BMW M47 vs 1.7 CDTI: which engine is more reliable?

According to our risk index, the 1.7 CDTI carries less risk than the BMW M47: 36/100 (moderate risk) versus 79/100 (very high risk). The BMW M47 has 3 documented serious faults, the main one being «Intake swirl flap breakage (swirl flaps)»; the 1.7 CDTI has 3 documented serious faults, the main one being «Dual-mass flywheel and clutch wear».

Risk index

BMW M47

Very high risk · 3 serious faults

Risk index

1.7 CDTI

Moderate risk · 3 serious faults

Lower risk

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

Reviewed on 27 September 202617 sources How we work

Is the BMW M47 reliable?

The BMW M47 (1998-2007, a 4-cylinder diesel fitted to the 3 Series E46/E90, 1 Series E87, 5 Series E60, X3 E83, the Rover 75 and the Land Rover Freelander) is solid in its basic mechanicals, but the common rail versions, built since 2001, carry a serious and well-documented problem: the intake manifold swirl flaps can break and enter the cylinder, with a risk of engine damage. The turbo and injectors also account for known faults.^[1][2][3][4]

See the 6 of the BMW M47 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.^{[5][6][7][8][9][10][11]}

See the 5 of the 1.7 CDTI faults

Side-by-side comparison

Comparison of BMW M47 and 1.7 CDTI
Item	BMW M47	1.7 CDTI
Technical data
Type	Engine	Engine
Fuel	Diesel	Diesel
Displacement	1,995 cm³	1,686 cm³
Timing	Chain	Timing belt (dry)
Power	116–163 hp	100–130 hp
Production	1998–2007^{[1][2][12][13]}	2003–2015^[5][14][15]
Reliability
Risk index (what is it?)	79Very high risk	36Moderate risk
Documented faults	6	5
Of high or critical severity	3	3
Worst severity	Critical severity	Critical severity
Main faults	Critical severity: Intake swirl flap breakage (swirl flaps) High severity: Loss of power and turbo faults Medium severity: Blocked and seized injectors	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	up to €300Faulty air flow meter on the BMW M47 (loss of power)Published figure^[16]	No reliable data
Which versions to buy
BuyRecommended versions	M47D20 116-136 hp (1998-2001)^[1][3]	None
With cautionVersions to be cautious about	M47D20TU 116-150 hp (2001-2004)^[1][3][4] M47D20TU2 122-163 hp (2004-2007)^[1] M47R 116-131 hp (Rover 75, MG ZT and Land Rover Freelander, 1998-2006)^[1][17]	1.7 CDTI 100-101 hp (Z17DTH, 2003-2007)^[10][11] 1.7 CDTI 110 hp (Z17DTJ/A17DTJ/A17DTC/A17DTE, 2007-2014)^[10][11] 1.7 CDTI 125 hp (Z17DTR/A17DTR, 2006-2013)^[6][7] 1.7 CDTI 130 hp (A17DTS, 2010-2015)^[10][11]
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 M47

See the 8 models with the BMW M47

1.7 CDTI

See the 9 models with the 1.7 CDTI

Other comparisons

With the BMW M47

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.

BMW M47Wikipedia (inglés) · Other source · consulted 27 September 2026
BMW M47D20 engine specifications, problems and reliabilityBimmerPulse · Technical documentation · consulted 27 September 2026
Motor BMW M47: problemas y averíasDasercars · Technical documentation · consulted 27 September 2026 · in Spanish
BMW 3er E46: typische Probleme und SchwachstellenGebrauchtwagenberater · Technical documentation · consulted 27 September 2026 · in German
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 M47Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
BMW 3 Series (E46)Wikipedia (inglés) · Other source · consulted 27 September 2026
Opel Corsa DWikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Opel MerivaWikipedia (alemán) · Other source · consulted 27 September 2026 · in German
Caudalímetro o sensor MAF: qué es, cómo funciona y cuáles son las averías más frecuentesDiariomotor · Motoring press · consulted 30 October 2026 · in Spanish
Rover 75Wikipedia (inglés) · Other source · consulted 27 September 2026