Also known as: n74, n74b60, n74b66, 6.6 twin-turbo v12, n74b68
BMW's twin-turbocharged V12 — in the 7 Series, and in every modern Rolls-Royce: the Phantom, Ghost, Wraith and Cullinan.
The Rolls-Royce connection is the reason this page matters. A Phantom's engine is a BMW N74, and its faults, its parts and its procedures are BMW's — which is not what a Rolls-Royce owner or an independent specialist would assume, and it makes the BMW literature directly applicable.
A twelve-cylinder engine is two six-cylinder engines sharing a crankshaft, and BMW's control system treats it that way — with two of almost everything, including two of several sensors that a fault code will identify only by bank. A misfire diagnosis on one of these is therefore twice the work and half as ambiguous as it looks.
Its recurring items are the ones every direct-injected turbo BMW has, at twice the count: coils and injectors, the valve cover and oil filter housing gaskets, and inlet-valve carbon from direct injection with no port injector.
Access is what makes it expensive rather than the parts. Almost nothing on a V12 in an engine bay designed around it is reachable without removing something else first, which is why a routine job on one is quoted like a major one.
One V12 at three displacements — 6.0 in the 760i, 6.6 in the Ghost and Wraith, and 6.75 in the Phantom and Cullinan. What separates them is displacement and calibration rather than design, which is what makes the point above about BMW literature hold across the whole Rolls-Royce range and not only the car it was written for.
Cars fitted with this engine
7 generations, across 2 makes. From the authored catalogue — an absent car means the catalogue has not reached it, not that the engine was never fitted.
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Posted about this engine
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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