The Mercedes M271 E18 engine began to be produced in 2002, it was able to immediately replace all members of the M111 family. The new generation of engines uses a completely different aluminum cylinder block with cast iron liners, as well as a two-shaft balancing mechanism.
The cylinder head is cast from the same material, with two camshafts, 4 valves per cylinder, hydraulic lifters and variable valve timing on both shafts. The M271 used two types of cylinder heads with different intake ducts, combustion chambers and camshafts: for the KE (distributed injection) and DE (direct injection) versions. The diameter of the intake valves is 30.5 mm, exhaust 27 mm. The pistons are also different between KE and DE, the connecting rods are from the M111 EVO.
An Eaton M65 compressor is used as a supercharger. The timing drive used a chain, which on the first versions of the engines stretched up to 100,000 km, later the problem was fixed. Siemens SIM4 KE/DE engine management system (for M271.942).
In 2009 the engine was reworked and the most striking difference is the replacement of the compressor with an IHI Al 0065/0066 turbocharger that blows 1.2 bar on the 204 hp model and 0.5 bar on the 156 hp cars. In addition, the cylinder head has been slightly modified, the engine management system has been changed to Siemens SIM4 LDE. Restyled engines received the prefix EVO to the name.
|Fuel system||distributed injection (M 271 E 18 ML)
direct injection CGI (M 271 DE 18 ML)
direct injection CGI (M 271 DE 18 AL)
|Power output, hp||122 – 192 (M 271 E 18 ML)
170 (M 271 DE 18 ML)
156 – 204 (M 271 DE 18 AL)
|Torque output, Nm||190 – 260 (M 271 E 18 ML)
250 (M 271 DE 18 ML)
250 – 310 (M 271 DE 18 AL)
|Cylinder block||aluminum R4|
|Block head||aluminum 16v|
|Cylinder bore, mm||82|
|Piston stroke, mm||85|
|Compression ratio||9.0 – 10.2 (M 271 E 18 ML)
10.5 (M 271 DE 18 ML)
9.3 (M 271 DE 18 AL)
|Phase regulator||on both shafts|
|Turbocharging||compressor (M 271 E 18 ML)
compressor (M 271 DE 18 ML)
IHI Al 0065/0066 (M 271 DE 18 AL)
|Recommended engine oil||5W-30|
|Engine oil capacity, liter||5.5|
|Euro standards||EURO 4/5|
|Fuel consumption, L/100 km (for C200 Kompressor W204)
|Engine lifespan, km||~320 000|
Disadvantages of the M271 E18 engine
- The most famous engine problem is the stuck exhaust valves due to soot.
- In second place is the unreliable timing chain, which can stretch up to 100,000 km.
- This is followed by frequent lubricant leaks from the oil filter housing or heat exchanger.
- The crankcase ventilation system quickly becomes dirty, so much so that the tubes burst.
- A proprietary malfunction of the EVO series engines is the ingress of fuel into the oil.