Car smells explained: Causes and how to fix them

Car smells like burning rubber

The unmistakable smell of burning rubber indicates that you may be dealing with an engine, braking system, or tyre issue. Belts, hoses, or tyres slipping against hot surfaces can create this distinctive odour.

If you drive a manual car, the burning smell may also be caused by a faulty clutch. In some cases, burning rubber smells are accompanied by the sound of squeaking brakes.

How to fix a burning rubber smell in your car

• Allow your car to cool down, then check your tyre tread depth and pressure.
• For your car to be roadworthy, the tread on each tyre must be a minimum of 1.6mm. However, studies have shown that performance is compromised when tyres are worn past 3mm. So, it’s advisable to replace them if they are worn past this point.
• It’s also important to check your brake pads to determine the source of the burning smell.
• If the smell persists, take your car to a mechanic for diagnosis as soon as you can.

Car smells like burning oil

If you notice a burning oil smell, this could be down to a low oil level, or an oil leak. You should investigate this smell promptly, as if left unchecked, an oil leak could seriously damage your car – and may even cause an engine fire.

How to fix a burning oil smell in your car

• Check the oil level with a dipstick.
• Check around the car for oil leaks.
• If your oil levels are low, book an oil change at your earliest convenience.
• If you suspect there is an oil leak, take your car to a mechanic promptly. Ignoring an oil leak can cause engine damage, compromise handling, and increase the risk of fire.
• If there is no oil leak, and the level is correct, you could be using the wrong type of oil for your car. A mechanic can confirm whether this is the case.
• After the mechanic has checked your car, you may notice that the oil smell persists. You should be able to remove what’s left of the burning oil smell by cleaning your car with a mixture of soapy water and baking soda – or neutralising the odour by placing fragrances such as cinnamon sticks and orange peels inside your car.

Car smells like burning plastic

A burning plastic odour may indicate that your brake pads are worn. Friction may occur when the brake pads and rotors aren’t in alignment – and this produces the burning smell.

If left unchecked, this can create more friction within the car’s internal wiring - and may eventually result in an engine fire or explosion.

Other potential causes include plastic insulation melting after coming into contact with a hot engine, exposed wiring, an overheating A/C compressor – and a damaged alternator.

How to fix a burning plastic smell in your car

If you notice a burning plastic smell, your first step should be to take your car to a mechanic for diagnosis.

Once they have resolved the issue, traces of the smell may remain. Potential solutions include:

• Airing out the vehicle by opening all the windows. This will be particularly effective on a breezy day.
• Boiling cinnamon sticks, then placing them in a cup to clear the air inside your vehicle.
• Placing containers of baking soda in your car. This can help to absorb the odour.
• Leaving a small bowl of coffee grounds in your car to soak up the smoky smell.

Car smells like rotten eggs

Rotten egg is a particularly pungent smell – and can also indicate a serious issue with your vehicle. Possible causes include a faulty catalytic converter, fuel filter, fuel pressure regulator, or fuel injector - and old transmission fluid.

If you notice this smell, you should take your car to a mechanic for diagnosis as soon as possible.

How to fix a rotten egg smell in your car

In most cases, identifying the source of the smell, and then replacing the offending component should get rid of the smell. If it persists, here are a few solutions you can try:

• Steam your car’s upholstery.
• Use an odour eliminator in place of traditional air freshener.
• Vacuum the interior.
• Sprinkle baking soda throughout the interior, then leave it in for a few hours, before cleaning it up with a vacuum. This should help to absorb the smell.

Car smells like burning electrical components

Faulty wiring, overheating electrical components, or short circuiting can produce a distinctive burning smell in your car. You may also notice sparks, stalling, unusual noises, and flickering electrics.

If you notice any of the issues highlighted above, take your car to a mechanic immediately. Don’t ignore this smell, as the electrical system could sustain serious damage, or the car may even catch fire.

Important: If you notice smoke, exit your car immediately, then call the emergency services.

How to fix a burning electrical smell in your car

Once the fault has been resolved, try the following solutions to get rid of the lingering smell:

• Air out the car by opening the windows.
• Wipe down the seats and interior using dryer sheets.
• Use an interior car shampoo to clean the steering wheel, gearstick, doors, plastics, and other interior surfaces.
• Using an equal mixture of white vinegar and warm water, wipe down the hard interior surfaces with a cloth.

Car smells like sweet syrup

If you notice a sweet, syrupy aroma, a coolant leak is the likely culprit. Coolant contains ethylene glycol – a sweet-smelling chemical compound. When there is a leak in the cooling system, coolant travels through your car’s undercarriage and leaks onto the road, creating a sweet and potent scent.

