Cylinder 8 Misfire Detected
The engine computer detected that cylinder 8 is misfiring, meaning it's not igniting fuel properly on one or more combustion cycles. This causes incomplete combustion, reduced power, and increased emissions from that cylinder.
What You Might Notice
- Engine hesitation or stumbling during acceleration
- Rough idle or vibration at idle
- Difficulty starting the engine
- Reduced fuel economy
- Check engine light illuminated
Most Common Causes
- 1
Faulty spark plug or ignition wire
Worn, fouled, or failed spark plugs or damaged ignition wires on cylinder 8 prevent proper spark generation, causing misfire.
- 2
Faulty ignition coil pack
A bad coil pack for cylinder 8 fails to generate sufficient voltage to fire the spark plug consistently.
- 3
Faulty fuel injector
A stuck or clogged fuel injector for cylinder 8 delivers insufficient fuel or fails to spray properly, preventing proper combustion.
- 4
Low compression or mechanical damage
Burned valves, worn piston rings, or head gasket leaks in cylinder 8 reduce compression and prevent complete fuel ignition.
How to Diagnose It
- 1
Check Faulty spark plug or ignition wire — Worn, fouled, or failed spark plugs or damaged ignition wires on cylinder 8 prevent proper spark generation, causing misfire.
- 2
Check Faulty ignition coil pack — A bad coil pack for cylinder 8 fails to generate sufficient voltage to fire the spark plug consistently.
- 3
Check Faulty fuel injector — A stuck or clogged fuel injector for cylinder 8 delivers insufficient fuel or fails to spray properly, preventing proper combustion.
- 4
Check Low compression or mechanical damage — Burned valves, worn piston rings, or head gasket leaks in cylinder 8 reduce compression and prevent complete fuel ignition.
How to Fix It
- 1
Replace spark plug and ignition wire
Remove and inspect the spark plug and ignition wire for cylinder 8; replace if worn, fouled, or damaged. Install new components rated for your vehicle.
- 2
Replace ignition coil pack
Test or replace the coil pack assigned to cylinder 8. Many vehicles use individual coil-on-plug designs; replace the coil for that specific cylinder.
- 3
Clean or replace fuel injector
Remove and test the fuel injector for cylinder 8; clean with fuel system cleaner or replace if clogged or defective.
- 4
Check compression and valve condition
Perform a compression test on cylinder 8 to check for internal engine damage. Have a mechanic inspect for burned valves or gasket leaks if compression is low.
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