320i N43
Lean-burn direct-injection four. Economical when healthy and expensive when not. The injectors and NOx sensors are the whole story.
Overview
The 320i is the N43 petrol version of the BMW 3 Series coupe (E92), sold 2007–2011 with 170 PS and manual or automatic. High risk at level 4. Piezo injectors and NOx sensors both fail, both are expensive relative to the car's value, and a full set of injectors costs more than many of these cars are worth. 16 failure modes are recorded against its engine, gearbox, chassis and shared components. Prices on this page are illustrative placeholders rather than a sourced market sample. See the methodology for how the bands are derived.

BMW 3 Series coupe (E92) · photo BMW 335i Coupe (E92) Washington DC Metro Area, USA by OWS Photography · CC BY 4.0 · Wikimedia Commons
Ranked by probability × repair cost. 16 recorded in total.
Risk level −33 · Likely spend vs price −26 · all issues →
Pre-facelift or facelift, this engine spans both
The same badge either side of the changeover. Bands are split at the facelift year from the generation record.
| Phase | Years | Low | Average | High | Good buy | What differs |
|---|---|---|---|---|---|---|
| pre Pre-facelift | 2007–2009 | €3,800 | €5,300 | €7,600 | €4,550 | The specification the car launched with. |
| LCI Facelift (LCI) | 2010–2011 | €4,150 | €5,750 | €8,250 | €4,950 | N55 single-turbo replaced the N54 twin-turbo in the 335i; N57 replaced M57 in the six-cylinder diesels; Revised lights, bumpers and iDrive; Seven-speed DCT offered on the 335i |
Known issues, ranked by expected cost
Faults recorded against this engine, its components and its chassis, ranked by likelihood × repair cost. Costs are indicative ranges with a stated labour basis.
Ranked by probability × repair cost, not by how loudly a failure is discussed. Inherited from the engine, gearbox, chassis and shared components, each written once. All 16 issues in full →
Pre-purchase inspection
The same issue records, reordered into the sequence you can actually check them in: cold start, static, drive, paperwork.
1Cold startYou get one. If the engine is warm when you arrive, come back another day.
2Static checksEngine off, ideally on a lift.
3On the driveInclude low-speed manoeuvring, not just an open road.
4PaperworkOn these cars the folder is most of the value.
5OBD scanMandatory. A seller who refuses a scan has answered the question.
Mileage and servicing
What the odometer does and doesn't tell you here, plus the service items whose neglect causes the expensive failures above.
Ignore the odometer and count the injector receipts. Six injectors at €350–500 each is €2,000–3,000 on a car worth €5,000, so the only versions of this car worth buying are the ones where a previous owner has already paid that bill. Short-trip cars fare worst.
| Service item | Interval | Cost |
|---|---|---|
| Injector history The single item that determines whether this car is cheap or ruinous | check before purchase | €350–500 each |
| Spark plugs and coils Misfires get blamed on injectors when the plugs are the cause | 40,000–50,000 km | €200–350 |
| Engine oil Chain tensioner wear follows oil condition | 10,000–12,000 km | €90–140 |
What to pay
What this engine sells for, against the median of every engine in the chassis. All figures are illustrative placeholders. See the basis chips.
Enter an asking price to get a verdict against this variant's band: cheap, fair, good buy or overpriced.
United States vs Europe
1 EUR = 1.08 USD ·US figures are the EU band converted at a stated rate. No US market differential is modelled: we hold no sourced US asking prices, and inventing one would be worse than saying so. What the comparison does show for real is availability. Most of this range was never sold in the US.
- ModelBMW 3 Series 320i
- ChassisE92
- EngineN43
- Years2007–2011
- MarketCentral EU
- Windowrolling 12 months to 2026-07
Good buy isn't the same as cheapest. The good-buy figure assumes the known failure items are either done with receipts or verifiably not yet due. Full breakdown by facelift phase →
Buyer notes
Our judgement, kept separate from the records it's built on.
Everything above this line comes from the issue and specification records. This paragraph is our judgement on top of them. See how we reach it.
Full specification
Manufacturer figures for this engine and body, as recorded in the variant and engine data.
| Engine code | N43B20 |
| Configuration | I4, naturally aspirated, lean-burn · 1995 cc |
| Fuel / injection | petrol · direct |
| Model years | 2007–2011 |
| Facelift phase | Sold either side of the 2010 facelift, 2007–2009 pre, 2010–2011 LCI |
| Power / torque | 170 PS · 210 Nm |
| Transmissions | 6-speed manual · 6-speed automatic (ZF) |
| Gearbox families | Getrag six-speed manual · ZF 6HP19 / 6HP21 six-speed automatic |
| Drivetrain | RWD |
| Economy (real-world) | 7.5–9 l/100 km mixed |
| Markets | EU |