BMW B57 vs 1.7 CDTI: which engine is more reliable?

According to our risk index, the BMW B57 carries less risk than the 1.7 CDTI: 22/100 (low risk) versus 36/100 (moderate 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 1.7 CDTI has 3 documented serious faults, the main one being «Dual-mass flywheel and clutch wear».

Risk index

BMW B57

Low risk · 3 serious faults

Lower risk

Risk index

1.7 CDTI

Moderate risk · 3 serious faults

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

Reviewed on 4 October 202613 sources How 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 1.7 CDTI reliable?

The 1.7 CDTI (Isuzu, 2003-2015) is a simple, widely used diesel, but it has built up accounts of soot-fouled EGR valves and injectors, a clogged diesel particulate filter (DPF) with oil dilution, wear of the dual-mass flywheel and clutch, and of the Hitachi-brand alternator; it also requires the timing belt to be changed every 150,000 km or 6 years to avoid a serious failure.^{[3][4][5][6][7][8][9]}

See the 5 of the 1.7 CDTI faults

Side-by-side comparison

Comparison of BMW B57 and 1.7 CDTI
Item	BMW B57	1.7 CDTI
Technical data
Type	Engine	Engine
Fuel	Diesel	Diesel
Displacement	2,993 cm³	1,686 cm³
Timing	Chain	Timing belt (dry)
Power	265–400 hp	100–130 hp
Production	since 2015^[10][11]	2003–2015^[3][12][13]
Reliability
Risk index (what is it?)	22Low risk	36Moderate risk
Documented faults	4	5
Of high or critical severity	3	3
Worst severity	High severity	Critical severity
Main faults	Medium severity: AdBlue/SCR system fault (NOx sensors, heater and pump) High severity: EGR cooler leaks on the B57 (limited action on the 540d xDrive) High severity: Timing chain wear on the gearbox side	High severity: Dual-mass flywheel and clutch wear High severity: Clogged diesel particulate filter (DPF) and oil dilution Critical severity: Timing belt: risk of serious failure if not changed on time
Most expensive documented repair	No reliable data	No 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]	1.7 CDTI 100-101 hp (Z17DTH, 2003-2007)^[8][9] 1.7 CDTI 110 hp (Z17DTJ/A17DTJ/A17DTC/A17DTE, 2007-2014)^[8][9] 1.7 CDTI 125 hp (Z17DTR/A17DTR, 2006-2013)^[4][5] 1.7 CDTI 130 hp (A17DTS, 2010-2015)^[8][9]
AvoidVersions to avoid	None	None

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

1.7 CDTI

See the 7 models with the 1.7 CDTI

Other comparisons

With the BMW B57

With the 1.7 CDTI

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Sources

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

Motor BMW B57: fiabilidad y averíasDasercars · Motoring press · consulted 4 October 2026 · in Spanish
Motor BMW N57: diferencias con el B57Dasercars · Motoring press · consulted 4 October 2026 · in Spanish
Circle L engineWikipedia (inglés) · Other source · consulted 27 September 2026
Essai complet Opel Astra (H) : fiabilité et avisFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
Essai complet Opel Zafira 2 : fiabilité et avisFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
Essai complet Opel Meriva : fiabilité et avisFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
Opel Astra H (A04): Probleme & KaufberatungGebrauchtwagenberater.de · Other source · consulted 27 September 2026 · in German
Opel Meriva A: ProblemeGebrauchtwagenberater.de · Other source · consulted 27 September 2026 · in German
Opel Meriva B: ProblemeGebrauchtwagenberater.de · Other source · consulted 27 September 2026 · in German
BMW B57 (Wikipedia en)Wikipedia · Other source · consulted 4 October 2026
BMW B57 (Wikipedia de)Wikipedia · Other source · consulted 4 October 2026 · in German
Opel Corsa DWikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Opel MerivaWikipedia (alemán) · Other source · consulted 27 September 2026 · in German