P0307 on BMW
Cylinder 7 Misfire Detected
P0307 on BMW vehicles indicates cylinder 7 misfire detected. Au7o has documented this code across 1 BMW model — most commonly on 7 Series. P0307 means the engine computer detected a misfire on cylinder number 7 — that cylinder isn't burning its air/fuel mixture completely or at the right moment. The PCM senses this by watching for tiny slowdowns in crankshaft speed each time cylinder 7 should fire. A misfire wastes fuel, can dump raw fuel into the exhaust, and may damage the catalytic converter over time, which is why a persistent or severe misfire often makes the check engine light flash. You may feel rough idle, shaking, hesitation, or a loss of power. Typical repair costs on BMW range from $300 to $2,400, depending on the specific model and root cause.
Common Causes of P0307
- •Worn, fouled, or incorrectly gapped spark plug on cylinder 7
- •Failed ignition coil or coil-on-plug for cylinder 7
- •Faulty, clogged, or leaking fuel injector
- •Vacuum or intake air leak affecting that cylinder
- •Low compression (worn rings, burnt/leaking valve, head gasket)
- •Damaged spark plug wire or boot (on applicable engines)
- •Carbon buildup or sticking valve
P0307 on BMW by Model
BMW 7 Series(1 issue)
- N63 Direct-Injection Fuel Injector Failure and Single-Cylinder Misfire - F01/F02 750i2009-2015
The N63's direct injectors sit in the hottest part of a hot-vee engine and fail early, either leaking down and washing the cylinder or losing flow entirely. The result is a persistent misfire isolated to one cylinder that follows the injector when you swap it to another bore - the diagnostic that separates an injector from a coil, plug, or HPFP problem. BMW went through several injector revisions and ran an index-level campaign, replacing early injectors with index 11 or higher on affected cars; checking the index number stamped on each injector is a standard step when diagnosing N63 misfires. Owners on BimmerFest report chasing a cylinder-specific misfire through coils, plugs and even swapped high-pressure fuel pumps before the injector proved to be the culprit.
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View P0307 across all makes →Frequently Asked Questions
What does P0307 mean on BMW?▼
P0307 stands for "Cylinder 7 Misfire Detected." P0307 means the engine computer detected a misfire on cylinder number 7 — that cylinder isn't burning its air/fuel mixture completely or at the right moment. The PCM senses this by watching for tiny slowdowns in crankshaft speed each time cylinder 7 should fire. A misfire wastes fuel, can dump raw fuel into the exhaust, and may damage the catalytic converter over time, which is why a persistent or severe misfire often makes the check engine light flash. You may feel rough idle, shaking, hesitation, or a loss of power. On BMW specifically, this code is documented across 1 model.
What causes P0307 on BMW vehicles?▼
Common causes on BMW: Worn, fouled, or incorrectly gapped spark plug on cylinder 7, Failed ignition coil or coil-on-plug for cylinder 7, Faulty, clogged, or leaking fuel injector, Vacuum or intake air leak affecting that cylinder, Low compression (worn rings, burnt/leaking valve, head gasket). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0307 on a BMW?▼
Repair costs on BMW range from $300 to $2,400, depending on the specific model and root cause.
Which BMW models have P0307 documented?▼
Au7o has documented P0307 on 1 BMW model: 7 Series.