Cylinder 11 Misfire Detected
What does P0311 mean?
The P0311 code means the vehicle's onboard diagnostic system has detected: Cylinder 11 Misfire Detected. This is a critical severity code.
Common Symptoms
- Engine misfire on cylinder 11
- Rough idle and vibration
- Check Engine Light flashing
- Reduced power output
- Exhaust has fuel smell
Probable Causes (Ranked by Likelihood)
- Faulty spark plug or ignition coil on cylinder 11 Very High
- Fuel injector failure on cylinder 11 High
- Low compression in cylinder 11 Moderate
- Vacuum leak near cylinder 11 intake Moderate
- Timing chain or valve train issue Low
Step-by-Step Diagnostic Procedure
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Inspect and replace spark plug on cylinder 11 -- check for fouling, damage, or incorrect gap
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Swap ignition coil from cylinder 11 with a known-good cylinder and retest
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Test fuel injector operation using a noid light and resistance measurement
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Perform a compression test on cylinder 11
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Check for vacuum leaks around cylinder 11 intake runner
Frequently Asked Questions
Can I drive with code P0311?
You can drive short distances if the light is steady. A flashing Check Engine Light means catalytic converter damage is imminent -- stop driving and have the vehicle towed.
What vehicles have a cylinder 11?
Only V12 engines have a cylinder 11. These are typically found in luxury and high-performance vehicles from Ferrari, Lamborghini, Mercedes-Benz, BMW, and Aston Martin.
Are V12 misfires expensive to fix?
The repair cost for the misfire itself (spark plug, coil, injector) is similar to other engines. However, labor costs on V12 engines are higher due to the complexity and tight packaging of the engine bay.