BMW N74 (6.0–6.75)

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.