OBD-II Code
P0311
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$180–$4,200
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
P0311 is a cylinder 11 misfire — this code only exists on V12 platforms (BMW N73/N74/M73, Mercedes M275/M279, Aston Martin AM11/AM29, Ferrari F140, Rolls-Royce N74), where cylinders 7-12 are the right bank.
How a shop works this
The ECU has already told you which cylinder. That makes the fastest honest test a swap: move one part to another cylinder and see whether the fault moves with it. It identifies the fault instead of guessing at it, and it costs nothing.
Photograph the coils before you touch anything, and note which is which.
Cylinder numbering is not the same across manufacturers, and V6 and V8 bank layouts differ by maker — look up the firing order and bank layout for your engine before you move parts, or you can spend an hour swapping coils on the wrong bank.
Move the cylinder 11 ignition coil to a cylinder that is not misfiring, put that cylinder's coil on 11, clear the code, and run it until the misfire returns.
On a modern coil-on-plug engine the coil is the most common single answer to a cylinder-specific misfire, which is why it is the first thing to move — not because it is the cheapest part. A misfire that is there even at idle is the classic dead-coil pattern.
- The misfire follows the coil to its new cylinderThe coil is the fault. Replace it. If the engine has real mileage on it, the other coils are on the same clock.
- The misfire stays on cylinder 11The coil is fine. Look at the coil connector and the harness around it next — chafed and rodent-damaged connections at that plug are a common second answer — then pull the plug.
Read the plug you pulled, and check the boot for carbon tracking.
Black and sooty means it has been running rich. White or blistered means lean or too hot. Oil-wet points at valve seals or rings. Fuel-wet points at an injector holding open. A carbon-tracked boot arcs to the head and imitates a dead coil for the price of a new boot. On an older engine with a distributor, the cap, rotor and plug wires belong in this step too.
If spark is accounted for, go to fuelling, then to compression.
An injector balance or flow test comes first because it is quicker. Compression test second: a cylinder more than about 15% below its neighbours is mechanical, and no ignition part will fix it. A vacuum leak on this one runner sits alongside these — a leak big enough to affect every cylinder would be setting P0300 instead.
A flashing check-engine light means the misfire is putting raw fuel into the catalytic converter, which can destroy it quickly. Stop driving as soon as it is safe to. A steady light with a mild misfire is less urgent, but stop anyway if it shakes hard, loses power, overheats, or makes a noise it was not making before.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Likely causes
- Failed ignition coil (cylinder 11)Most common
- Damaged coil connector or harness at cylinder 11
- Worn spark plug or carbon-tracked boot (cylinder 11)
- Clogged or leaking fuel injector (cylinder 11)
- Low compression on cylinder 11
- Vacuum leak at the cylinder 11 intake runner
Read the full diagnostic procedureP0311 is a cylinder 11 misfire — this code only exists on V12 platforms (BMW N73/N74/M73, Mercedes M275/M279, Aston Martin AM11/AM29, Ferrari F140, R…
P0311 is a cylinder 11 misfire — this code only exists on V12 platforms (BMW N73/N74/M73, Mercedes M275/M279, Aston Martin AM11/AM29, Ferrari F140, Rolls-Royce N74), where cylinders 7-12 are the right bank.
Diagnostic ladder is the same conceptually as on a V8 but mechanically harder
- each bank has its own DME on most modern V12s, its own coil per cylinder, its own VANOS/CVVT actuator, and on direct-injected V12s like the N74, its own high-pressure fuel pump.
- Start by pulling the cylinder 11 coil and plug — inspect for fouling, swap coil with a known-good cylinder on the same bank, and re-run.
- If the misfire follows the coil, replace it (BMW N74 coils run $80-120 each; Ferrari F140 coils run $200-280).
- Check fuel pressure on bank 2 (high-pressure pump is bank-specific on N74); a failing HPFP starves the right bank under load and shows up first on cylinder 11 because of its position in the fuel rail.
- Caveat: on V12s the rear cylinders are nearly unreachable without partial intake removal — quote labor honestly because a 4-hour V12 misfire diagnosis is realistic.
Vehicle-specific patternsBMW N73 V12 (760i E65/E66, 2003-2008) — index-12 injector failure on cylinder 11 is the signature; the original-spec injectors were recalled and upda…
BMW N73 V12 (760i E65/E66, 2003-2008) — index-12 injector failure on cylinder 11 is the signature; the original-spec injectors were recalled and updated to index-12. Use ISTA to read injector adaptation values; anything more than 0.4ms correction is failing. BMW N74 V12 (760Li F02, Rolls-Royce Ghost/Wraith, 2009-2019) — rod bearing wear pattern shows on cylinder 11/12 before catastrophic failure; oil analysis catching copper at 60K miles is the early warning. Mercedes M275 V12 biturbo (S600, CL600, SL600, 2003-2014) — turbo oil-feed line failure starves the right bank turbo bearing, causing oil ingestion into cylinder 11 intake.
- 2006-2012Ferrari 599 GTB F140 V12 — coil and HT lead degradation on cylinder 11; access requires intake plenum removal.
Estimated repair$180 to $4,200.
Look up another code
P0311 — frequently asked
What does a P0311 code mean?
See deep dive below for full diagnostic context.
What causes a P0311 code?
Common causes: Failed ignition coil (cylinder 11); Damaged coil connector or harness at cylinder 11; Worn spark plug or carbon-tracked boot (cylinder 11); Clogged or leaking fuel injector (cylinder 11); Low compression on cylinder 11; Vacuum leak at the cylinder 11 intake runner.
What are the symptoms of a P0311 code?
Typical symptoms: Check engine light.
Is it safe to drive with a P0311 code?
Depends on the light. Flashing: stop as soon as it is safe to — raw fuel is reaching the catalytic converter. Steady, and it only feels rough: a short drive to a shop is usually fine. Either way, stop if it shakes hard, loses power, overheats or makes a new noise. Estimated repair: $50-$2,000.
How do I diagnose a P0311 code?
The ECU has already told you which cylinder. That makes the fastest honest test a swap: move one part to another cylinder and see whether the fault moves with it. It identifies the fault instead of guessing at it, and it costs nothing. 1. Photograph the coils before you touch anything, and note which is which. 2. Move the cylinder 11 ignition coil to a cylinder that is not misfiring, put that cylinder's coil on 11, clear the code, and run it until the misfire returns. 3. Read the plug you pulled, and check the boot for carbon tracking. 4. If spark is accounted for, go to fuelling, then to compression.
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