BMW Buyer's Guide

Comprehensive Used Car Analysis
← Back to E65 / E66
N73B60 6.0L V12 Petrol
N73B60 6.0L V12 Petrol
1 / 2

N73B60

6.0L V12 Petrol
N-series • N73 family • 2003–2008
25%
Engine Reliability
The N73 is BMW's most complex and least reliable engine. It was the first BMW with direct injection, using finicky piezo injectors. The combination of V12 complexity, dual ECUs, and early direct injection technology creates a maintenance nightmare. Any repair is extraordinarily expensive. Only for the bravest (or wealthiest) enthusiasts.
6.0L
Displacement
V12
Layout
445 hp
Power
600 Nm
Torque
Petrol
Fuel
Naturally aspirated
Aspiration
Technology & Features
Direct injection (first BMW DI engine)Dual ECUValvetronicPiezo injectorsIndividual coil-on-plug (12)
Fuel SystemDirect injection (piezo)
ValvetrainDOHC 48-valve, Valvetronic
Used In 1 Application
7 Series E65 / E66 760i, 760Li
1
Known Issues
1
Critical
1
Wear Items
1
Applications

Known Issues – N73B60

critical Extreme Complexity & Reliability Issues Common (>40%)
The N73 direct-injection V12 is extremely complex with dual ECUs, individual coil-on-plug for 12 cylinders, and piezo injectors. Any repair is extraordinarily expensive.
Typical Mileage
60,000–120,000 km
Est. Repair Cost
€2,000–€10,000+
DIY Friendly
✗ Specialist
MisfiresLimp modeMassive repair bills

Wear & Maintenance – N73B60

Spark Plugs (24 total) Every 40,000 km
NewReplace
Replacement Cost€300–€600
Wear Factor65%

Applications (1)

7 Series E65 / E66

E65
2001–2008
Variants760i, 760Li
Power445 hp
Torque600 Nm
BodySedan
Reliability45%
Car-Specific Issues (E65)
criticalElectronic Nightmares
mediumSoft-Close Door Mechanism Failure

Transmissions (1)

6-Speed Automatic (ZF 6HP)
6-Speed Automatic (ZF 6HP)
1 / 2

6-Speed Automatic (ZF 6HP)

ZF • 6-speed automatic • 2003–2014

The ZF 6-speed is an excellent torque-converter automatic used across BMW, Audi, Jaguar, and others. Smooth, responsive, and very reliable when serviced properly. The 6HP26 handles up to 600Nm. Mechatronic (valve body) issues can occur at high mileage if fluid has never been changed.
Known Issues2
high Mechatronic Unit Failure Moderate (~20%)
The mechatronic unit (integrated valve body and TCU) can fail, causing erratic shifting, limp mode, or complete transmission failure. Usually caused by degraded fluid.
Typical Mileage
120,000–200,000 km
Est. Repair Cost
€800–€2,500
DIY Friendly
✗ Specialist
Harsh shiftingLimp mode (stuck in gear)Warning lightNo drive
medium Torque Converter Shudder Moderate (~20%)
Torque converter lockup clutch develops a shudder at light throttle / highway cruising.
Typical Mileage
100,000–180,000 km
Est. Repair Cost
€1,000–€2,000
DIY Friendly
✗ Specialist
Vibration at 60-100 km/hShudder under light load
Wear Items
Transmission Fluid & Filter Every 60,000–80,000 km
NewReplace
Replacement Cost€250–€500
Wear Factor50%
Transmission Pan Gasket With fluid service
NewReplace
Replacement Cost€30–€60
Wear Factor40%
Fluid TypeZF Lifeguard 6
Service IntervalEvery 60,000–80,000 km (BMW claims lifetime)