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4 Exhaust Smells and What They Mean

When your car exhaust starts producing some funny smells, you know that something is not right. While it might seem trivial, a damaged exhaust can cause serious issues, affecting your engine's power and your car's overall performance. The problem with exhaust smells is that there is no one definitive cause of a smelly exhaust. It might manifest itself as a nasty rotten egg smell, or other times, a sweet smell, all of which can indicate a different problem. To help you better understand your particular situation, check out these typical exhaust smells and what they can indicate.

exhaust system functioning properly after car maintenance

1. A Sweet Smell

While sweet-smelling fumes from your exhaust might seem pleasant, they usually indicate an underlying issue. In most cases, it is due to a broken or damaged head gasket, which, in turn, leads to hot coolant leaking into your exhaust. On contacting your engine, coolant emits billowing clouds of white smoke that come out of the tailpipe. If left unattended, a coolant leak might cause your engine to overheat.

2. Smell of Rotten Eggs or Sulfur

Another smell you might experience is the smell of rotten eggs or sulfur. This probably means that your catalytic converter has been damaged. As your engine burns fuel, harmful gases such as hydrogen sulfide are produced. These gases are passed through a catalytic converter, which transforms them into less dangerous forms. Therefore, if your catalytic converter is malfunctioning, this conversion may not occur, resulting in the sulfur odor. A damaged catalytic converter will not only make your car smell bad, but it will also limit performance, raise pollutants, and cause it to fail emissions testing.

3. The Smell of Gasoline

If your car's exhaust smells like gasoline, it's likely due to an excessively rich air/fuel ratio. This can mean one of two things. Either too much fuel is entering the combustion, or not enough air is getting in. This can be caused by various issues, including damaged and leaking fuel injectors, a blocked air filter, or a defective mass airflow sensor. Other than the smell, you might also observe black smoke coming from the tailpipe.

4. Your Car’s Regular Exhaust Smell

It is important to note that your exhaust also emits its own smell. Normally, this would be kind of musty and smoky and should be pretty easy to distinguish from an otherwise unusual smell. However, if you can smell the exhaust even when within your vehicle's interior, you might be having an exhaust leak. Since exhaust fumes contain carbon monoxide, this can be a major problem that should be handled right away.

Contact Our Mechanics

At Custom Complete Automotive, we are proud to provide quality, affordable exhaust repair services to ensure your car functions properly and safely. To learn more about our exhaust repair services, contact our team today!

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About the Author
Eric Riddles

Eric Riddles is an ASE Certified Master Automobile Technician who has been working as an auto mechanic since 1998 and originally joined the team at Custom Complete Automotive in 2005. Eric has numerous certifications in various aspects of car repair and spent 10 years training the next generation of auto technicians at a local high school Auto Shop classroom.

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