BMW B47 vs BMW M47: which engine is more reliable?

According to our risk index, the BMW B47 carries less risk than the BMW M47: 73/100 (high risk) versus 79/100 (very high risk). The BMW B47 has 3 documented serious faults, the main one being «EGR cooler leaks with risk of engine fire»; the BMW M47 has 3 documented serious faults, the main one being «Intake swirl flap breakage (swirl flaps)».

Risk index

BMW B47

High risk · 3 serious faults

Lower risk

Risk index

BMW M47

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

Reviewed on 27 September 202611 sources How we work

Is the BMW B47 reliable?

The BMW B47 (since 2014, successor to the N47) improves the timing chain tensioner, guides and oil supply and greatly reduces the failure rate of its predecessor, but it is not free of problems: the EGR cooler has been the subject of several BMW technical campaigns for engine fire risk since 2018, and the turbo and particulate filter need careful maintenance.^[1][2][3][4]

See the 4 of the BMW B47 faults

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.^[5][6][7][8]

See the 5 of the BMW M47 faults

Side-by-side comparison

Comparison of BMW B47 and BMW M47
Item	BMW B47	BMW M47
Technical data
Type	Engine	Engine
Fuel	Diesel	Diesel
Displacement	1,995 cm³	1,995 cm³
Timing	Chain	Chain
Power	114–228 hp	116–163 hp
Production	since 2014^[1]	1998–2007^{[5][6][9][10]}
Reliability
Risk index (what is it?)	73High risk	79Very high risk
Documented faults	4	5
Of high or critical severity	3	3
Worst severity	Critical severity	Critical severity
Main faults	Critical severity: EGR cooler leaks with risk of engine fire High severity: Timing chain wear (improved, but is it really at the front?) High severity: Premature turbo wear from neglected maintenance	Critical severity: Intake swirl flap breakage (swirl flaps) High severity: Loss of power and turbo faults Medium severity: Blocked and seized injectors
Most expensive documented repair	up to €2,000Premature turbo wear from neglected maintenancePublished figure^[3]	No reliable data
Which versions to buy
BuyRecommended versions	None	M47D20 116-136 hp (1998-2001)^[5][7]
With cautionVersions to be cautious about	B47 114-150 hp, single turbo (2014-)^[2][4] B47 168-190 hp, single turbo (2014-)^[2][4] B47 202-228 hp, twin-turbo (2015-)^[2][4] B47C20 (MINI Cooper D/SD and Countryman, 2014-)^[1][4]	M47D20TU 116-150 hp (2001-2004)^[5][7][8] M47D20TU2 122-163 hp (2004-2007)^[5] M47R 116-131 hp (Rover 75, MG ZT and Land Rover Freelander, 1998-2006)^[5][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 B47

See the 19 models with the BMW B47

BMW M47

See the 7 models with the BMW M47

Other comparisons

With the BMW B47

With the BMW M47

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Sources

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

BMW B47Wikipedia (inglés) · Other source · consulted 26 September 2026
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 26 September 2026 · in Spanish
Motor BMW B47: problemas, modelos y qué revisarCarexam · Motoring press · consulted 26 September 2026 · in Spanish
Motor BMW B47 - Reparación EspecializadaDasercars · Technical documentation · consulted 26 September 2026 · in Spanish
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
BMW M47Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
BMW 3 Series (E46)Wikipedia (inglés) · Other source · consulted 27 September 2026
Rover 75Wikipedia (inglés) · Other source · consulted 27 September 2026