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BMW B57 vs 1.9 dCi: which engine is more reliable?

According to our risk index, the BMW B57 carries less risk than the 1.9 dCi: 22/100 (low risk) versus 67/100 (high risk). The BMW B57 has 3 documented serious faults, the main one being «EGR cooler leaks on the B57 (limited action on the 540d xDrive)»; the 1.9 dCi has 3 documented serious faults, the main one being «Seizure and wear of the big-end bearings».

Risk index

BMW B57

22

Low risk · 3 serious faults

Lower risk

Risk index

1.9 dCi

67

High risk · 3 serious faults

The index (0–100) weights the severity and frequency of the three most serious documented faults. How it is calculated

12 sourcesHow we work

Is the BMW B57 reliable?

The BMW B57 (2015 onwards) is the six-cylinder diesel that succeeded the N57. The sources consulted document no widespread faults: its most cited weak point is the AdBlue/SCR system, and it was left out of the big EGR campaigns that hit the N47 and N57. The timing chain is still at the back, next to the gearbox.[1][2]

See the 4 of the BMW B57 faults

Is the 1.9 dCi reliable?

The 1.9 dCi (F9Q) was Renault's first common-rail diesel (1999) and powered a large part of its range, and those of Nissan and Volvo, for more than a decade. It has well-documented weak points: on versions of up to 120 hp built before 2005, the big-end bearings can seize and the turbo tends to degrade around 150,000 km; the injectors, the EGR valve and, on the 120 hp versions, the dual-mass flywheel also fail fairly often.[3][4][5][6][7]

See the 5 of the 1.9 dCi faults

Side-by-side comparison

Comparison of BMW B57 and 1.9 dCi
BMW B571.9 dCi
Technical data
TypeEngineEngine
FuelDieselDiesel
Displacement2,993 cm³1,870 cm³
TimingChainTiming belt (dry)
Power265–400 hp80–130 hp
Productionsince 2015[8][9]1999–2011[10][11][12]
Reliability
Risk index (what is it?)22Low risk67High risk
Documented faults45
Of high or critical severity33
Worst severityHigh severityCritical severity
Main faults
  1. Medium severity: AdBlue/SCR system fault (NOx sensors, heater and pump)
  2. High severity: EGR cooler leaks on the B57 (limited action on the 540d xDrive)
  3. High severity: Timing chain wear on the gearbox side
  1. Critical severity: Seizure and wear of the big-end bearings
  2. High severity: Premature turbocharger wear
  3. High severity: Failures of the Delphi direct-injection injectors
Most expensive documented repairNo reliable dataNo reliable data
Which versions to buy
BuyRecommended versions
  • B57D30 265 hp, single turbo (B57D30O0, 2015-2020)[1]
  • B57D30 286-340 hp, twin turbo with 48 V (B57D30O2/T2, 2020 onwards)[1]
None
With cautionVersions to be cautious about
  • B57D30 320 hp, twin turbo (B57D30T0, 2015-2020)[1]
  • B57D30 400 hp, four turbos (B57D30S0, 2016-2020)[1]
  • 1.9 dCi 95-120 (F9Q, first generation, 1999-2005)[5]
  • 1.9 dCi 125-130 (F9Q, Energy dCi, 2005-2011)[5]
  • 1.9 dCi 80-101 (F9Q, vans and commercial vehicles, 1999-2007)[3][4]
AvoidVersions to avoidNoneNone

Severity of each fault: green, low; amber, medium; red, high; dark red, critical. How we rate them

Cars that each one is fitted to

Other comparisons

With the BMW B57

With the 1.9 dCi

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Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. Motor BMW B57: fiabilidad y averíasDasercars · Motoring press · consulted 4 October 2026 · in Spanish
  2. Motor BMW N57: diferencias con el B57Dasercars · Motoring press · consulted 4 October 2026 · in Spanish
  3. Renault Mégane II (2002 – 2009): Probleme & SchwachstellenGebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
  4. Renault Scénic II (2003 – 2009) – Typische Probleme & KrankheitenGebrauchtwagenberater.de · Motoring press · consulted 27 September 2026 · in German
  5. Achat d'occasion : faut-il éviter le moteur 1.9 dCi F9Q chez Renault ?Planète Renault · Motoring press · published 24 January 2024 · consulted 27 September 2026 · in French
  6. Diesels : volant moteur défectueuxFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  7. Vanne EGR : problèmes et pannesFiches-auto.fr · Motoring press · consulted 27 September 2026 · in French
  8. BMW B57 (Wikipedia en)Wikipedia · Other source · consulted 4 October 2026
  9. BMW B57 (Wikipedia de)Wikipedia · Other source · consulted 4 October 2026 · in German
  10. Renault F-Type engineWikipedia · Other source · consulted 27 September 2026
  11. Moteur F RenaultWikipédia · Other source · consulted 27 September 2026 · in French
  12. Renault Espace IVWikipedia · Other source · consulted 27 September 2026 · in German