If there is smoke or flame coming from under the bonnet, stop the car, switch it off, get everybody out, move a long way clear and ring 999. Do not open the bonnet.
That is the whole answer, and everything below is detail. If you are reading this at the roadside, do those things first.
The sequence, in order
Pull over and stop. Somewhere you can get out safely — a layby, a hard shoulder, the side of the road. Do not try to reach a garage or get home. A vehicle fire develops far faster than people expect.
Switch the engine off and, if you can do it in a second without hunting for it, take the key. Do not delay for it.
Everyone out, on the safe side. Children, passengers, the dog. Do not go back for bags, laptops, paperwork or anything else. People are hurt going back to cars.
Move well clear and upwind. A long way — a hundred metres is not an overreaction. Tyres and gas-filled struts burst, and the smoke is toxic. On a motorway or dual carriageway get behind the barrier and stand away from the direction of traffic, exactly as you would for any other stop on a fast road. Our guide to stopping on a motorway covers where to put yourself.
Call 999 and ask for the fire service. Tell them where you are, whether anyone is trapped, and whether the car is electric or hybrid. Keep other people back until they arrive.
Why the bonnet stays shut
This is the instruction people most want to disobey, because looking seems harmless and doing nothing feels wrong.
A fire in an engine bay is usually starved of air by the bonnet. Lift it and you supply that air directly, at the moment your head and hands are over the opening. Small smouldering fires become large open ones in seconds when this happens. Even releasing the catch and lifting an inch is enough.
Leave it closed. There is nothing under there you can fix at the roadside that is worth this.
Steam is a different thing
Not everything white coming from a bonnet is a fire. A boiling cooling system produces a lot of steam, and it looks alarming.
Steam is white, thin, rises and disperses, and smells slightly sweet. Smoke lingers, is grey, black or blue, and smells of burning plastic, oil or electrical insulation. A blown hose or a boiling expansion tank is an overheating problem rather than a fire, and our guide to what to do when a car overheats sets out how to handle it — including waiting for it to cool rather than opening a hot cap.
But if you are standing there uncertain which one you are looking at, treat it as smoke. The cost of being wrong in one direction is a wasted call. The cost of being wrong in the other is not.
What the smell tells you
Once everyone is safe, it is worth noticing, because it is what you will be asked.
Sweet and hot means coolant. Burnt oil, heavy and greasy, usually means a leak onto the exhaust — smoky and unpleasant, and capable of catching. Sharp, acrid, like burning plastic or an overheating plug means electrical, and that is the one that most often becomes a real fire. Petrol or diesel vapour with visible smoke means stop reading and stay well back.
These are also the smells worth acting on before anything visible happens. A burning smell with no smoke is not something to drive home on and look at tomorrow, and neither is an electrical smell with a warning light — our guide to the warning lights that mean stop now covers which ones justify pulling over immediately.
Electric and hybrid vehicles
Same first steps, with one addition: tell the operator it is electric. A high voltage battery fire behaves differently, needs different resources, burns extremely hot and can reignite long after it appears to be out. It is not something to approach with a small extinguisher, and a car that has had a battery fire or serious battery damage has to be handled and stored with that in mind afterwards. Our guide to electric vehicle recovery explains why they are moved the way they are.
Afterwards
Even a fire that was put out in a minute leaves a car that is not driveable. Wiring looms, hoses, plastics and sensors do not survive heat, and what looks like localised scorching is usually a great deal more.
Report it to your insurer, keep the fire service incident number, and photograph everything once it is safe to do so. Do not have the car taken to a scrapyard before the insurer has had a look at it — fire very often writes a vehicle off, and that decision is theirs to make.
Where it is worth calling us: once the fire service has released the scene, the car has to be moved, and it goes on a flatbed rather than being driven or rolled any distance. We recover fire-damaged and non-running vehicles across Sheffield and South Yorkshire, at any hour, to a garage, an assessor or wherever your insurer asks for it. Call DK’s Recovery on +44 7867 860723.
Frequently asked questions
Should I open the bonnet if I can see smoke?
No. Opening it feeds air to whatever is burning and can turn a smouldering fire into flames in your face. If there is any smell of burning, any acrid or plastic smoke, or any flame, leave it shut, get everyone out and call 999. The only exception is steam you are confident is coolant, and even then let it stop and cool before touching anything.
How do I tell steam from smoke?
Steam is white, it disperses quickly, it drifts upwards, and it smells faintly sweet from the coolant. Smoke is thicker, hangs about, is grey, black or blue rather than pure white, and smells of burning plastic, oil or electrics. If you are not certain which one you are looking at, treat it as smoke.
How far away should I stand from a burning car?
A long way. Fire services advise standing well back, and a hundred metres is not an overreaction. Tyres, gas struts, airbag units and pressurised components can burst violently, and the smoke from a burning vehicle is toxic. Get upwind, get behind a barrier if you are on a motorway, and keep other people back too.
What if it is an electric or hybrid car?
Same first steps, and tell the 999 operator it is electric or hybrid so the right resources are sent. Do not attempt to tackle it. A lithium battery fire burns very hot, is extremely hard to extinguish, and can reignite hours or even days later, which is why a damaged electric vehicle is handled and stored differently after the event.
Can a car catch fire after it has been switched off?
Yes. Electrical faults, a fuel or oil leak onto a hot exhaust, and battery damage can all develop after the engine stops. That is one reason not to leave a car that has been smoking parked in a garage or up against a building while you decide what to do.
Will insurance pay out for a fire?
Comprehensive cover normally includes fire, and third party fire and theft does as the name suggests. Report it, keep the fire service incident number and any police reference, and do not have the car moved to a scrapyard before your insurer has seen it. Fire damage frequently writes a car off even when the flames were put out quickly.