Driving with a cooling system leak increases the risk of overheating. There is also a danger that pets and wildlife will ingest toxic coolant, as they are attracted to the sweet smell. Therefore, you should clean up any leaks promptly and take your car to a mechanic at the earliest opportunity.

How to fix a sweet syrup smell in your car

Once the coolant leak has been resolved, try the following solutions.

• Rinse the area where the leak occurred.
• Try airing out the car by opening the windows and running the heater or A/C.
• Deep clean the carpets and upholstery with a cleaning solution (e.g. baking soda, shampoo, or vinegar).

Car smells like petrol

You may notice a slight petrol smell just after you’ve filled up your car, but this should disappear after a few minutes. It’s also important to check that you’ve secured the petrol cap after filling up.

However, if the smell persists, this could be down to fuel leaking from your fuel system into another part of your car.

This issue is relatively rare in modern cars, thanks to their advanced fuel injectors and safety technology. However, fuel fumes can be extremely dangerous. So, stop driving – and arrange for your car to be taken to a mechanic if you notice a lingering fuel smell.

How to fix a petrol smell in your car

Once the leak has been resolved, here are a few solutions you can try to get rid of a stubborn petrol smell:

• Create an equal mixture of water, soda, and vinegar.
• Dip a rag in the solution and dab onto the affected area.
• Allow it to sit for half an hour.
• Dispose of the rag after use.
• Rub coffee grounds into the affected area, wait around a week, and then vacuum the area.
• If the smell persists, try shampooing the area.

Mould and mildew smells

When the mild weather arrives, you may notice an odd smell after activating the A/C for a first time in a while. Over time, air-conditioning systems gradually accumulate dust and debris, which can lead to unpleasant odours circulating in the cabin.

Moisture within the system can cause mould and mildew to develop, which reduces the air quality and creates an irksome smell.

How to fix a mouldy or mildew smell in your car

• To clean the A/C, try running it to dry it out, then clean it with antibacterial wipes.
• If the smell persists, visit your mechanic and request a system recharge.

Sour-smelling exhaust

Whilst your car is running, it produces various gases, which are then expelled through the exhaust system. If you notice a sour smell coming from the exhaust, there may be a leak within the exhaust system.

How to fix a sour exhaust smell in your car

If you notice a sour exhaust smell, pull over immediately, and turn off the engine. Arrange for your car to be towed to a garage. It isn’t safe to continue driving, as if the gases aren’t being expelled properly, this could lead to dangerous carbon monoxide levels in your car.

In some cases, you may require a new catalytic converter. Once replaced, the smell should improve.

Burning hair or burning carpet smells

A smell like burning hair or carpet can be indicative of brake trouble. Brakes may overheat when they are overused or used forcefully. Such a smell may occur when driving down a steep hill, or sometimes, during normal driving.

How to fix a burning hair or burning carpet smell in your car

You should act quickly when you notice this smell. When brakes overheat, they stop working correctly. Use a low gear - and switch to engine braking when travelling downhill to reduce the strain on your brakes. Worn brake pads could also be the culprit.

Take your car to a mechanic immediately to prevent serious damage. Having the offending component(s) repaired or replaced should get rid of the smell.

Car smells like exhaust fumes in the cabin

Common causes of an exhaust fume smell in your cabin include:

• An exhaust leak behind the catalytic converter.
• Worn window seals.
• The catalytic converter is responsible for filtering out harmful gases. So, if you are a victim of catalytic converter theft, these gases may find their way into the cabin.

If you notice the smell of exhaust fumes in your cabin, arrange for your car to be towed to a mechanic for diagnosis and repairs. You should not drive with exhaust fumes circulating in the cabin. These fumes contain harmful compounds such as carbon monoxide, which can be fatal if you’re overexposed.

How to fix an exhaust fumes smell in your car

Once your mechanic has addressed the issue that caused exhaust fumes to enter your cabin, the smell should improve. If there is still a lingering odour, you should be able to neutralise it by trying the following remedies:

• Use an ozone generator to purify the interior air.
• Shampoo the carpet and upholstery.
• Place fragrances such as cinnamon sticks and orange peels in your car.

How to prevent bad car smells

• Use air fresheners.
• Clean your car (inside and out) on a regular basis.
• Consider using a professional valet service if smells persist.
• Keep anti-bacterial wipes and other cleaning products in the glove compartment to proactively tackle spills and stains.
• Clear any unnecessary items out of your car on a regular basis.
• Don’t leave wet or dirty clothes in your car overnight.
• Open the windows regularly to allow fresh air to circulate.
• Top up all fluids as required.
• Regularly use your air-conditioning system to ensure it’s working correctly.
• Try aromatic solutions such as orange peels, cinnamon sticks, and coffee grounds to tackle odours.
• Keep up with your car’s servicing and maintenance schedule to prevent mechanical issues.