P0304 on BMW — Cylinder 4 Misfire Detected
BMW
Verified1 source
1 source
- Official data (NHTSA)official_feed
What P0304 means
Avoid long trips
A misfire is detected specifically in cylinder 4. As the fault is confined to this one cylinder, the diagnostic path targets cylinder 4's coil, plug, and injector; on BMW engines compression and injector-flow checks on cylinder 4 help separate an ignition fault from a mechanical or fuelling cause before parts are replaced.
Driveability assessment not yet available. Get a personalized AI Second Opinion for your exact car.
General information, not a diagnosis or repair instruction. Always confirm with a qualified mechanic for your specific vehicle.
Common causes
- Cylinder 4 spark plug or coil
Symptoms
- Повышенный расход топлива
- Engine misfiring
What to check first
- Swap-test coil/plug on cylinder 4
- Inspect spark well for oil
Cost data coming soonUpload your estimate to check if the price is fair