Is An Exhaust Leak Bad?

Is An Exhaust Leak Bad?

Cars can be an essential part of our everyday lives. Due to the fact that we might need them to get to and from work, or even to get the groceries or see our loved ones – we want to ensure that our cars are running smoothly.

The problem is though that cars often break down or need minor repairs, and one common area is the exhaust. 

If you’ve noticed an exhaust leak – it could be a bad sign, threatening both your car’s and your own health! 

This guide will explain everything you need to know. So, if you’ve noticed your car’s exhaust leaking recently – here’s some things to bear in mind. 

What Causes An Exhaust Leak?

Exhaust leaks can occur for a few different reasons, however the two most common reasons are simply due to wear and tear over time and a foreign object hitting the exhaust at speed.

Due to how exhausts work, running your car can cause the temperatures to wildly change from extremely hot to extremely cold, which can cause expansion and contraction.

Over time, this can lead to small leaks heading to the manifold gasket and this can seep out as a leak. Secondly, depending on the age of your car and how it has been stored – rust can cause an exhaust to leak over time. 

When rust takes over, it can significantly reduce the integrity of the exhaust, which in turn can lead the exhaust to have small or even large gaps. 

These gaps can cause a loud and irritating noise, almost like you’re driving a jet! Another reason you might hear such a sound is, as we mentioned, a foreign object hitting the exhaust. 

This is common in areas with loose debris on the roads, such as near the coast. Small stones can hit your exhaust at speed and cause small holes – which can cause this irritating sound, and also mean you have an exhaust leak.

Why An Exhaust Leak Can Be Bad 

Why An Exhaust Leak Can Be Bad 

Below, we explain why an exhaust leak can have detrimental effects on your car and potentially to you and your passengers. 

Dangerous Exhaust Fumes 

If you can smell the fumes coming from your exhaust, this can mean that the dangerous fumes are leaking into your car’s cabin. 

Cars are designed in such a way that the dangerous fumes are meant to escape out of the rear of the vehicle on the outside – which critically are away from the driver and the passengers within the vehicle.

These fumes are then released into the atmosphere outside. While the ethical debate on this continues to rage on, the crucial point is that the fumes are outside – where oxygen is abundant.

Exhaust fumes are a problem, but carbon monoxide is one of the most deadly byproducts of combustion – and if these fumes are not escaping, and are instead traveling into the vehicle, you can be exposed to deadly carbon monoxide poisoning.

They often refer to carbon monoxide as the silent killer, because typically it cannot be detected. However, the fumes from your car exhaust are often easily detectable. 

It’s extremely important that you open your windows and pull over as soon as possible to contact a professional for assistance as soon as possible if you notice dangerous exhaust fumes in your car.

A Problem With The Catalytic Converter 

Exhaust leakages can actually lead to significant problems to your catalytic converter by drawing oxygen into the exhaust system.

The oxygen sensors in your car will read this extra oxygen as a lean condition and as a result, it will add more gas to the mixture for combustion – and this can mean that there is actually insufficient air present to burn the gas.

While this might not sound like a huge problem, it can over time cause interior substrate to become damaged and the unit can become clogged. 

To put it simply – a leaking exhaust can all but destroy your catalytic converter (see also ‘How Long Do Catalytic Converters Last?‘) and this is a key part of your car. In fact, it can be the most costly to repair – if it is even possible to begin with. 

If caught early enough, a professional should be able to fix the problem before it gets too bad. 

Engine Damage 

Another huge problem with exhaust leakages is the fact that the fumes and harmful chemicals can become trapped and block the valves that transfer heat away from the engine (see also ‘How Long Do Radiators Last?‘). 

Over time, this can mean that the engine is unable to cool itself during operation and you will end up with serious internal engine damage (see also ‘What is Rod Knock?‘). 

This can also be one of the most costly damages to occur to your vehicle, so once again you should try to contact a professional as soon as you can to try to curtail any potentially huge damages. 

Excessive Fuel Use 

Another possible threat from a leaky exhaust is the potential that your car will need extra gas, more than it needed before. 

While this is not always the case – it’s worth noting because you could end up spending more money on gas and repairs, or even run the risk of breaking down in a dangerous area. 

Signs Of An Exhaust Leak

The most common signs of an exhaust leak are:

  • Loud sound similar to a plane 
  • Poor gas efficiency 
  • Rattling sounds 
  • Popping or hissing noises 
  • Smell of gas 
  • Smell of burning 
  • The check engine light illuminates (see also ‘What Does No Engine Brake Mean?‘)
  • You can see a hole or gap in the exhaust pipe
  • The car’s performance is significantly worse than before 

What To Do 

If you notice any of the above symptoms, ensure you contact a professional immediately for a repair to your exhaust or a replacement exhaust. Limit your driving before then.

Final Thoughts 

An exhaust leak can be bad, but as long as you get it seen to quickly – you can avoid potentially astronomical costs and health hazards. 

Dave Oliver

Dave Oliver is a seasoned car modification expert with over twenty years of experience in the field. His knowledge spans from restoring vintage models to implementing the latest customization technologies. He brings his passion and expertise to life through informative and engaging articles.

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