Some Causes of Smells Coming From Your Car

5 Things Your Nose Can Tell You About Your Car

Besides that new car smell, there are fairly few odors you experience in or around your car that are pleasant. Your nose knows when something is foul or amiss. Some smells are pretty telltale of a certain condition, while others might present a little more mystery in need of investigation. Here are five odors that are indicators of potential problems with your car.

Hot or Burned Oil

The smell of hot or burned motor oil could mean that a gasket or seal is failing. This lets engine oil leak onto hot engine parts. Additionally, a leaky transmission seal can cause oil to spray all over the engine, including the manifold. These hot engine parts burn off the oil, creating bluish white smoke that wafts from under the hood.

The first thing you should do is check the oil to make sure it is at the correct level and that it’s clean. Small leaks often become bigger leaks, so check under the car, on the pavement where you park, and around the engine for signs of leaks. If your car is running low on oil, the engine can overheat and burn whatever oil is remaining.

If the burned oil smell is coming from the tailpipe (bluish white smoke), it is a symptom of oil leaking into the combustion chamber, which means it is getting into your exhaust system. The oil is burned in the combustion process with the air and fuel mixture, and pushed out through the exhaust system. The exhaust system is one of the hottest systems in your car, dealing with the noxious byproducts and fumes of the internal combustion engine banging away under the hood. If oil leaks into the either the combustion or exhaust system, it is going to be burned. This is usually a sign of an old, worn out engine in need of some serious repair and regular maintenance.

GasolineAAMCO Minnesota Vehicle Bad Smells

If you smell gasoline, like when it’s pumped at the gas station, inside or outside the car, you should take special care to identify the source. It is likely a sign of a gas leak in the fuel line or fuel injection system (if your car has one). A leak in the fuel tank vent hose oftentimes is the culprit behind gasoline odors inside the car, especially after filling the gas tank. At worst, there could be a leak in the gas tank itself.

In older pre-1980’s cars, the smell of gasoline can occur after the car has been turned off due to fuel afterboil. This is often normal and results when a small amount of gasoline continues to burn in the carburetor after the engine is shut down.

Any persistent smell of gasoline, either in the car or outside of the car such as in the garage, should be taken seriously. Any smell of gas fumes can indicate a fire hazard, so it should be checked immediately.

SyrupAAMCO Minnesota Bad Smelling Car

If you detect the scent of maple syrup, it probably means there is a leak in the cooling system. Cooling fluid is leaking onto hot engine parts and being burned away. If there is a leak in the cooling system, you need to check the coolant fluid level, check for leaks in the engine compartment and on the pavement in the areas you park (such as driveway or garage). Left unchecked and repaired, you will risk overheating the engine and causing major damage.

A syrup smell could also mean the engine coolant is boiling after you have turned off the engine. This is due to the inability of the cooling system to dissipate engine heat, so the engine remains extremely hot for an extended time even after it has stopped. If you decide to investigate, wait until the engine has cooled off! Never remove the radiator cap while the engine is running or is still hot. It will cause a massive blow off of superheated fluid that could cause serious injury.

Rotten Eggs or Sulfur

This wonderful stench means your car is in need of a checkup and that the catalytic converter is having some serious issues. The catalytic converter is in the car’s exhaust system and is supposed to convert noxious hydrogen sulfide to sulfur dioxide in the exhaust fumes before they exit the tailpipe. If this is not happening, it means that your engine needs more than just a tune-up, and the catalytic converter could completely overheat and fail, leading to costly repairs.

Burned PaperBad Smelling Exhaust Fumes

If you smell something like burned paper, it could meant that your clutch is overheating. If you’re riding the clutch pedal, it creates excess friction between the clutch facing and slips. The material between these surfaces is made of a paper compound, which gives it its familiar smell.

The smell of burning paper could also mean your brakes are overheating. Riding your brakes, such as when coming down a hill or mountain, creates unnecessary friction and excess heat on your brake pads. You might also have a seized up brake piston, resulting in a “dragging brake.” Or it could be that you just left your parking brake on. In some cars it is easy to forget and actually drive with the handbrake still engaged.


AAMCO Minnesota Can Help Sniff Out and Fix Problems With Your Car

We realize that in order for one to understand some of this, you must know what the “smells like” really smells like. If you’ve never had maple syrup – get thee to a pancake house now – you’ll likely not know what to sniff for. Whatever the smell, if it’s not new car or the scent of that air freshener you just bought to battle the gym socks and mildew in your car’s air filtration and circulation system, then you should come to AAMCO Minnesota for a multi-point diagnostic inspection.

