Cylinder 2 misfire on BMW — N20/N55/B58 ignition coil or N47 injector flow imbalance.
BMW P0302 — Cylinder 2 misfire on BMW — N20/N55/B58 ignition coil or N47 injector flow imbalance. Typical UK independent garage cost: £90–£850.
What actually causes P0302 on a BMW
BMW coil failures cluster — replace one and the next is days behind. On N47 diesel a cylinder-2 misfire is more often injector flow imbalance than electrical. Always swap a known-good coil/injector to cylinder 2 to confirm before condemning.
BMW engines that log P0302
- N20 2.0 TwinPower
- N55 3.0 single-turbo
- B58 3.0 TwinPower
- N47 2.0d
How we diagnose P0302 on a BMW
- Swap coil 2 with coil 1 — does the misfire follow?
- Read injector correction values on N47/N57 — high mg/stroke correction = injector
- Inspect plug condition — wet plug suggests injector
- Compression test if mechanical suspected
The common misdiagnosis to avoid
Spark plugs ignored — BMW recommends NGK/Bosch OE plugs at 40k on turbo petrol engines; cheap plugs cause misfires that look like coil failures.
BMW P0302 repair cost in the UK
Expect £90–£850 including parts and labour at an independent garage. Main-dealer quotes on BMW are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.
Bob's workshop tip
Never replace one BMW coil — fit a full set on petrol turbo. The next one fails within 5,000 miles and you'll do the labour twice.
Codes usually seen alongside P0302 on BMW
- P0301
- P0303
- P0304
- P0300
Symptoms drivers report with P0302
- The car feels like a 'kangaroos' when you're pulling away from traffic lights.
- A violent shudder or 'judder' specifically under heavy load, like climbing a hill in 4th gear.
- The engine light starts flashing—that's the car telling you the catalytic converter is melting.
- Lumpy idle that feels like the car is 'coughing' through the seat.
- A distinctive 'putt-putt' sound from the exhaust tailpipe when parked.
Repairs that clear P0302
- Replace plug & coil
- Injector test
For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0302 guide.