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BMW B57 vs BMW N57: which engine is more reliable?

According to our risk index, the BMW B57 carries less risk than the BMW N57: 22/100 (low risk) versus 87/100 (very 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 BMW N57 has 3 documented serious faults, the main one being «EGR cooler leaks with risk of engine fire».

Risk index

BMW B57

22

Low risk · 3 serious faults

Lower risk

Risk index

BMW N57

87

Very 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

9 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 BMW N57 reliable?

The BMW N57 (2008-2019, successor to the M57) is a six-cylinder diesel that is mechanically robust in the basics, but it shares with the N47 and B47 the EGR cooler covered by BMW's service campaign for engine fire risk, and it inherits from the N47 the timing chain at the rear of the block, with wear cases documented mainly from 200,000 km. Without a clear history of these checks, it is worth buying with some caution.[3][4][5]

See the 4 of the BMW N57 faults

Side-by-side comparison

Comparison of BMW B57 and BMW N57
BMW B57BMW N57
Technical data
TypeEngineEngine
FuelDieselDiesel
Displacement2,993 cm³2,993 cm³
TimingChainChain
Power265–400 hp204–381 hp
Productionsince 2015[6][7]2008–2019[3][8]
Reliability
Risk index (what is it?)22Low risk87Very high risk
Documented faults44
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: EGR cooler leaks with risk of engine fire
  2. Critical severity: Rear timing chain wear
  3. High severity: Loss of thrust on twin-turbo versions due to the vacuum circuit or the actuator
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]
  • N57D30 204-211 hp, single turbo (U0/UL, 2010-2013)[2][5]
  • N57D30 245-258 hp, single turbo (O0/O1, 2008-2019)[2][5]
  • N57D30 299-313 hp twin turbo (T0/T1, 2009-2019)[2][9]
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

BMW B57

See the 8 models with the BMW B57

BMW N57

See the 10 models with the BMW N57

Other comparisons

With the BMW B57

With the BMW N57

Compare other engines

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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. BMW N57Wikipedia (inglés) · Other source · consulted 27 September 2026
  4. Motor BMW B47 - Reparación EspecializadaDasercars · Technical documentation · consulted 27 September 2026 · in Spanish
  5. 324.000 diésel de BMW tendrán que pasar por el taller en Europa, por un posible riesgo de incendio en la EGRDiariomotor · Motoring press · published 8 August 2018 · consulted 27 September 2026 · in Spanish
  6. BMW B57 (Wikipedia en)Wikipedia · Other source · consulted 4 October 2026
  7. BMW B57 (Wikipedia de)Wikipedia · Other source · consulted 4 October 2026 · in German
  8. BMW N57Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  9. Motor BMW N57: problemas, modelos y qué revisarCarexam · Motoring press · consulted 27 September 2026 · in Spanish