M550d / M50d 3.0d Tri-Turbo (N57S)
2013–2018 · diesel · 2993cc · 381hp
Engine codes: N57S
Reliability, common problems and owner reviews for the Bmw X5 M550d / M50d 3.0d Tri-Turbo (N57S). Check this before you buy used.
The 381 hp N57 straight-six diesel in the F10 M550d (2012–2016) and F15 X5 M50d (2013–2018). A far better engine than the four-cylinder N47: the chain (also at the gearbox end) rarely fails, and 300,000+ km is common. Items to budget: the EGR cooler (2018 recall), the crankshaft vibration damper, the swirl-flap actuator, DPF on short trips and injectors at high mileage. The tri-turbo N57S adds three turbos and complex plumbing — strong but expensive when a turbo or the charge-air system fails.
Same engine, other cars
This is the same physical engine (N57S) sold under different names across brands. Reliability is broadly shared — cross-check these:
Known Issues
BMW recalled a wide range of 2010–2017 four- and six-cylinder diesels in 2018 because the EGR cooler could leak coolant; glycol deposits in the EGR system could, in rare cases, ignite. Even after the recall the EGR valve and cooler clog on short-trip cars.
Fix / Workaround: Check that the EGR recall has been carried out (BMW dealer VIN check). Clean or replace a clogged EGR valve; drive regularly on the motorway.
Repair cost: €300–€1200
The N57's crankshaft pulley/vibration damper rubber separates; a wobbling pulley can throw the belt.
Fix / Workaround: Inspect for wobble and cracks; replace when the rubber has separated.
Repair cost: €300–€600
Typically appears after: 150,000 km
The intake swirl-flap actuator fails (fault codes, limp mode); DPF on short trips; injectors at high mileage. The N57's timing chain is also at the gearbox end but rarely fails.
Fix / Workaround: Replace the actuator/manifold as needed; motorway driving for the DPF.
Repair cost: €300–€1500
Typically appears after: 180,000 km
Mileage Thresholds
After 150,000 km: Damper, EGR and swirl actuator are usually due.
Pre-Purchase Checklist
- ☐EGR recall done (VIN check)
- ☐Crankshaft pulley wobble at idle
- ☐ZF 8HP oil/filter service (pan with integrated filter)
- ☐xDrive: transfer-case actuator faults or clunks
Frequently asked questions
Is the Bmw X5 M550d / M50d 3.0d Tri-Turbo (N57S) reliable?
Expensive — The 381 hp N57 straight-six diesel in the F10 M550d (2012–2016) and F15 X5 M50d (2013–2018). A far better engine than the four-cylinder N47: the chain (also at the gearbox end) rarely fails, and 300,000+ km is common. Items to budget: the EGR cooler (2018 recall), the crankshaft vibration damper, the swirl-flap actuator, DPF on short trips and injectors at high mileage. The tri-turbo N57S adds three turbos and complex plumbing — strong but expensive when a turbo or the charge-air system fails.
What are the common problems and reviews for the Bmw X5 M550d / M50d 3.0d Tri-Turbo (N57S)?
The most commonly reported problems: EGR cooler — 2018 recall, Crankshaft vibration damper, Swirl-flap actuator, DPF and injectors.
Is a used Bmw X5 M550d / M50d 3.0d Tri-Turbo (N57S) worth buying?
Won't fail catastrophically, but when things do go wrong the repairs cost a lot. Budget accordingly.