Why Your Car Smells Bad (And How to Actually Fix It)

You notice it the moment you open the door. Or worse, your passenger notices it before you do.

Cars pick up smells from all over the place and hold onto them. Most advice jumps straight to "buy an air freshener", but a freshener on top of a smell doesn't fix it. You just end up with two smells instead of one. The fix is working out what's causing it first.

Car smell decoder: Everyday smells you can fix yourself

Musty or damp

The most common one, and the most overlooked. Moisture gets into carpet and mats from wet shoes, a spilled drink, a leaking seal or rain blowing in. If it doesn't dry out properly, mould and mildew start to grow, and they produce that musty smell no freshener can beat.¹

• Find the water first. Lift the floor mats and press on the carpet underneath. If it's damp, that's your source.
• Dry it properly. Doors open on a sunny day, a dehumidifier, or wet vacuum extraction.
• Then clean. An enzyme-based fabric cleaner breaks down what's left behind.
• Musty only when the AC runs? That points to the cabin air filter or the AC system itself. See the next section.

Stale or stuffy

That flat, closed-in smell a car gets when it sits for a while, or does lots of short trips on recirculated air. A tired cabin air filter is often part of it, because it holds onto dust and moisture and pushes air through them every time the fan runs.

• Replace the cabin air filter. On most cars it sits behind the glovebox, and your owner's manual will show you where. Any mechanic can swap it quickly if you'd rather not.
• Air it out properly. Windows down, fresh air setting rather than recirculate, and take it for a decent drive.
• Vacuum the lot. Built-up dust and grime add to that stale smell.

Food and takeaway

Drive-throughs, road trips and kids in the back. Food smells start on the surface, but crumbs and spills left in a warm car break down fast, and an Australian summer speeds that up.

• Vacuum thoroughly, including seat crevices, under the seats and around the console.
• Treat spills. An enzyme cleaner on the stain, then extract it with a wet vacuum.
• Skip the freshener until it's clean. Otherwise you'll get fries and fragrance at the same time.

Sweat and body odour

Fabric seats soak up sweat slowly, especially from gym gear, work uniforms and hot days with the windows up. It builds so gradually that the driver is usually the last to notice.

• Enzyme clean the seats and carpet.
• Air the car out after the gym or a hot day, rather than leaving it sealed up.
• Don't forget leather. It wipes clean easily, but the stitching and foam underneath can still hold odour.

Smoke

The hardest of the lot. Smoke settles into fabric, the headliner, plastics and the ventilation system, so airing the car out barely touches it. It needs a proper process, which we've covered step by step in our guide to removing smoke smell.

Smells that mean see a mechanic

Don't cover any of these with a freshener. They can point to a mechanical problem, and some are genuine safety issues.

• Petrol or fuel. A faint smell right after filling up that clears quickly is usually normal. A fuel smell that hangs around or gets stronger can mean a leak, and fuel leaks are a fire risk.
• Exhaust fumes in the cabin. Exhaust contains carbon monoxide, which you can't see and can be dangerous to breathe. Get it checked straight away.
• Sweet, like syrup. Often a sign of a coolant leak, sometimes from the heater system inside the cabin.
• Rotten eggs. Commonly linked to the catalytic converter, part of the exhaust system.
• Burning. Burning rubber, oil, plastic or an electrical smell can come from belts, brakes, the clutch, an oil leak or wiring. None of them should be ignored.

Once the cause is fixed

With the source dealt with, two things keep the cabin smelling good.

• Reset the soft surfaces. Our Handover Spray is made for carpet and fabric and helps neutralise odour-causing molecules. Give carpet, mats and fabric a light mist and let it dry. Treat it like cologne: keep it off plastics, leather, Alcantara and suede, and wipe any overspray off trim with a damp cloth.
• Keep it fresh. An Overtake gel in the front centre cup holder or near a vent runs around four weeks in most cars. At that point you're maintaining a clean car, not covering up a problem.

Common questions

Why does my car smell musty when I turn on the AC?
Usually the cabin air filter or moisture sitting in the air conditioning system. Replace the filter first. If the smell stays, have the AC system checked.

Why does my car smell like petrol?
A faint smell right after refuelling is normal and should clear quickly. If it lingers or gets stronger, have a mechanic check for a fuel leak as soon as possible.

Why does my car smell worse in hot weather?
Heat speeds up everything that causes smells: damp carpet, food residue, sweat in the upholstery and smoke in the fabric. A smell you barely notice in winter can become obvious in a hot car.

What's the fastest way to get rid of a bad smell in my car?
Remove any rubbish, open the windows and run the fan on fresh air for a few minutes. That buys you time. The lasting fix is finding the source and cleaning it out.

Related reading: how to make your car smell good and why air fresheners give you a headache.