Visit an AAMCO Minnesota transmission repair and total car care center near you. When issues arise and you need affordable, honest auto repair, schedule an appointment with your locally owned and operated AAMCO Minnesota transmission and auto repair center.

If you have questions about your car’s road readiness, or about car repair and maintenance topics, AAMCO Minnesota is a great resource for expert automotive repair and maintenance information. Feel free to call or visit your local AAMCO Minnesota transmission and total car care center.

Other Articles About Car Maintenance & Repair

Sounds Your Car Makes When It Needs Repairs

My Car Rolls When I Put it in Park

Reasons Your Ride is Bumpy and Rough

I Smell Exhaust Fumes in My Car

Exhaust Smell in Your Car Can Be Due to Different Things

image - dual chrome exhaust tailpipeThe car exhaust system neutralizes the harmful fumes that come out of the engine. It is important to have your car checked out if you start to notice any odd odors or exhaust smell inside the car, as this can mean some major problems in the exhaust system or engine. If you experience any eye irritation, or you notice a smell like rotten eggs, a sweet smell or an odor of gasoline, you should have your car checked as soon as possible. Bring your car to a local AAMCO Minnesota auto shop for a complete inspection and diagnostics.

How a Car’s Exhaust System Works

Exhaust Header or Manifold

The exhaust header, or manifold, makes it easier for the engine to push exhaust gases out of the engine cylinders. In cars with fuel injection, the oxygen sensor is mounted in the exhaust header and is controlled by a computer. If the oxygen sensor is faulty or has failed, the computer can’t calculate the air/fuel ratio, so it “guesses”, which affects the engine’s performance, and this can affect many other systems as a result. If you are experiencing a strong smell of gasoline as you drive, the oxygen sensor is one of the first things to check.


image - exhaust manifold

The exhaust travels through connected pipes until if exits through the last one – the tailpipe. These interconnected pipes throughout the system do more than just help the exhaust move; they call the pollutant gases and guide them through the catalytic converter.

Catalytic Converter

The catalytic converter changes the harmful carbon monoxide and hydrocarbons to water vapor and carbon dioxide before they exit through the tailpipe. This reduces impact on the environment because the elements being emitted from the car have been broken down into more basic forms. Some converters also reduce harmful nitrogen oxides. If the odor you are smelling is that of rotten eggs, then the catalytic converter is probably failing. The rotten egg smell is because the converter is not breaking down the sulfur pollutants created by the engine. Catalytic converters can’t be repaired – they must be replaced.


The “catback” is a system of pipes between the catalytic converter and the tailpipe. These pipes, running along the bottom of the vehicle, experience a lot of wear and tear, including harsh temperatures, damage from obstacles, rough roads, and exposure to weather which can lead to rust.

Muffler & Tailpipe

An internal combustion engine runs by creating controlled explosions, so it makes a lot of noise. You don’t hear most of this noise because the muffler, if it’s doing its job, reduces (muffles) the noise to a low level as the exhaust leaves through the tailpipe. The muffler also sees a lot of wear and tear, along with the tailpipe, as they constantly go through heating and cooling between extreme temperatures.

Exhaust System Leaksimage - Mechanic and customer looking at exhaust system under car on lift

Exhaust leaks can occur in many places along the line of all the interconnected parts that make up the exhaust system. If you smell the exhaust inside the cabin of the car, the leak is possibly somewhere near the air intake vent, under the hood. The leak might be somewhere in the exhaust pipe system that runs the length of the car, or even in the muffler, but the smell won’t be so powerful. Hydrocarbons are processed in the catalytic converter, which is located behind the engine, near the exhaust manifold. So, if you smell any exhaust, it’s probably escaping, or leaking, before it reaches the converter.

Causes of Exhaust System Leaks

We’ve all seen it – a rusted muffler riddled with holes laying in the middle of the road. It fell off someone’s car, and chances are the entire exhaust system (maybe the whole car) looks like that poor, old muffler. That’s why it is important to have the underside of your car visually inspected from time to time.

Internal Corrosion

Internal corrosion is a major cause of exhaust system leaks, and is the main cause of system failure. When moisture condenses in the system, it reacts with the iron in the steel, causing acidic buildup and rust. This can eat right through the metal of the pipes, muffler, and other vital components of the exhaust system, causing leaks, structural weakness, and operational failure.

External Corrosion

External corrosion is caused by weather related road conditions. Depending on where you live, during the winter the roads might be treated with chemical deicers, salt, and sand. All of this, combined with the snow, ice, and harsh temperatures, really beats on the underside of your car – and that’s where the exhaust system is. The constant barrage of different compounds, including plain old water in the form of rain, snow, and ice, gradually eats away at the various parts of the exhaust system.

