BMW 320d (E90/E91 2007–2012)
N47 diesel – common issues, typical fault codes and how this platform behaves when problems start.
At a Glance
- Engine: 2.0L N47 common‑rail turbo diesel.
- Years covered: approximately 2007–2012 E90/E91 320d.
- Known for: timing chain concerns, EGR/DPF issues, swirl flap and boost leaks.
Common Issues on This Platform
- Timing chain wear and noise from the rear of the engine.
- EGR valve sticking or cooler problems leading to EGR flow codes.
- DPF blockage or pressure sensor issues on cars doing short trips.
- Boost leaks and vacuum control problems affecting turbo response.
- Glow plug and glow control unit failures causing hard starting.
Typical OBD2 Codes on This Car
These link to general explanations. Over time you can add more BMW‑specific deep dives like the 320d EGR guide.
- P0401 – EGR Flow Insufficient (generic)
- P0401 on BMW 320d – platform-specific guide
- P0420 – Catalyst/DPF Efficiency Below Threshold
- P2453 – DPF Differential Pressure Sensor A Circuit Range/Performance
- P0300 – Random/Multiple Cylinder Misfire
How to Approach Diagnostics
- Confirm service history – oil changes, EGR/DPF work and any timing chain attention.
- Scan all modules (engine, DPF/particulate, glow plug control) and save the full code list.
- Use live data to watch EGR duty, DPF pressure, boost and fuel rail pressure under load.
- Plan EGR/DPF cleaning or replacement only after confirming sensors and wiring are sound.