How a Parked Car Can Catch Fire: Causes, Risks, and How to Prevent It

A parked car can catch fire due to electrical faults, battery failures, fluid leaks contacting hot components, residual heat igniting nearby combustibles (like dry grass), poorly installed accessories or chargers, flammable items left inside, prior crash or flood damage, or arson/external ignition. Though uncommon, it happens often enough that automakers and regulators have, in multiple cases, advised owners to park outdoors while safety defects are addressed.

How a parked car can ignite

Most parked-vehicle fires trace back to energy still present after shutdown (12‑volt power, stored heat in exhaust parts, or battery chemistry) or to external ignition sources. Below are the main technical paths that can lead to ignition even when the engine isn’t running.

• Electrical system faults: Short circuits in wiring harnesses, corroded modules, faulty relays, or moisture-intruded connectors can overheat and spark. Anti-lock brake control units, alternator diodes, and under-hood fuse boxes have all been implicated in fires with vehicles turned off.
• Battery-related failures:
  – 12‑volt lead‑acid batteries can outgas hydrogen and ignite if a spark occurs near loose terminals or failing cables.
  – Lithium‑ion packs (EVs and some hybrids) can experience thermal runaway due to internal defects, physical damage, or contamination; risk increases during/after charging or following impact or water intrusion. Loose lithium cells (e.g., vape pens, power banks) left in hot cabins can also fail.
• Fuel and fluid leaks: Fuel, brake fluid, power-steering fluid, or transmission fluid leaking onto hot surfaces or energized components can ignite. Some defects allow fluid intrusion into electronic modules, causing shorts and fires hours after parking.
• Hot components igniting combustibles: A recently driven catalytic converter or diesel particulate filter can exceed 600°C. Parking over dry grass or mulch can start a ground fire that then engulfs the car.
• Aftermarket or poorly installed accessories: Remote starters, inverters, dash cams, subwoofers, seat heaters, and trailer wiring that are unfused, misrouted, or tapped into the wrong circuits can overheat or arc long after ignition is off.
• Charging and block heaters: Faulty EV charging equipment, damaged cords, loose outlets, and extension cords (for EV trickle charging, plug-in hybrids, or engine block heaters) can overheat and ignite nearby materials while the car sits.
• Pressurized or flammable items left inside: Aerosol cans, lighters, vape devices, spare lithium batteries, oxygen cylinders, and some solvents can vent or explode in heat, providing both fuel and ignition.
• Rodent damage: Chewed insulation and exposed conductors can short, especially in engine bays and under-dash areas where nesting occurs.
• External ignition sources: Arson, garage fires, wildfires/embers, lightning strikes, or nearby equipment fires can ignite a parked vehicle from the outside in.

Any one of these factors can be sufficient under the right conditions. The risk is generally low day to day but rises with known defects, recent damage or flooding, improper wiring, or extreme heat conditions.

Notable real-world recalls and cases

Recent safety actions underscore that parked-vehicle fires are a recognized risk and are treated seriously by automakers and regulators.

• Hyundai and Kia (2023): Roughly 3.3 million vehicles were recalled in the U.S. for a potential brake control module defect that could cause electrical shorts and fires. Owners were advised to park outside and away from structures until repairs were completed.
• Chevrolet Bolt EV (2020–2023): Batteries from specific production ranges were recalled for potential internal defects that could lead to fires, often when parked and charging. Guidance included software limits, avoiding parking indoors or near structures, and battery replacements.
• Engine block heater/charging cord recalls (multiple brands, 2019–2024): Several truck and car makers recalled block heater cables or charging cords prone to overheating while parked, with recommendations to stop use or park outdoors until remedy.
• ABS/PCV heater and under-hood module recalls (various brands, 2017–2024): Multiple campaigns targeted moisture intrusion or electrical heater faults that could lead to fires even with the ignition off.

These examples show that defects in energized components, charging gear, or fluid-intruded modules can ignite a vehicle at rest, prompting “park outside” advisories until repairs are made.

Warning signs your parked car may be at risk

Some issues telegraph trouble before a fire starts. Pay attention to these clues, especially after service, accessory installation, a collision, or heavy rain/flooding.

• Burning, melting, or electrical “hot” smell after shutdown, or smoke from wheel wells or the engine bay.
• Unusual ticking or crackling from under the hood or underbody shortly after parking (beyond normal cooling noises).
• Repeated blown fuses, weak or rapidly draining 12‑volt battery, or accessories that intermittently cut out.
• Warning lights tied to ABS, battery/charging, or stability control systems; or brake fluid level drops without visible leaks.
• Visible fluid seepage on or near electrical modules, or dampness inside fuse boxes/connectors.
• Rodent droppings, nesting material, chewed insulation, or nut shells in the engine bay or cabin filter area.
• Swollen, hot-to-the-touch, or hissing portable batteries (vape devices, power banks) stored in the cabin.

