OM656 vs 2.2 MultiJet / BlueHDi (Stellantis): which engine is more reliable?

According to our risk index, the 2.2 MultiJet / BlueHDi (Stellantis) carries less risk than the OM656: 14/100 (low risk) versus 39/100 (moderate risk). The OM656 has 2 documented serious faults, the main one being «Leak in the vacuum-driven coolant pump (fire risk)»; the 2.2 MultiJet / BlueHDi (Stellantis) has 1 documented serious fault, the main one being «Unvulcanised fuel return pipe: fuel leak and fire risk».

Risk index

OM656

Moderate risk · 2 serious faults

Risk index

2.2 MultiJet / BlueHDi (Stellantis)

Low risk · 1 serious fault

Lower risk

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

Reviewed on 30 October 202622 sources How we work

Is the OM656 reliable?

The OM656 is the roughly 3.0-litre in-line six-cylinder diesel with which Mercedes-Benz replaced the OM642 V6 from 2017 in the S-Class, E-Class, CLS, GLE, GLS and G-Class (350 d, 400 d and 450 d). It has few documented faults: the known campaign is the coolant pump one of 2021-2022, and the timing chain recall that circulates belongs to the OM654. Guides warn about the AdBlue/SCR system, the EGR and, in isolated cases, the roller rocker arms, without figures.^{[1][2][3][4][5][6][7][8]}

See the 4 of the OM656 faults

Is the 2.2 MultiJet / BlueHDi (Stellantis) reliable?

The 2.2 diesels of Stellantis's large vans (BlueHDi DW12 in the Boxer, Jumper and Movano; Multijet 3 in the Ducato) are recent engines with no fault statistics of their own. What is documented are campaigns: AdBlue and SCR software, and the fuel return pipe on 2024-2025 units, with a fire risk. Long-term history is missing.^{[9][10][11][12][13]}

See the 2 of the 2.2 MultiJet / BlueHDi (Stellantis) faults

Side-by-side comparison

Comparison of OM656 and 2.2 MultiJet / BlueHDi (Stellantis)
Item	OM656	2.2 MultiJet / BlueHDi (Stellantis)
Technical data
Type	Engine	Engine
Fuel	Diesel	Diesel
Displacement	2,925 cm³	—
Timing	Chain	Timing belt (dry)
Power	272–367 hp	120–180 hp
Production	since 2017^[1][2][14]	since 2019^{[15][16][17][18]}
Reliability
Risk index (what is it?)	39Moderate risk	14Low risk
Documented faults	4	2
Of high or critical severity	2	1
Worst severity	Critical severity	High severity
Main faults	Critical severity: Leak in the vacuum-driven coolant pump (fire risk) Medium severity: NOx sensor failure and AdBlue (SCR) system warnings Medium severity: EGR valve clogged with soot after short journeys	High severity: Unvulcanised fuel return pipe: fuel leak and fire risk Low severity: AdBlue (SCR) system: the warning light may not come on if the urea doser fails
Most expensive documented repair	No reliable data	No reliable data
Which versions to buy
BuyRecommended versions	OM656 3.0 diesel with electric assistance (D 30, from 2023)^[4][5][7]	None
With cautionVersions to be cautious about	OM656 2.9 diesel 350 d (OM 656 D 29 R SCR, from 2017)^[3][4][5] OM656 2.9 diesel 400 d (OM 656 D 29 SCR, from 2017)^[3][4][5][7]	2.2 BlueHDi 120/140/165 (DW12 RU, Euro 6d, Boxer and Jumper 2019-2023, Movano C 2021-2023)^{[5][10][19][20]} 2.2 Multijet 3 H3-Power 120/140/160/180 (Ducato, Euro 6d-Final, 2021-2023)^[9][21][22] 2.2 Multijet Euro 6e 120/140/160/180 (Ducato, Boxer, Jumper, Movano C and Proace Max, 2024 onwards)^[11][12][13]
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

OM656

See the 11 models with the OM656

2.2 MultiJet / BlueHDi (Stellantis)

Other comparisons

With the OM656

With the 2.2 MultiJet / BlueHDi (Stellantis)

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Sources

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

Mercedes-Benz OM656 engineWikipedia · Other source · consulted 9 October 2026
Mercedes-Benz OM 656Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
Rückruf für OM 656 und OM 654 Motoren wegen KühlmittelpumpeMBpassion · Motoring press · published 9 December 2021 · consulted 9 October 2026 · in German
Mercedes-Rückruf: Kühlmittelprobleme bei DieselautosAUTOHAUS · Motoring press · published 5 January 2022 · consulted 9 October 2026 · in German
DVSA – base de llamadas a revisiónDVSA (Reino Unido) · Other source · consulted 9 October 2026
Mercedes-Benz GLC (X253): Alle typischen Probleme & MängelGebrauchtwagenberater · Motoring press · consulted 9 October 2026 · in German
Mercedes OM656 Diesel: Häufige Probleme, Ursachen & Tipps zur Vermeidung von MotorschädenMBpassion · Motoring press · published 19 February 2026 · consulted 9 October 2026 · in German
Mercedes-Benz OM656 Engine Guide: Reliability, Common Problems & Tuning PotentialEuro Premium Parts · Technical documentation · consulted 9 October 2026
Fiat Ducato 2.3 Multijet 2026: Probleme, Zahnriemen, Varianten (nota sobre el 2.2 Multijet 3)PlanMyCamper · Other source · consulted 9 October 2026 · in German
Boxer: error de software del inyector de urea (alerta Safety Gate A12/01870/23)RappelConso (Gobierno de Francia) · Official body · published 25 August 2023 · consulted 9 October 2026 · in French
Ducato NG: tubo de retorno de combustible (alerta Safety Gate SR/00527/26)RappelConso (Gobierno de Francia) · Official body · published 20 February 2026 · consulted 9 October 2026 · in French
Rückruf Stellantis: Diese Transporter können Kraftstoff verlierenAuto Motor und Sport · Motoring press · published 4 March 2026 · consulted 9 October 2026 · in German
Stellantis. Risque de fuite de carburant sur les véhicules utilitairesL'Argus · Motoring press · published 12 March 2026 · consulted 9 October 2026 · in French
Mercedes-Benz S-Class (W222)Wikipedia · Other source · consulted 9 October 2026
PSA EW/DW engine (sección DW12 y DW12 RU)Wikipedia (inglés) · Other source · consulted 9 October 2026
Fiat Ducato (motores Euro 6d-Temp, 6d-Final y 6e)Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
Atención a la junta de culata del motor 2.2 de la Fiat Ducato y equivalentesAutopos · Motoring press · published 15 July 2026 · consulted 9 October 2026 · in Spanish
Opel Movano (Movano C desde 2021)Wikipedia (alemán) · Other source · consulted 9 October 2026 · in German
Jumper: error de software del inyector de urea (alerta Safety Gate A12/01876/23)RappelConso (Gobierno de Francia) · Official body · published 25 August 2023 · consulted 9 October 2026 · in French
Movano: error de software del inyector de urea (alerta Safety Gate A12/01877/23)RappelConso (Gobierno de Francia) · Official body · published 25 August 2023 · consulted 9 October 2026 · in French
ADAC Pannenstatistik 2026 (categoría Vans/Transporter)ADAC · Reliability study · published 23 April 2026 · consulted 9 October 2026 · in German
Fiat Ducato 2015-2025 Maintenance Plans (2.2 H3-Power)Haynes (Reino Unido) · Technical documentation · consulted 9 October 2026