The Lemon IndexSmoke from the engine bay can be oil or coolant on hot parts, or the start of a fire.
Stop and get help. Pull over, turn the engine off and get everyone out. Don’t open the hood if you see flames.
Oil leaking onto the exhaust. Then: coolant leaking onto hot parts; an electrical short.
Owners describe this in 7,209 complaints to the U.S. government, most often on the Hyundai Sonata.
Cars owners report it on most
Complaints describing this symptom, by model, all years. Raw counts, not a failure rate: popular models get more complaints.
Model years that report it most
| Model year | Complaints | Share |
|---|---|---|
| 2011 Hyundai Sonata | 64 | 2% |
| 2014 Ford Escape | 53 | 3% |
| 2013 Ford Escape | 48 | 2% |
| 2015 Kia Optima | 48 | 5% |
| 2013 Kia Optima | 47 | 3% |
| 2013 Hyundai Sonata | 47 | 2% |
| 2012 Kia Optima | 45 | 4% |
| 2007 Mazda CX-7 | 44 | 8% |
| 2012 Hyundai Sonata | 43 | 3% |
| 2011 Dodge Durango | 42 | 5% |
| 2012 Jeep Grand Cherokee | 41 | 2% |
| 2018 Mazda CX-5 | 34 | 10% |
Each row is that model year's record in NHTSA complaints, not the history of any one car. Share = complaints describing this symptom out of every complaint we hold for that model year (shown when the year has 50+ complaints).
Where it makes up the biggest share
2018 Mazda CX-5 · 10% 2019 Mazda CX-5 · 9% 2007 Mazda CX-7 · 8% 2000 Dodge Stratus · 8% 2015 BMW 3 Series · 6% 2024 Chevrolet Trax · 5% 2011 Dodge Durango · 5% 2012 Dodge Charger · 5%
Model years with 150+ complaints in our data and 10+ describing this symptom, ranked by share. A high share means owners of that year who complained often mentioned it.
The details
Common causes of smoke from under the hood
- Oil leaking onto the exhaust
- Coolant leaking onto hot parts
- An electrical short
- A slipping belt or seized pulley
- Overheating
General causes, not a diagnosis. A shop should confirm the cause with tests before replacing parts.
Is it safe to drive with smoke from under the hood?
Stop and get help. Pull over, turn the engine off and get everyone out. Don’t open the hood if you see flames.
Get help right away if you notice it at all.
Of the 7,209 complaints describing it, 2% mention a crash, 14% say the car was towed, 58% mention a fire and 3% report an injury.
What the complaints show
The parts owners filed these complaints under: engine (41%), electrical system (30%), engine and engine cooling (22%), power train (8%). A complaint can list more than one.
Median odometer reading when owners reported it: 88,000 miles.
Most reports by make: Ford (1,226), Kia (715), Dodge (535), Hyundai (531), Chevrolet (471).
What owners say it cost to fix
Repair bills owners named in complaints that describe this symptom (cooling, engine, exhaust & emissions, fuel system repairs): the middle half ran $1,100 to $6,300, typical $3,200, from 88 bills.
Each figure is one repair bill as an owner wrote it in a complaint, not a quote for your car. Prices vary with the part, the shop and the year.
Related symptoms
Burning smell from car or engine Oil leak Engine overheating Car jerks when accelerating Car hesitates when accelerating Car shakes when accelerating
Quick answers
What causes smoke from under the hood?
Smoke from the engine bay can be oil or coolant on hot parts, or the start of a fire. Common causes: oil leaking onto the exhaust; coolant leaking onto hot parts; an electrical short; a slipping belt or seized pulley; overheating.
Is it safe to drive with smoke from under the hood?
Stop and get help. Pull over, turn the engine off and get everyone out. Don’t open the hood if you see flames.
Which cars have this problem most?
In complaints to NHTSA, owners describe it most on the Hyundai Sonata, Ford Escape and Kia Optima. These are raw counts, so popular models rank higher; complaints are owner reports, not proof of a defect.
How much does it cost to fix?
In 88 repair bills owners named in complaints describing it, the middle half ran $1,100 to $6,300. The right repair depends on the cause.
Counts: NHTSA owner complaints whose text describes this symptom (we matched owners' own wording, then read samples to check the matches). A complaint is an owner's report, not a diagnosis or proof of a defect. Causes and advice are general information in our own words, not repair advice for your car. Every symptom · Engine code lookup