N55 — 3.0L Inline-6 Turbo
Isle & Alpine · Engine Guide
N55 — 3.0L Inline-6 Turbo
The single-turbo six that introduced TwinPower Turbo to BMW's straight-six.
Key Specifications
Displacement2,979 cc
ConfigurationInline-6 · twin-scroll turbo
Bore × Stroke84.0 × 89.6 mm
Compression10.2:1
Output300–335 hp (variant)
Torque300–332 lb-ft @ 1,200–5,000
InjectionDirect (solenoid HDE)
ValvetrainValvetronic III + Double VANOS
Fitted To
F30 335iF10 535iF07 535i GTF06/F12/F13 640iF25 X3 35iF15 X5 35iF32 435i
Oil Specification
Oil Spec
BMW Longlife-01, LL-01 FE, or LL-04 (on diesel-shared platforms).
What Makes It Special
The N55 was the first BMW turbo six to use Valvetronic, replacing the N54's twin-turbo setup with a single, more efficient twin-scroll turbocharger. Valvetronic III + Double VANOS + twin-scroll turbo is what BMW markets as TwinPower Turbo.
Its solenoid-type fuel injectors (HDE) replaced the N54's troublesome piezoelectric injectors, a meaningful reliability improvement.
Maintenance Watch Items
- Valve cover gasket — the #1 oil leak on the N55; includes the eccentric shaft seal.
- VANOS solenoids — can stick, causing rough idle and fault codes.
- Electric water pump — typical failure around 60–80k miles; replace proactively.
- Oil filter housing gasket — leaks onto the serpentine belt and causes squealing.
- Charge pipe — plastic OEM piece can crack under boost; common aluminum upgrade.
- Wastegate rattle — an annoying buzz at certain RPMs, not a failure.