AutoSense AI Knowledge Base
Engine Misfire Symptoms, Causes, and Repair Cost
A misfire happens when one or more cylinders fail to burn fuel correctly, causing shaking, power loss, and potential converter damage.
An engine misfire happens when combustion fails or happens unevenly in one or more cylinders. The result can feel like shaking, stumbling, hesitation, or a sudden loss of power.
Misfires are important to diagnose early because they can damage the catalytic converter and create unsafe driving conditions if the vehicle loses power unexpectedly.
Symptoms
- Rough idle or shaking
- Flashing check engine light
- Loss of power
- Jerking under acceleration
- Fuel smell
- Poor fuel economy
Common Causes
- Worn spark plugs
- Bad ignition coil
- Vacuum leak
- Clogged fuel injector
- Low compression
- Fuel pressure problem
- Sensor or timing issue
Severity
Moderate to high. Light misfires should be diagnosed soon. A flashing check engine light means the vehicle should be driven as little as possible.
Typical Repair Costs
$100 to $2,500+
- Ignition repairs are often the least expensive.
- Fuel injector or intake leak repairs vary widely by engine layout.
- Internal engine issues such as low compression can become major repairs.
Frequently Asked Questions
What does an engine misfire feel like?
It often feels like shaking, stumbling, hesitation, or uneven power delivery.
Can I drive with a misfire?
Short, gentle driving may be possible if symptoms are mild, but a flashing check engine light means you should stop and diagnose it quickly.
Is a misfire always spark plugs?
No. Spark plugs are common, but fuel, air, compression, and sensor issues can also cause misfires.
Related Articles
P0300 Code: Random or Multiple Cylinder Misfire
P0300 means the engine computer detected random misfires across multiple cylinders.
Rough Idle: Symptoms, Causes, and Repair Cost
A rough idle can come from air, fuel, ignition, sensor, or mechanical issues.
P0420 Code: Catalyst System Efficiency Below Threshold
A practical guide to the P0420 check engine code, catalytic converter efficiency, symptoms, causes, and repair cost ranges.
AutoSense AI
Catch Vehicle Problems Before They Become Expensive Repairs
AutoSense AI continuously monitors engine data and helps flag unusual performance patterns before rough running becomes a costly breakdown.
Join the WaitlistPricing and Waitlist
Join the AutoSense AI waitlist.
Get updates on engine health monitoring, anomaly alerts, compatibility details, and launch availability.