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M111 E20 MLM111 E23 ML

M111 Kompressor 2.0/2.3 (E20 ML/E23 ML) engine: faults and reliability

Mercedes-Benz M111 (1.8/2.0/2.2/2.3 and Kompressor) version

With caution

In addition to the head gasket and the adjuster oil leak common to the whole family, this version adds the wear specific to the mechanical supercharger at very high mileages: these are faults that can be checked before buying, not a reason to rule the car out.[1][2]

Years
1995–2004
Power
163–197 hp
Faults that affect it
5
0 of high or critical severity
Cars that use it
5
in our database

11 sourcesHow we work

What changes in this version

Supercharged version with a belt-driven Roots-type mechanical supercharger, available in 2.0 (E20 ML) and 2.3 (E23 ML). Around 2000 Mercedes-Benz replaced the original Eaton M62 supercharger with the smaller Eaton M45 in part of the range: the 2.0 Kompressor went from 192 to 163 hp in some markets in search of more smoothness and efficiency, while the 2.3 Kompressor stayed between 193 and 197 hp.[1][3][4][5]

Engine codes of this version: M111 E20 ML, M111 E23 ML.

Faults of the M111 E20 ML engine

The documented engine faults that affect this version and its years, from most to least important.

  1. 1Medium severityFrequency: CommonCylinder head and blockHead gasket failure with coolant lossYes: the M111 head gasket can fail with age and use, especially from around 150,000 km, causing coolant loss. At least three independent sources document this fault, in both naturally aspirated and Kompressor versions.
  2. 2Medium severityFrequency: CommonTimingCamshaft adjuster oil leak into the wiringYes: the magnet (solenoid valve) of the M111 camshaft adjuster can lose its seal, and the oil creeps up by capillary action to the connector and the wiring loom. Mercedes-Benz has the same repair cable as for the M271 (part number A2711502733), which is cheap to fit.
  3. 3Medium severityFrequency: CommonIntakeMechanical supercharger (Kompressor) wear at high mileageOn the Kompressor versions, the Eaton mechanical supercharger can wear out at very high mileages, around 250,000 km according to a specialist German guide, and need replacing with a new or reconditioned unit.
  4. 4Medium severityFrequency: OccasionalFuelFuel pressure regulator leak with petrol smellThe M111 fuel pressure regulator can leak occasionally, with a smell of petrol in the engine bay or cabin as the main sign. A German used-car guide documents it as an occasional fault, detectable with the engine running.
  5. 5Low severityFrequency: CommonInjectionMass air flow sensor failureYes: the M111 mass air flow sensor can fail with use and cause jerking or rough running. English-language Wikipedia documents it on the W210 E-Class, and a French owner survey of the SLK R170 names it as the most-cited fault on that model.

Cars fitted with the M111 E20 ML engine

Open each car to see all its faults with this engine and what to check before buying it.

Mercedes-Benz

Frequently asked questions

Is the M111 E20 ML engine reliable?

Our verdict is “With caution”. In addition to the head gasket and the adjuster oil leak common to the whole family, this version adds the wear specific to the mechanical supercharger at very high mileages: these are faults that can be checked before buying, not a reason to rule the car out.[1][2]

What faults does the M111 E20 ML engine have?

The documented ones that affect this version, by importance: head gasket failure with coolant loss (medium severity), camshaft adjuster oil leak into the wiring (medium severity), mechanical supercharger (Kompressor) wear at high mileage (medium severity), fuel pressure regulator leak with petrol smell (medium severity) and mass air flow sensor failure (low severity).

Which cars use the M111 E20 ML engine?

Mercedes-Benz Clase C W202 (1993–2000), Mercedes-Benz Clase C W203 (2000–2002), Mercedes-Benz Clase E W210 (1995–2002), Mercedes-Benz CLK C208 (1997–2002) and Mercedes-Benz SLK R170 (1996–2004).[1][4][5][6][7][8][9][10][11]

Are you buying a car with the M111 E20 ML engine?

We will put you in touch with a partner only if you authorise it in the form.

Do you have a car with this engine? Tell us which faults you have had and at how many kilometres. Report your fault.

Sources

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

  1. Mercedes-Benz M111 engineWikipedia · Other source · consulted 27 September 2026
  2. Mercedes M111: Typische Probleme und HaltbarkeitGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
  3. Mercedes-Benz M 111Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  4. Mercedes-Benz C208Wikipedia · Other source · consulted 27 September 2026
  5. Mercedes-Benz R170Wikipedia · Other source · consulted 27 September 2026
  6. Mercedes-Benz W202Wikipedia · Other source · consulted 27 September 2026
  7. Mercedes-Benz W202Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  8. Mercedes-Benz W203Wikipedia · Other source · consulted 27 September 2026
  9. Mercedes-Benz W210Wikipedia · Other source · consulted 27 September 2026
  10. Mercedes-Benz W210Wikipedia (alemán) · Other source · consulted 27 September 2026 · in German
  11. Fiabilité Mercedes SLK (1996-2004)Fiches-auto.fr · Motoring press · consulted 27 September 2026 · in French