Engine Maintenance

Top 5 reasons why water is coming out of exhaust

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After starting up your car, you may notice water is coming out of your tailpipe. Or rather put, water is dripping out of the exhaust – let’s be serious, it’s not exactly pouring unless you’ve been taking a stroll through the lake with your car.

And if you do notice water coming out of your exhaust it is no reason to be alarmed or panic – this is usually no big deal!

A fair mention here: obviously, if there is lots of water coming out of exhaust… like a whole cup, and your coolant constantly gets low, go to a mechanic. That really represents a problem.

Let’s explore the top reasons why water could be coming out or dripping out of your car’s exhaust.

1. Condensation makes water come out of your tailpipe

After your car’s engine has performed its internal combustion process, there will be a carbon dioxide and water mixture that forms as a result of this process.

After your engine has had some time to cool off the remaining exhaust gasses will leave the engine chamber and come out of the tailpipe. The condensation of these gases is more visible, and that means that you will be able to see some water dripping from the exhaust.

That is all there is to it, and it is a normal process. No reason to panic!

2. The Catalytic Converter can be a normal cause too!

Modern cars are equipped with a catalytic converter. This part of your exhaust is responsible for reducing the size of the toxic carbon gases emitted by your car.

This allows your car to be more environmentally friendly. But as the catalytic converter does its job, a small amount of water vapor may form as a result.

This water vapor can form little droplets that you’ll see coming out of the tailpipe. Again, this is normal. No reason to get worried or anything else.

3. Engine Heat, a normal cause

If its cold outside (like winter) or you live in a place with cold temperatures, you can actually expect to see water coming out from your exhaust.

Your engine need a little bit of time to let the oil circulate through it in order to cool the internal parts down. The moving components of the engine are going to generate a lot of heat the first couple of minutes after starting up the car. That means the exhaust system will be unusually hot too!

And because of this, water vapor is produced as the heat merges with the cold air outside. And so you may see small water drops coming out of your exhaust pipe. And if we’re touching on the subject of cold weather starting, white smoke may also come out of the tailpipe for a couple of minutes. This is perfectly normal – just wait a few minutes and it should all clear up.

4. Engine burning coolant is something you should fix

If you can obviously see that even after driving your car for some time water is still coming out of its exhaust and there’s a high amount of smoke, there is something wrong with your car.

White exhaust smoke with a sweet odor in the air, means that your engine’s burning coolant. Again, this is happening after driving for a while and not right after starting up the car.

What are the causes for your engine burning coolant?

One posibility is a head gasket leak. The role of the head gasket is to separate the engine’s combustion chambers from oil, coolant and contaminants. As it is an actual physical seal it can fail over time. It can also fail if the engine overheats (if the water pump fails for example). Luckily it is not such a big deal and it usually a simple and inexpensive fix. A quick way to tell if you’re dealing with a head gasket leak is to pop the hood, remove the oil filler cap and look underneath it – if you see a whitish/green material it means that oil is mixing with your antifreeze/water and that you might have a head gasket leak – repair this urgently as your engine is not properly lubricated.

It can also mean a cylinder or the engine block itself is cracked. This is usually tested by running a compression test on each cylinder. While it can be fixed, this is usually a sign that you might need a new engine – take your car to the shop if you suspect something like this (but staying on the article’s topic – this probably isn’t the case).

5. A faulty piston or piston rings

Usually, you can tell if a piston or its rings are the cause because you will also see smoke come out of the exhaust in addition to the water.

And if it is really bad, a burning smell will fill the interior of the cabin. You should head on to the nearest repair shop if this is the case – or even have them tow it as this might be a big problem, and you don’t want to cause more serious damage.


As you can see, some water dripping out of your car’s exhaust is usually no cause for concern and a normal phenomenon. Just keep an eye on your car oil level and your coolant levels to make sure everything is in order.

And don’t forget! Don’t touch your tailpipe or any part of the exhaust for a couple of minutes after the car has been operating or while its running – it can be hot and you might get injured!

And that’s about it! If the only thing coming out of your car’s exhaust is a bit of water, you’re in the clear – no problem.

Car enthusiast. I am dedicated to maintaining my cars as best as I can. I love things that work, and I love keeping them in a good state.

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