BMW 4 Series2021

Known issues

• Carbon buildup on direct-injection valves causing rough idle and reduced power around 40,000–80,000 miles; cleaning required every 60,000 miles
• iDrive infotainment system freezing, lag, or occasional software crashes requiring hard reset or module replacement
• Sunroof rattle and seal leakage in damp Irish conditions; drainage tubes prone to clogging
• Turbocharger wastegate rattle at cold start and low RPM, particularly on M440i models
• Electrical gremlins including intermittent dashboard warning lights, coding errors, and occasional battery drain issues
• Steering pump bearing failure causing whining noise and potential loss of power steering assist

Good for

• Smooth turbocharged petrol power delivery with good mid-range torque for everyday driving and motorway cruising
• High-quality interior, excellent infotainment when working, and premium driver comfort on long journeys
• Responsive handling and good build quality despite electrical quirks; solid platform for tuning if desired
• Decent fuel economy (25–32 mpg real-world) for a 2-litre turbo coupe if not driven hard