550i / xDrive50i 4.4 V8 Twin Turbo (N63TU)
2013–2018 · petrol · 4395cc · 450hp
Engine codes: N63B44O2, N63TU
Reliability, common problems and owner reviews for the Bmw X5 550i / xDrive50i 4.4 V8 Twin Turbo (N63TU). Check this before you buy used.
The 450 hp N63TU (F10 550i from the 2013 facelift, F15 X5 xDrive50i 2013–2018) fixed much of the first N63 — revised valvetrain, injectors and cooling — but it is still a hot-vee twin-turbo V8: valve stem seals, timing chains, hoses in the vee and oil consumption remain the expensive items as these cars age. Better than the 408 hp engine, still the costliest engine you can choose in either car.
Same engine, other cars
This is the same physical engine (N63B44O2) sold under different names across brands. Reliability is broadly shared — cross-check these:
Known Issues
Turbos sit in the 'hot vee' between the banks; the heat bakes the valve stem seals and rubber parts, giving heavy oil use and blue smoke on start-up.
Fix / Workaround: Measure consumption; stem seals are a big labour job on this V8. Shorter oil intervals than BMW's 'Longlife' help.
Repair cost: €2500–€5000
Typically appears after: 80,000 km
Timing chains and guides wear — BMW issued a timing-chain wear check (SI B11 16 14) to be done with the N63 Customer Care Package. A stretched chain throws cam-timing faults and can jump.
Fix / Workaround: Check cam timing with ISTA; replacing chains on this engine is an engine-out-level job.
Repair cost: €3000–€6000
Typically appears after: 100,000 km
Piezo injectors, coils, crankcase-ventilation lines, turbo oil and coolant lines in the vee and the low-pressure fuel sensor are recurring items (several were in BMW's Customer Care Package). Heavy battery drain is also typical.
Fix / Workaround: Ask what parts of the Customer Care Package / later campaigns were done; budget for hot-vee hoses.
Repair cost: €800–€3000
Typically appears after: 80,000 km
Mileage Thresholds
After 100,000 km: Stem seals and chain wear become the question.
Fault Codes to Scan
Pre-Purchase Checklist
- ☐Oil consumption over the last service interval
- ☐Blue smoke on cold start
- ☐Scan for cam-timing faults (chain)
- ☐xDrive transfer-case actuator and ZF 8HP service history
Frequently asked questions
Is the Bmw X5 550i / xDrive50i 4.4 V8 Twin Turbo (N63TU) reliable?
Problematic — The 450 hp N63TU (F10 550i from the 2013 facelift, F15 X5 xDrive50i 2013–2018) fixed much of the first N63 — revised valvetrain, injectors and cooling — but it is still a hot-vee twin-turbo V8: valve stem seals, timing chains, hoses in the vee and oil consumption remain the expensive items as these cars age. Better than the 408 hp engine, still the costliest engine you can choose in either car.
What are the common problems and reviews for the Bmw X5 550i / xDrive50i 4.4 V8 Twin Turbo (N63TU)?
The most commonly reported problems: Oil consumption and valve stem seals, Timing chain stretch, Injectors, coils, hoses and hot-vee leaks.
Is a used Bmw X5 550i / xDrive50i 4.4 V8 Twin Turbo (N63TU) worth buying?
Known design issues and recurring faults that were never fully resolved. Buy only with eyes open.