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Change Car Spark Plugs

Easy 0h45–4h00 ~75–400£
Estimated time 0h45–4h00
Estimated labour cost ~75–400£
Difficulty Easy
Vehicles
4-Series 2013-2020 14
  • 418i Petrol (B38B15A)
  • 420i, -xDrive Petrol (B48B20A)
  • 420i, -xDrive Petrol (N20B20A)
  • 420i, -xDrive Petrol (N20B20B)
  • 428i, -xDrive Petrol (N20B20A)
  • 430i, -xDrive Petrol (B48B20B)
  • 435i, -xDrive M Performance Petrol (N55B30A)
  • 435i, -xDrive Petrol (N55B30A)
  • 440i, -xDrive M Performance Petrol (B58B30A)
  • 440i, -xDrive Petrol (B58B30A)
  • M4 CS Petrol (S55B30A)
  • M4 GTS Petrol (S55B30A)
  • M4 Petrol (S55B30A)
  • M4 Petrol (S55B30A)
4-Series 2020-2025 6
  • 420i Petrol (B48B16A)
  • 420i, xDrive Petrol (B48B20A)
  • 430i, -xDrive Petrol (B48B20B)
  • M4 Competition, -xDrive Petrol (S58B30A)
  • M4 CSL Petrol (S58B30A)
  • M4 Petrol (S58B30B)

What is the role of BMW 4-Series spark plugs?

The spark plug generates a spark at the precise moment needed to ignite the air/fuel mixture in the combustion chamber of petrol (or LPG) engines. The engine management system controls ignition timing.

When should you change your BMW 4-Series spark plugs?

Manufacturers provide replacement recommendations; refer to your vehicle maintenance booklet. Generally replace every 60,000 km (45,000 km for severe use). Some vehicles with long-life plugs (titanium, platinum, iridium) can go 100,000–150,000 km.

How do I know if I need to change my BMW 4-Series spark plugs?

Via the EOBD system (mandatory since 2001 on petrol cars), faulty spark plugs will trigger fault codes, typically P0301–P0304 (misfire, cylinders 1–4). Symptoms include: difficulty starting, misfires, reduced engine power, increased fuel consumption.

Is it difficult to change BMW 4-Series spark plugs?

Difficulty level 2/5: technically easy but requires specific tools (spark plug wrench, torque wrench). Key points: wait for cold engine, clean plug well with compressed air before removal, never use a dropped plug, do not grease threads, hand-tighten then torque to specification.

2 models covered

Model Year Range Engines covered Fuel
4-Series 2013-2020 2013-2020 418d Diesel (B47D20A), 418d Diesel (N47D20C), 418i Petrol (B38B15A), 420d Diesel (B47D20A), 420d Diesel (N47D20C), 420d, -xDrive Diesel (B47D20A), 420d, -xDrive Diesel (N47D20C), 420d, -xDrive M Performance Diesel (B47D20A), 420d, -xDrive M Performance Diesel (N47D20C), 420i, -x… Diesel, Petrol
4-Series 2020-2025 2020-2025 420d mHev, -xDrive 48V (MHEV),Diesel (B47D20B+JA1), 420d mHev, -xDrive 48V (MHEV),Diesel (B47D20B+JA1), 420i Petrol (B48B16A), 420i, xDrive Petrol (B48B20A), 430d mHev, xDrive 48V (MHEV),Diesel (B57D30B+JA1), 430i, -xDrive Petrol (B48B20B), M4 Competition, -xDrive Petrol (S58B30… 48V (MHEV), Diesel, Petrol