Act promptly if you notice these signs: park outside, disconnect added accessories, and schedule inspection—especially if a recall applies to your vehicle.

Prevention checklist

A few practical steps can meaningfully reduce the already-low odds of a parked-vehicle fire, and they take on extra importance in hot weather or after service work.

1. Check for recalls: Use your VIN with your national safety agency’s recall tool (e.g., NHTSA in the U.S.) and subscribe to automaker notifications.
2. Install accessories correctly: Use proper fuses, wire gauges, and grounding. Avoid “add-a-fuse” spaghetti. If unsure, have a professional do the work.
3. Manage chargers and cords: Unplug cheap or damaged USB chargers/inverters when parked. For EVs/PHEVs, use UL/CE-listed EVSEs on dedicated circuits; avoid extension cords and worn outlets.
4. Don’t park on dry grass or mulch after driving: Hot exhaust components can ignite ground cover within minutes.
5. Store flammables safely: Keep aerosols, lighters, vape devices, spare lithium cells, and oxygen bottles out of hot cabins and away from sunlight.
6. Maintain the electrical system: Secure battery terminals, replace frayed cables, and address parasitic drains. Fix fluid leaks promptly.
7. After a crash or flooding: Have EV batteries, high-voltage cabling, and 12‑volt systems professionally inspected; hidden damage can surface days later.
8. Rodent deterrence: Seal food sources in the garage, use deterrents, and consider rodent-resistant loom tape or engine-bay inspections during peak seasons.
9. Garage safety: Install smoke alarms, keep combustibles away from the vehicle, and ensure adequate ventilation if charging indoors.
10. Follow automaker guidance: If told to park outside due to a defect or software update, do so until the remedy is complete.

Prevention hinges on eliminating ignition sources, controlling fuel paths, and managing heat—especially in and around energized components.

What to do if a parked car is smoking or on fire

Rapid, safe action protects people first and can limit property damage. Here’s how to respond.

• Call emergency services immediately and give your exact location; don’t delay to troubleshoot.
• Keep your distance and stay upwind. Warn others away. If indoors, evacuate the structure.
• Do not open the hood or doors—introducing oxygen can cause a flashover.
• If trained and it’s a very small incipient fire, use a dry chemical (ABC) or CO2 extinguisher from a safe position.
• For EVs/hybrids, assume high-voltage risk. Inform responders of the vehicle type; battery incidents may reignite and often require large volumes of water.
• If feasible and safe, move nearby vehicles or combustibles away to prevent spread.
• After extinguishment, do not attempt to re-power or charge the vehicle; have it towed for inspection.

Personal safety is paramount. Even small vehicle fires can escalate quickly; leave full suppression to professionals whenever there’s any doubt.

FAQs and persistent myths

Some widely shared claims mix truth and misconception. Here’s what evidence and safety guidance suggest.

• Sunlight through a water bottle can start a car fire: It’s plausible for focused light to scorch or melt interior trim under rare conditions, but full ignition is unlikely. Avoid leaving clear bottles on seats or the dashboard in direct sun.
• Hand sanitizer spontaneously ignites in hot cars: Alcohol-based gels are flammable but typically need an ignition source (spark, flame). Store tightly closed, out of direct sunlight, and away from heat or smoking materials.
• EVs catch fire more often than gasoline cars: Available datasets suggest EV fire rates per vehicle or vehicle-mile are not higher and may be lower than for internal-combustion vehicles, though comparisons vary by methodology. EV battery fires are rarer but can be more intense and harder to extinguish.
• Turning the engine off eliminates risk: Many modules remain powered, and components stay hot for some time. Defects, fluid leaks, or damaged wiring can still ignite after shutdown.

Understanding the limits of each claim helps focus on practical precautions rather than myths.

Summary

A parked car can catch fire due to residual heat, electrical faults, battery failures, fluid leaks, improper accessories or charging, flammable items in the cabin, or external ignition. While the probability is low, real-world recalls and incidents show the risk is credible. Reduce it by keeping up with recalls, installing and using electrical gear correctly, avoiding dry vegetation when parking, storing flammables safely, and acting fast if you notice warning signs. If advised to “park outside,” follow that guidance until repairs are complete.

What would make a car set on fire?

