Why is Gas Coming Out of Exhaust Pipe? [How to Fix]

Seeing your exhaust pipe leaking gas or fuel can make you anxious. We completely understand that. But don’t panic! This problem is quite common and easy to fix.

So, why is gas coming out of exhaust pipe?

First, you need to identify whether it’s leaking gasoline or water. If your exhaust is indeed leaking gasoline, it’s often because of the rich air/fuel ratio. This means there’s an excess amount of fuel but not enough air. These problems also can happen if your fuel injector is damaged. Finally, a dirty air filter can also cause incomplete burns.

However, this is nothing but just a short preview and there’s a lot to know. So, read along if you wish to know more regarding this matter.

So, let’s not waste any more time and head right in –

Identifying the Leakage Properly

Just because your exhaust is leaking some fluid doesn’t always mean it’s gasoline. There’s a high chance of it being water. However, it can be a mixture of water and gasoline in some cases.

That’s why it’s important to pinpoint the problem first. Then we can easily take the necessary steps afterward.

Using a Fabric

The best way to identify gasoline is to light the leakage with fire. However, we do not suggest doing this while being close to your car. Because the car has a fair chance to catch fire and explode.

Take a small piece of fabric and soak it with the leakage. Get to a secure place away from your car. Light the fabric and see if it burns. If it doesn’t light on fire, it’s water.

Checking the Smoke Color

You can also identify the leakage by noticing the color of the smoke. If the emitting smoke is white, it’s water.

On the contrary, gasoline or petrol emits black smoke.

Also, a big tip would be to not sniff when too close to the exhaust pipe. It contains carbon monoxide. It has no color, odor, or taste and is extremely toxic to humans.

Why Is Gas Coming out of Exhaust Pipe? – Quick Fixes

Now that we’ve identified the liquid, it’s time to know how these problems occur. Then we can easily solve the problems.

Reason #1: Rich Air/Fuel Ratio Causes An Incomplete Combustion

One of the many reasons behind gas leakage is the rich air/fuel ratio. This happens when enough air doesn’t get in the combustion chamber. Or, there’s an excessive amount of fuel in the chamber.

Either way, this causes incomplete burn and as a result, it emits black smoke. Also, failing engine parts can also cause this problem.

Hire A Specialist

Generally, when this happens it means your car is running rich or lean. But it rarely happens. So, it is advised to hire a specialist if you don’t know what you’re doing.

Reason #2: Defective Air Filter Doesn’t Provide Enough Air

Another common reason behind incomplete burns is bad air filters. It will fail to deliver enough air to your combustion chamber.

So, now you have a proper amount of fuel but not enough air. This engine condition is called running rich.

However, this can be fixed without breaking a sweat! Also, if you have your car manual, it’s time to get it.

However, if you can’t find the manual, don’t worry! We’re going to walk you through the entire process.

Change the Air Filter

First, buy an air filter. They only cost 10-15$ and are easy to get. Then open the hood and locate the air filter. Usually, it’s a black plastic box and there’s a giant hose attached to it.

Now just unclip the box and you’ll probably see a dirty air filter. Take it out and see for yourself whether it’s dirty or not.

Now place the new air filter in the box! Please, make sure it sits well in the box. Also, don’t forget to close the box.

And give your car a try and see if it’s still emitting black smoke.

Speaking of air filters, these are some of our recommended picks –

Now, you can quickly grab either one and start working!

Reason #3: Damaged Fuel Injector Restricting Fuel Line

If fixing the air filter doesn’t fix your gas problem, it’s bad news. You’re probably facing a serious problem which is going to cost you a little bit.

It’s most likely a fuel injector problem. This also means a fuel regulator could be stuck or there’s a restricted fuel line. It takes around $60 -$120 to fix a restricted fuel line.

Hire a Mechanic or Go To the Dealer

All of these problems require an engine mechanic to fix. In some cases, the mechanic may suggest a new gas tank. A new gas tank will cost you around $300-$400.

If you have a service warranty, don’t forget to claim it. Just take your vehicle to a dealership and they’ll fix your problem.

So, don’t hesitate to seek professional help. The faster you fix the problem, the better it is for your car. The problem can get way worse than this which you definitely want to avoid.

Frequently Asked Questions

Q: Is it normal for liquid to come out of exhaust?

Ans: Yes. When the engine is cooling down, condensation of water can be seen. This creates a lot of water and you will see them dripping out of the exhaust. This is totally normal and you don’t have to go to a mechanic.

Q: What comes out of exhaust pipes?

Ans: An engine creates a lot of gasses and they are released through an exhaust pipe. They are carbon dioxide (CO2), Nitrogen Oxide (NO), and carbon monoxide (CO).

Q: Why does white smoke and water come out of my exhaust pipe?

Ans: It’s because of the engine’s coolant. Since the coolant liquid has water in it, it creates a white smoke while evaporating. Then it exits through the tailpipe.

Conclusion

This is all we could provide on this matter. Hopefully, now you know what’s causing the problem.

However, you still may not understand why is gas coming out of exhaust pipe. In that case, it’s better to leave it to the pros.
Let us know if this has helped you. Good luck!

Author
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Rob Dahm

My name is Rob Dham. I am the founder & managing editor of greaseandgears.com. I am trying to offer invaluable insights and solutions to everyday vehicle-related challenges.