Driving Conditions and Habits

Where you live and the road conditions around you dictate much of the wear and tear on your car, particularly the exhaust system. Rough, dirt roads obviously will have a higher degree of impact on your car overall than smooth highways and city streets. Additionally, how you drive those roads is a factor. Short trips versus long hauls have different effects on your car’s systems. Whether you speed along those bumpy, dirt roads or are constantly stuck in stop-and-go traffic in the city – it all adds up to things like extreme heating and cooling, debris causing damage, and stress to systems that are not the exhaust system, but that can affect it. As mentioned earlier, if the oxygen sensor goes out, the engine will burn too much fuel, too hot, which can affect the exhaust system and cause undue heat to pass through.

Come to AAMCO Minnesota for All Your Car Repairs & Maintenance

You need an experienced automotive technician who can diagnose the problem and honestly tell you what needs to be done when something is wrong with your car.

If you have questions about your car’s exhaust, engine, transmission, repair or maintenance needs, AAMCO Minnesota can help. Stop by or call a local AAMCO Minnesota repair shop for a Multi Point Vehicle Inspection of your transmission and related systems. We can handle all your scheduled car maintenance and repairs, from brakes and oil changes to factory recommended maintenance and full transmission replacements.

Other Articles About Car Maintenance & Repair

Take the Fear Out of Transmission Repair

What is a Torque Converter?

Signs Your Alternator is Going Bad


Find a Location Near You

AAMCO Minnesota Transmission shops are locally owned and operated.

AAMCO Minneapolis

5231 West Broadway | Minneapolis, MN, 55429

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Transmission repair and rebuilds are our specialty at AAMCO Minneapolis, MN. From transmissions to brakes, radiators, air conditioning repair, tune ups, check engine light diagnosis and car maintenance, people who know call AAMCO. Our expert technicians use the latest tools and technology to diagnose and repair your vehicle. From automatic and manual transmission repairs, clutch service and replacement, and more, we know all vehicle makes and models. We back our work with the best nationwide warranty. AAMCO of Minneapolis, MN is your one-stop transmission rebuild and total car care center.

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AAMCO West St. Paul

1571 S Robert St | St Paul, MN, 55118

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AAMCO Transmissions West St. Paul is your Twin Cities one-stop shop for transmission repairs, rebuilds, and car maintenance. Our certified technicians can handle any transmission repair or rebuild, as well as auto repair and maintenance service for your vehicle. You can rely on our mechanics for automatic and manual transmission problems and rebuilds, clutch service and replacement, and more. We use modern computer diagnostics to identify transmission and engine issues so we can repair your car quickly and get you back on the road. We work on all makes and models, including 4x4s.

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AAMCO Fridley

940 Osborne Rd NE | Minneapolis, MN, 55432

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At AAMCO Fridley we believe in performing honest and affordable transmission and auto repair services. We do the job right and get you back on the road safely and reliably. From transmission repair and rebuild to brake service, air conditioning repair, tune ups, check engine light and car maintenance, AAMCO Fridley, MN is your one-stop auto mechanic. Trust AAMCO’s expert auto technicians to use the latest tools and technology to diagnose and repair your vehicle, and back it with the best nationwide warranty. At AAMCO of Fridley, Minnesota we know all vehicle makes and models and have the latest in diagnostic tools and technology. We are your total car care specialists.

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AAMCO Hopkins

10921 Excelsior Blvd #117 | 10921 Excelsior Blvd #117, MN, 55343

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At AAMCO Hopkins, MN we believe in the value of good, honest work and giving you and your family the peace of mind a safe, reliable car provides on a daily basis. From transmission repair and rebuild to brake service, air conditioning repair, auto tune ups, check engine light and car maintenance, AAMCO of Hopkins is your one-stop shop for car repairs and maintenance. Trust the transmission experts at AAMCO of Hopkins transmission repair to diagnose and repair your vehicle right the first time and back it with the best nationwide warranty. At AAMCO Hopkins transmission and car repair we know all vehicle makes and models and have the latest in diagnostic tools and technology. We are your total car care and repair specialists.

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AAMCO Maplewood

1905 County Rd D E | Maplewood, MN, 55109

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People come to AAMCO of Maplewood, MN because we care about making sure you car is running safely and reliably. You can count on us for all your automotive repairs and maintenance. From transmission repairs and rebuilds to brakes, radiators, air conditioning, check engine light and tune ups. AAMCO Maplewood transmission and auto repair technicians use the latest technology to diagnose and repair your vehicle right the first time - and we back it with the best nationwide warranty. At your local Minnesota AAMCO of Maplewood we know all vehicle makes and models - we're your one-stop total car care specialists.

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