Cars catch fire due to a combination of flammable fluids (like fuel or oil), an ignition source (such as a spark from a damaged electrical system or a hot exhaust), and the presence of oxygen. Major causes include faulty fuel and electrical systems, engine or exhaust overheating, and mechanical or manufacturing defects, often accelerated by a lack of proper vehicle maintenance or by accidents that damage critical components. 
Common Causes of Car Fires

• Fuel System Issues: Leaks from damaged or poorly routed fuel tanks, lines, or injectors can release flammable gasoline, which can ignite from a spark or hot surface. 
• Electrical System Failures: Exposed or damaged wiring from wear, accidents, or even rodent damage can short-circuit and create sparks, igniting fuel or other nearby materials. 
• Overheating: An engine can overheat from a lack of coolant, an engine oil leak, or a failing water pump. The exhaust system, especially the catalytic converter, can also become extremely hot and ignite flammable debris or fluids that come into contact with it. 
• Mechanical Failures: Issues with components like a faulty battery, worn hoses, or other mechanical defects can lead to leaks or sparks that start a fire. 
• Defects and Debris:
  • Design/Manufacturing Defects: Faults in a vehicle’s design or manufacturing process can create inherent risks for fire, such as faulty ground bolts or wiring issues, as seen in some recalled vehicles. 
  • Flammable Debris: Accumulation of oily rags, spilled fluids, or dry vegetation under the vehicle can increase the risk of fire if they come into contact with a heat source. 
• Accidents: Crashes can rupture fuel lines and tanks, damage electrical systems, or damage engine components, leading to leaks and sparks that can quickly ignite. 
• Poor Maintenance: A lack of regular vehicle maintenance is a frequent human-caused factor, as it contributes to the development of leaks, worn wiring, and other mechanical issues that can lead to fires. 

This video explains the common causes of car fires: 1mBig QuestionsYouTube · Mar 8, 2025
Preventing Car Fires

• Perform Regular Maintenance: Follow your vehicle’s recommended maintenance schedule to address issues like fluid leaks, wiring problems, and engine overheating early. 
• Check for Leaks: Be vigilant for puddles of oil, coolant, or fuel under your car, especially after an oil change. 
• Inspect Wiring: Periodically check under the hood and dashboard for any signs of cracked or damaged wiring. 
• Address Warning Lights: Pay attention to dashboard warning lights, especially those related to temperature or fuel. 
• Be Aware of Odors: Promptly investigate unusual smells, such as burning rubber or metal, which could indicate a developing fire hazard. 
• Report Recalls: Respond to manufacturer recalls for potential design or manufacturing defects that could lead to a fire. 

How do cars catch on fire while parked?

Cars catch fire when parked due to fuel leaks, electrical issues, or engine overheating, where leaks can contact hot surfaces like the exhaust or catalytic converter, and damaged wiring can cause short circuits or ignite flammable materials. Other causes include faulty components, damage from rodents, improper aftermarket installations, and sometimes even external factors like refracted sunlight. A collision is not necessary, as a significant number of fires result from mechanical or electrical failures that occur independently. 
This video explains the common causes of car fires and how they spread: 1mRatchets And WrenchesYouTube · Aug 11, 2019
Fuel Leaks

• Ignition of flammable liquids: A leaking fuel line, faulty connection, or damaged fuel tank can drip gasoline or diesel fuel. 
• Contact with hot parts: If this leaked fuel or the resulting vapors come into contact with a hot engine component, exhaust manifold, or catalytic converter, it can ignite. 

Electrical Issues

• Short circuits: Opens in new tabWater entering electrical modules or short circuits from damaged wiring can cause components to overheat, leading to a fire. 
• Faulty batteries: Opens in new tabA malfunctioning battery can generate excess heat or sparks, creating an ignition source. 
• Poor wiring: Opens in new tabDamaged or poorly routed wiring from wear, damage, or improper installation of aftermarket parts can also pose a fire risk. 

Engine Overheating 

• Failed cooling systems: Opens in new tabA lack of coolant or a failing water pump or cooling fan can prevent the engine from cooling properly. 
• Oil leaks: Opens in new tabA leaking oil pan can lead to oil collecting on the engine and igniting when the engine overheats. 
• Hot exhaust components: Opens in new tabAn overheated engine can cause gaskets and seals to fail, leading to oil leaks onto a hot exhaust manifold. 

This video shows how an engine oil leak can lead to overheating and potential fire: 56sCNA InsiderYouTube · May 10, 2021
Other Causes

• Hot catalytic converters: Clogged or overworked catalytic converters can become extremely hot, potentially igniting nearby flammable debris like dry leaves. 
• Rodent damage: Animals can chew on wires or build nests that act as tinder, increasing the risk of electrical shorts or direct ignition. 
• Aftermarket accessories: Improperly installed lights, alarms, or other aftermarket devices can introduce electrical faults and cause fires. 
• External heat sources: In rare cases, refracted sunlight from a reflective object like a mirror or water bottle can focus intense heat on upholstery, potentially starting a fire. 

Why would a car suddenly burst into flames?

Fluid (especially fuel) leaks, electrical problems, crudely installed and/or low quality aftermarket accessories, design flaws, and driving over combustible materials like dried leaves or grass are the most common reasons. In some cases, an overheating engine or exhaust system could be a fire hazard too.

What part of a car is most likely to catch fire?

1: Fuel System Leaks. Leaks in the fuel system are the most common cause of vehicle fires, so that’s why they take the top spot on our list. A fuel system leak is really dangerous.