M271 engine: faults and reliability

• M271 Kompressor 1.6/1.8 (KE16/KE18)

  2002–2011 · 122–194 hp · 271.910, 271.9xx, 271.942

  With caution

  It shares the weak point documented for the whole M271 family: the timing chain and the camshaft sprockets can wear prematurely, according to the specialist source consulted, which does not describe any production period free of this problem within this version.^[1]

• M271 EVO 1.8 turbo CGI (DE18 LA)

  2009–2015 · 156–204 hp · 271.8xx, DE18 LA

  With caution

  The specialist source consulted expressly notes that wear of the timing chain and sprockets persisted even in this EVO revision, despite the change from mechanical supercharger to turbo.^[1]

Buy: No known serious faults, or they have already been corrected, in this version. With caution: Worth buying if something specific is verified: history, a replaced part or a completed campaign. Avoid: High risk of a serious fault that is hard to check for or prevent.

1. 1Critical severityCommonFrequency: CommonTimingTiming chain stretch and wear of the camshaft sprocketsYes: the M271 timing chain can stretch prematurely and wear the teeth of the camshaft sprockets, with a risk of damaging the engine. A specialist source describes this weak point as persistent throughout production, including the EVO turbo revision.
2. 2Medium severityCommonFrequency: CommonTimingOil leaking from the camshaft adjuster solenoids into the wiringYes: the camshaft adjuster solenoids (magnets) of the M271 can lose their seal, and the oil wicks up to the connector and the wiring loom, and can even reach the control unit. Mercedes-Benz has a specific repair cable (reference A2711502733) that is cheap to fit.
3. 3Medium severityCommonFrequency: CommonIntakeCrankcase ventilation hose under the supercharger: it cracks and lets in false airYes: the part-load crankcase ventilation hose, located under the supercharger, dries out and cracks with heat and oil, letting in false air. It causes a rough idle, jerking and the engine warning light; the part is cheap, but labour is expensive because of the difficult access.
4. 4Low severityCommonFrequency: CommonIntakeCarbon build-up in the intake on the direct-injection EVO turbo and CGI versionsOn the direct-injection versions (EVO turbo and the short-lived 2003-2005 CGI), the M271 can build up carbon on the intake valves, a problem typical of petrol direct injection. It is treated with mechanical cleaning; good-quality petrol helps prevent it.

Severity colours: low, medium, high, critical. How we rate them

Manufacturer

Mercedes-Benz (Daimler)

Family

M271

Fuel

Petrol

Displacement

1,796 cm³

Cylinders

4

Fuel system

Turbo

Injection

Indirect injection

Timing

Chain

Power

122–204 hp

Production

2002–2015

Makes

Mercedes-Benz

Technical data^[2][3]

1. 2002–2011

   M271 Kompressor 1.6/1.8 (KE16/KE18)

   Engine with a Roots-type mechanical supercharger (Kompressor) and multipoint injection, apart from the short-lived DE18 ML direct-injection (CGI) variant from 2003 to 2005 with 170 hp, which still uses a mechanical supercharger. Capacities of 1.8 litres (since 2002) and 1.6 litres (since 2008), with outputs of 122 to 194 hp depending on the model and market. The end year of this version is approximate: the switch to the EVO turbo revision was not simultaneous across all models, and the detail for each car is in 'applications'.^[2][3]

2. 2009–2015

   M271 EVO 1.8 turbo CGI (DE18 LA)

   From September 2009, Mercedes-Benz replaced the mechanical supercharger with a turbocharger and made direct injection (CGI) standard on the 1.8-litre block, with outputs of 156 to 204 hp. It is the last evolution of the M271 before its replacement by the M270/M274 from 2011-2013 depending on the model.^[2][3]