BMW 4 Series2017

Known issues

• DPF (diesel particulate filter) blockages and forced regeneration cycles, particularly on low-mileage or urban-driven examples
• Turbocharger wastegate rattle and premature turbo failure around 80,000–120,000 miles; replacement costs €1,200–€2,000
• N47 engine timing chain tensioner failure (less common in N57 but still reported); can lead to catastrophic engine damage if ignored
• EGR valve carbon build-up causing rough idle, limp mode, and increased emissions; cleaning/replacement €600–€1,200
• Fuel injector carbon deposit issues on direct-injection engines, causing hesitation and cold-start difficulty
• Electric water pump failure leading to overheating; typically €400–€700 repair

Good for

• Fuel economy: genuine 45–50 mpg on motorway driving
• Performance: responsive diesel engines with good pulling power for a compact coupe
• Build quality: solid interior trim and robust chassis dynamics
• Practicality: reasonable boot space and comfortable 2+2 seating for short journeys