Why does my car smell? From musty and burning to rotten egg odours


From rotten eggs to musty and dank, cars can suddenly develop odours that make you want to take the bus instead. But don’t buy that travel pass just yet, here motoring journalist and expert Pete Barden explores what the smell in your motor could mean – and how you can deal with the unwanted pong.

What do those car smells mean?Tired of driving with your window open? Here are what those car smells are and how to sort them  (Photo: Pexels.com)

That new car smell

When you buy a new car, it will have a distinctive smell that many a lot of us find to be enjoyable. This smell, known as “off-gassing”, which caused by the chemicals from the plastics, leather, fabrics, and adhesives used to make the interior of the car, along with other new parts.

While these are not immediately harmful, prolonged exposure could cause minor health problems. Some people will do their best to get rid of this new car smell, while others attempt to replicate it with air fresheners.

On the whole, though, the smell is harmless and no action will be needed.

Burning smell in the car

If you smell something burning when you're driving, it could obviously indicate a serious problem, so always make sure you park in a safe place and exit the vehicle and call 999 if it gets worse of the car’s cabin starts to fill with smoke or if you become aware of the vehicle heating up more than expected.

A less invasive burning smell could mean a burnt-out fuse, an overheating air conditioning unit, worn brake pads, or two parts of the car rubbing against each other. To prevent overheating, ensure you top up all your fluids and engine coolant before setting off on long journeys – especially in peak periods or hot weather – think school holiday trip to Cornwall. If the burning smell persists, you should visit a garage to check the vehicle for potential fire hazards.

Rubber burning smell in the car’s cabin

The smell of burning rubber inside a car could mean there’s an issue with its brakes or tyres, or it could be a sign that the clutch is slipping or not working as it should. If this persists, book yourself a slot with a mechanic.

Check the tyre tread, pressure, and get a mechanic to assess brake pads and clutch if the smell persists. If hear a squeaking or grinding from brakes, they may be dangerously worn – so get straight on to a mechanic to make the car safe.

Air conditioning pumping out a bad smell

An unpleasant smell from your air conditioning could be mean a selection of problems, including fluid leaks in the air con unit, electrical faults, or mould and bacteria growing in the system.

It is also possible you may have had an animal infestation in your vehicle if it has been left standing for a while.

Recharge the air conditioning every two years, or more if it gets heavy use, and have the system serviced by a professional who can also carry out anti-bacterial cleaning.

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Musty smell inside the car

A musty smell inside a car is a sign of water leaks, too much humidity, and other moisture problems. The musty stink can be caused by leaks in your vehicle, worn or brittle rubber seals.

It could also be caused by occupants and pets entering the car when wet.

Cleaning your car regularly and looking out for condensation and brittle rubber seals around door and window that could be the source, should get you on the way to solving this whiffy issue.

Anti-bacterial wipes and sprays will help remove any mould or bacteria that has built up and start to improve the interior aroma.

You can use a dehumidifier to remove the moisture from the air inside your car. Place the dehumidifier in the car and leave it overnight. In the morning, the moisture should have been removed, and the car should feel drier and less pongy.

Acrid burning smell in traffic

A burning smell similar to burning rubber could also indicate a damaged clutch. This happens when a driver is riding their clutch or when the clutch plate is damaged.

This acrid smell will be more common when driving in traffic, where the clutch will get a hammering. Sorting a clutch will be a job for your mechanic, and won’t be cheap.

Rotten egg smells

If you notice a rotten egg smell coming from your vehicle, then it is likely that your catalytic converter is not working properly.

This smell comes from hydrogen sulphide and is released when the converter isn’t filtering the exhaust gases correctly.

This is a serious issue and should be investigated by a professional immediately.

Not only will this impact the efficiency of your vehicle but it can also lead to a serious health issues. Hydrogen sulphide can cause eye irritation and headaches, and in larger quantities can even cause unconsciousness.

The catalytic converter is a vital component of the vehicle exhaust system – it turns the harmful exhaust gases from the engine into less harmful ones before they leave the vehicle. Therefore, if you suspect an issue with your converter, it is important to get it checked as soon as possible.

Electric car - burning smell

Electric cars are becoming increasingly popular as a more environmentally friendly alternative to traditional petrol and diesel motors.

Electric cars do not emit any exhaust fumes or emissions, which means they don’t have a traditional "car smell" associated with combustion engines.

Instead, electric cars have a distinct smell that is often described as "clean" or "sterile." This is because the electric drivetrain does not include combustible fuel or engine oil which typically cause the traditional car smell.

However, some people might also notice a faint smell that comes from the electric motor or battery. This odour is often described as a "burnt electronics" smell and is typically only noticeable when the car is first turned on or is charging. This smell is not harmful and should dissipate quickly.

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Author: Pete Barden:

Twitter: @pete_barden

Pete Barden is a qualified journalist who has written and produced for publications including The Sun (thesun.co.uk), New Statesman Media Group, Whatcar? (Whatcar.com) Stuff Magazine (Stuff.tv), Fastcar Magazine (Fastcar.co.uk), Maxim Magazine and UK broadcast stations within the Heart network (Formerly GCAP). Pete specialises in motoring and travel content, along with news and production roles. You can find out more about Pete Barden on LinkedIn.

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