330d / 335d (N57 six)
2012–2019 · diesel · 2993cc · 258hp
Engine codes: N57
Reliability, common problems and owner reviews for the Bmw 3 Series F30 330d / 335d (N57 six). Check this before you buy used.
The 330d's N57 straight-six diesel is the connoisseur's choice — wonderfully smooth, strong and far more dependable than the four-cylinder N47, with a timing chain that doesn't share the four's failure reputation. Watch the EGR cooler (known BMW diesel item), DPF on short trips, swirl flaps and high-mileage turbo/injection. Thirstier and pricier to service than the 320d, but a documented N57 is one of the most satisfying and durable diesels you can buy.
Same engine, other cars
This is the same physical engine (M57) sold under different names across brands. Reliability is broadly shared — cross-check these:
Known Issues
EGR cooler can leak/clog (known BMW diesel issue).
Fix / Workaround: Replace EGR cooler; check coolant.
Repair cost: €300–€1200
Typically appears after: 150,000 km
DPF on short trips; swirl flaps; turbo/injection at high mileage.
Fix / Workaround: Motorway regens; inspect swirl; check turbo.
Repair cost: €300–€1600
Typically appears after: 200,000 km
Mileage Thresholds
After 250,000 km: Durable six with care.
Pre-Purchase Checklist
- ☐The smooth, robust diesel six
- ☐EGR cooler + DPF history
- ☐Pricier servicing than 320d
Frequently asked questions
Is the Bmw 3 Series F30 330d / 335d (N57 six) reliable?
Maint. Sensitive — The 330d's N57 straight-six diesel is the connoisseur's choice — wonderfully smooth, strong and far more dependable than the four-cylinder N47, with a timing chain that doesn't share the four's failure reputation. Watch the EGR cooler (known BMW diesel item), DPF on short trips, swirl flaps and high-mileage turbo/injection. Thirstier and pricier to service than the 320d, but a documented N57 is one of the most satisfying and durable diesels you can buy.
What are the common problems and reviews for the Bmw 3 Series F30 330d / 335d (N57 six)?
The most commonly reported problems: EGR cooler, DPF / swirl / turbo (high miles).
Is a used Bmw 3 Series F30 330d / 335d (N57 six) worth buying?
Fine if serviced correctly — but it punishes neglect hard. History and the right consumables matter.