Piezo injector failure (lean-burn petrol)
Attaches to piezo-injectors at component level · Fuel · carried by 22 variants across 8 chassis
Overview
Piezo injector failure (lean-burn petrol) is a common fault recorded against piezo-injectors at component level, typically from 80–160k km. It shows up as rough idle, shaking at standstill, misfire warnings, poor cold running, sometimes limp mode. Where it's documented, the repair runs €350–€500 (per injector fitted and coded; six per engine, costs dated 2026-07), and it can be partly checked before you buy. 22 variants across 8 chassis in this database inherit it.
What happens
Symptom. Rough idle, shaking at standstill, misfire warnings, poor cold running, sometimes limp mode.
Cause. The stratified-charge petrol engines use piezo injectors that are sensitive to fuel quality and wear out. They typically fail one at a time over several years.
Sources. BMW injector revision programme; goodwill coverage in several EU markets
How to check it
OBD scan
Scan for per-cylinder misfires and check how many injectors have already been replaced. A car with all six done recently is worth a real premium over one with none.
Mandatory. A seller who refuses a scan has answered the question.
Every variant that carries this
| Variant | Chassis | Body | Years | Risk | Good buy | Cost as % of good buy |
|---|---|---|---|---|---|---|
| 320i N43 | E90 | sedan | 2007–2011 | R4 | €3,950 | 11% |
| 320i N43 | E91 | wagon | 2007–2011 | R4 | €4,200 | 10% |
| 320i N43 | E92 | coupe | 2007–2011 | R4 | €4,550 | 9% |
| 320i N43 | E93 | convertible | 2007–2011 | R4 | €4,450 | 10% |
| 325i N53 | E90 | sedan | 2007–2011 | R4 | €5,250 | 8% |
| 325i N53 | E91 | wagon | 2007–2012 | R4 | €5,550 | 8% |
| 325i N53 | E92 | coupe | 2007–2013 | R4 | €6,050 | 7% |
| 325i N53 | E93 | convertible | 2007–2013 | R4 | €5,900 | 7% |
| 330i N53 | E90 | sedan | 2007–2011 | R4 | €6,000 | 7% |
| 330i N53 | E91 | wagon | 2007–2011 | R4 | €6,350 | 7% |
| 330i N53 | E92 | coupe | 2007–2011 | R4 | €6,900 | 6% |
| 330i N53 | E93 | convertible | 2007–2011 | R4 | €6,750 | 6% |
| 116i N43B16 | E87 | hatchback | 2007–2011 | R3 | €3,500 | 12% |
| 116i N43B16 | E81 | hatchback | 2007–2011 | R3 | €3,100 | 14% |
| 118i N43 | E87 | hatchback | 2007–2011 | R3 | €3,900 | 11% |
| 118i N43 | E81 | hatchback | 2007–2011 | R3 | €3,450 | 12% |
| 118i N43 | E82 | coupe | 2007–2011 | R3 | €4,000 | 11% |
| 118i N43 | E88 | convertible | 2008–2011 | R3 | €4,200 | 10% |
| 120i N43 | E87 | hatchback | 2007–2011 | R3 | €4,250 | 10% |
| 120i N43 | E81 | hatchback | 2007–2011 | R3 | €3,800 | 11% |
| 120i N43 | E82 | coupe | 2007–2011 | R3 | €4,400 | 10% |
| 120i N43 | E88 | convertible | 2008–2011 | R3 | €4,650 | 9% |
The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.