2017 BMW 4 Series 430i B48B20O0 (F32 (Coupe), F33 (Convertible), F36 (Gran Coupe))

Engine identity

Oils and fluids

Service and parts data

Common and chronic problems

• High-pressure fuel pump wear
• Timing chain tensioner noise in early B48 engines
• Carbon buildup on intake valves (direct injection engines)

First checks

• Oil and filter change history to avoid sludge buildup
• Coolant level and condition
• Turbocharger boost response and leaks
• Inspection of timing chain noise or rattle
• Brake fluid condition

Before replacing parts

• Save fault codes and freeze-frame data before clearing anything.
• Check engine oil, coolant and transmission fluid using the correct temperature and service procedure.
• Verify power, ground, connectors, hoses, leaks and live data before replacing expensive parts.

Important notes

• The B48 engine replaced the earlier N20 turbo inline-4 from 2014 onwards.
• Available globally, configurations and emissions differ slightly by market.
• Gran Coupe is a 4-door sedan variant; engine and technical specs largely similar.