affected by salt from the air or snow with salt on the ground.

If your muffler is broken, you should replace it as a broken or damaged muffler can make your entire exhaust system less effective. It will cause your car to produce a larger amount of emissions, and therefore decrease the vehicle's fuel economy.

exhaust pipes dripping water

Annual Maintenance

Whenever there is an issue with your car, you should fix it immediately. Many fixes can be done yourself with just a little bit of knowledge or research.

Beyond just fixing problems as they arise, though, you should also take steps to maintain your car properly and prevent issues from happening in the first place.

Regular maintenance can also make your car last longer, which is ideal for everyone because of how expensive cars are and how important it is for your vehicle to be both safe and reliable.

One thing you should check regularly is oil and coolant levels. Do so when your car is off and your engine has had time to cool off completely. Low levels of either can cause overheating and other engine issues.

You also need to get oil changes. Motor oil helps to lubricate your vehicle. It also keeps the engine cool down and helps to reduce how quickly wear and tear affects your vehicle. This is why you need to take your car in for regular oil changes.

How often you need to change your oil will depend on how much you drive and the recommendations for your specific vehicle. Most cars need to have an oil change every three to six months.

Transmission fluid also acts as a lubricant. It keeps pieces of the transmission lubricated. Low transmission fluid levels can have costly effects on your car so make sure you also check this on occasion.

A lot of people forget to do this unless the light on their dashboard comes on, but it's important to check your tire pressure on occasion, especially if you are about to go on a big road trip or have driven on hard terrain. Make sure to check for the specific pressure your car's make and model calls for.

You should also make it a habit to occasionally rotate your tires. Tires do not always wear evenly so rotating them helps to spread the wear and tear and prevents one tire from going out completely while the other three are still fine.

You will also need to change out your tires on occasion. If you live in an area with a lot of snow and dangerous driving conditions, you may also want to put on winter/snow tires ahead of the first snowfall of the year. Winter tires are designed to handle the snow better than traditional tires.

Make sure to also check your air filter. The air filter regulates air flow in your engine and keeps out dirt. A properly working air filter will ensure that your vehicle is fuel-efficient and will decrease your emissions.

Your windshield wiper fluid should also be checked semi-regularly. Luckily, it is easy to tell if you are out of wiper fluid. You can still drive without the fluid but it is better to fill it when it is running low. Windshield wiper fluid is cheap and can be purchased at most gas stations. It is something you can easily add to your vehicle yourself.

Windshield wipers should also be replaced occasionally. The more you use them, the more frequently you will need to replace them. If you live in an area that gets a lot of snow, they will be subject to greater wear and tear than an area that does not even get regular rain. This is a relatively cheap replacement and a project you can do yourself fairly easily.

You should also check on your car battery on occasion, especially if you are in an area with extreme temperature fluctuations. This can affect the battery. It would be awful if you got to your car and it didn't start. Checking on the battery decreases the chances of this happening.

You should also check the coolant levels ahead of cold weather. The coolant or antifreeze keeps your engine from freezing during cold weather.

Make sure to also clean your car regularly. Doing so will allow you to spot issues early on as you are viewing the car and prevent rust from forming anywhere which can negatively impact the performance of your vehicle.

This may sound like a lot, but by doing some basic maintenance you will ensure your car will last a long time and lower the risk of costly repairs. In the long run, these investments can save you a lot of money on repairs or a replacement vehicle.

Bottom Line

Water leaking from the exhaust pipe is usually nothing unless it’s coupled with other stranger malfunctions, and the brief circumstances under which you see water dripping from the exhaust are likely negligible.