Burning Smell From Your Car? What Each Smell Means

A burning smell from a car usually points to one of five things: oil dripping on the hot exhaust, leaking coolant (a sweet smell), a slipping clutch, overheated brakes or an electrical fault. The type of smell, and when you notice it, narrows it down quickly. If you see smoke, or smell burning plastic, stop when it is safe, switch off and get everyone out.

When is a burning smell an emergency?

Stop as soon as it is safe, switch off the engine and get everyone out of the car if:

• You see smoke or flames from the bonnet, under the car or the dashboard
• You smell burning plastic or hot wiring
• A red temperature or oil warning is on at the same time
• The smell is strong and getting stronger

Stand well away from the car and from traffic. In the UAE the emergency numbers are 999 for police and 997 for the fire service (Civil Defence). Do not open the bonnet if you think there is a fire, because fresh air can feed it.

Most burning smells are not fires, but they are warnings. The sections below go through them one by one.

What does a burning oil smell mean?

A sharp, acrid smell, a bit like a hot frying pan, often with light smoke from under the bonnet when you stop. The usual cause is engine oil leaking onto the hot exhaust manifold.

• Valve cover gasket. The most common source. The gasket hardens with age and heat, and oil seeps out at the top of the engine.
• Oil filter or drain plug not tightened properly after a service.
• Oil spilled during a top-up onto the engine. This smell fades after a day or two.
• Turbocharger seals on turbo engines, sometimes with blue smoke from the exhaust.

Check the oil level with the dipstick when the engine is cold. If it is dropping between services, there is a leak or the engine is burning oil. See our engine oil leak repair, from AED 449.

What does a sweet, syrupy smell mean?

That is coolant (antifreeze). It smells sweet, a bit like maple syrup or warm sweets. It means coolant is leaking somewhere hot.

• From the engine bay: a leaking radiator, hose, water pump or thermostat housing
• Inside the cabin, often with misted windows or a damp carpet on the passenger side: a leaking heater core
• With white exhaust smoke and a falling coolant level: possibly a head gasket

Coolant is toxic, and a leak can lead to overheating, which is a serious risk in UAE summer traffic. Watch the temperature gauge and check the coolant level when the engine is cold. Never open the radiator or coolant cap on a hot engine. See engine overheating repair, from AED 399.

What does a clutch burning smell mean?

On manual cars, a slipping clutch smells like burning paper or a sharp, sulphur-like smell. It often appears after:

• Hill starts on steep ramps in multi-storey car parks
• Stop-start traffic where the clutch is held half-engaged
• Towing or carrying heavy loads

An occasional smell after a hard hill start is the clutch being worked hard. A smell that keeps returning, with the engine revving but the car not speeding up as it should, means the clutch is slipping and wearing out. See clutch replacement, from AED 899.

What does a brake burning smell mean?

Overheated brakes give off a sharp, hot, chemical smell, sometimes with smoke from one wheel. Causes include:

• Long descents with constant braking, for example coming down mountain roads such as those around Hatta. Use a lower gear and let the engine slow the car.
• A sticking brake caliper, which keeps the pad pressing on the disc. One wheel will be much hotter than the others, and the car may pull to one side.
• A handbrake left on, partly or fully.
• New pads bedding in. A light smell for the first few drives can be normal.

A brake that keeps dragging overheats the pads and discs and reduces braking. Do not touch the wheel; it can be very hot. Our brake caliper repair starts from AED 249.

What does a burning plastic or electrical smell mean?

This is the one to take most seriously. A smell of hot plastic or burning insulation can mean:

• A short circuit or overloaded wire, sometimes after an accessory was wired in
• A failing blower motor or resistor, if the smell comes from the vents
• A melting fuse or connector

Switch off, and if it continues, disconnect the battery only if you can do it safely. Do not keep driving with an electrical burning smell. Our car electrical repair service traces the circuit.

A burning plastic smell outside the car can also be a plastic bag caught on the hot exhaust. That one is harmless once removed, but check before you assume.

What about burning rubber or rotten eggs?

• Burning rubber: a slipping drive belt, or a loose hose touching a hot part. A squeal on start-up often goes with a slipping belt.
• Rotten eggs (sulphur): usually from the catalytic converter, often when the engine runs too rich or the converter is failing. It can come with a check engine light. See our exhaust smoke and emission fault repair, from AED 199.

What should I tell the workshop?

1. What the smell is like, in your own words.
2. Where it seems to come from: bonnet, a wheel, the vents or the cabin.
3. When it happens: after a long drive, in traffic, after braking, with the AC on.
4. Anything you saw: smoke colour, drips under the car, warning lights.
5. Recent work: a service, new pads, an accessory fitted.

Do you have a burning smell right now?

If there is smoke, or the smell is electrical, stop and switch off. If the car cannot be driven safely, arrange breakdown recovery; the recovery fee is agreed before the truck is sent.

Otherwise, tell us what you smell and when, and we will diagnose it and send a written quote. Diagnosis is free if you go ahead with the repair with us, otherwise it is charged at the amount on your quote. You choose OEM, aftermarket or used parts on the quote. Repairs are done at our workshop; pickup and delivery is available across Dubai, Sharjah and Ajman. Book online.