BMW 760i
Two straight-sixes on one crankshaft — that is how BMW builds a V12. The N74B60 splits the workload across two separate DME control units; each cylinder bank gets its own high-pressure pump and its own turbocharger. A failure usually affects only one side. 544 hp at 750 Nm from 1,500 rpm — the power delivery is absolutely commanding, no hesitation, no turbo lag. Under full throttle from 4,500 rpm the exhaust flap system opens and the twelve-cylinder speaks with a voice no V8 can imitate. The direct injection at up to 200 bar makes cold-start running slightly rougher than the naturally aspirated N73 predecessor. 12 spark plugs, 12 ignition coils, two turbochargers, two thermostats, electric water pump — every job costs three times as much as on a six-cylinder.
Bangle V12 with 445 hp NA — Raw and Refined
The N73 NA in the E65 was the purer V12 instrument before the turbo era. Smooth as an electric motor, but with a voice when provoked. The Bangle design still divides — the twelve-cylinder drivetrain unites all owners. Running costs are steep thanks to dual ignition coil sets and scarce parts.
Engine Weaknesses 11
The two turbochargers of the V12 are complex and expensive to replace. Oil supply issues or bearing failure result in power loss. Repair costs are very high due to the involved disassembly.
Symptoms: Power drop, whining noises, blue smoke, oil in intercooler.
Early N74B60 units used piezo injectors prone to internal leakage. A single faulty injector cannot be replaced alone — all 12 must be converted to the newer solenoid type simultaneously.
Symptoms: Rough running on individual cylinders, misfires, increased fuel consumption, smoke on cold start.
The internal membrane of the high-pressure fuel pump becomes porous, causing fuel pressure to drop. Particularly problematic on cold starts.
Symptoms: Poor cold start, hesitation at low revs, engine warning light
The V12 with TwinPower turbo and HPI direct injection carries complex electronic systems. Control units and sensors are costly to diagnose. Workshop bills are well above average.
Symptoms: Various warning lights, starting problems after long periods of standing, fault codes readable only by BMW diagnostic systems.
The coolant crossover pipe between the cylinder banks loses its seal with age. Coolant loss without visible external leakage. Repair requires removal of the intake manifold.
Symptoms: Dropping coolant level without visible leak, sweet smell in the engine bay, temperature warning during extended driving.
The wastegate actuators on both turbochargers develop play with mileage. Metallic rattling at mid-range revs is the first sign. If ignored, uncontrolled boost build-up is possible.
Symptoms: Metallic rattling or clattering at 2,000–3,500 rpm, irregular boost build-up, boost pressure regulation fault code.
Electrically driven water pump instead of a belt-driven unit. Early failures from 80,000 km documented. Failure often goes unnoticed until overheating — particularly expensive on a V12.
Symptoms: Slowly rising coolant temperature, coolant warning light, limp mode initiated by engine management.
Rear air suspension is wear-prone. Compressor and air springs age; BMW coding required on replacement — aftermarket parts cannot be fitted without a dealer diagnostic tool.
Symptoms: Car sags to one side after standing, ride-height warning on display, uneven spring rebound.
Twelve ignition coils and twelve spark plugs mean high maintenance effort. Oil ingress into the spark plug tubes through leaking cam cover gaskets accelerates failures.
Symptoms: Misfires, rough idle, power loss, engine warning light
Both cam covers tend to leak with age. Oil collects in the spark plug tunnels and destroys the ignition coils prematurely. Double the labour compared to a straight-six.
Symptoms: Oil smell in the engine bay, oil visible in spark plug tunnels on plug change, repeated ignition coil failures.
The transmission oil cooler line connections can leak with age. Transmission oil loss leads to increased wear and overheating on long motorway drives.
Symptoms: Oil drops under the car in the centre area, rising transmission temperature, transmission overheating fault code.
Vehicle Weaknesses 10
The electronic steering column lock can seize and prevent the car from starting. BMW charged around 1,800 € for repair. One of the most expensive electrical problems of this generation.
The E65 is considered an electrical nightmare: comfort access, ISOFIX, various control units, and body electronics can fail. Even minor repairs easily cost over 1,000 €.
The rear air suspension on the E65 is a frequent and expensive weak point. Air bellows and compressor typically fail from 100,000 km. The car sags at the rear, especially after standing.
Blocked panoramic roof drains let water through the C-pillar into the boot. Up to 7 control units are located there.
Hydraulic power steering pump fails. Faulty vane pump or leaking pressure hoses as causes.
A weak battery causes apparent multiple faults: Dynamic Drive, DSC, gearbox, and steering show simultaneous errors.
Plastic water pipe on top of the N62 V8 engine becomes porous and leaks. Coolant loss can lead to overheating.
Solenoid valves in the air suspension compressor scale up from condensation. Compressor can often be repaired cost-effectively.
The E65 comfort access fails frequently — from flat key batteries to faulty door handles and the CAS control unit. Diagnosis is complex and repairs accordingly expensive.
The E65's four-zone climate control frequently develops temperature regulation faults in individual zones. The water valve and IHKA climate control units are wear items that regularly fail after 10+ years.
Reports & Tests
15 owner complaints filed with NHTSA (2001–2008). Most reported: Electrical (3), Airbags (3), Suspension (3).