Cam adjustersMercedes-Benz

Mercedes M274 Cam Adjusters

M274 cam adjuster and timing-control faults can sound harmless at startup but may point to expensive chain, actuator, or oil-control work.

Repair difficulty
High
Estimated cost
High if timing components and cam adjusters are replaced together.

Affected models and engines

  • Mercedes C-Class, E-Class, GLC and related petrol models using M274-family engines

Symptoms

  • Startup rattle
  • Rough idle
  • Check-engine light
  • Poor low-rpm response

Why it fails

  • Oil quality, actuator wear, chain stretch, and cam adjuster locking issues affect timing control.
  • Short cold starts can hide the noise once warm.
  • Cleared cam timing faults often return after several drive cycles.

Checks before buying

  • Start the engine completely cold.
  • Scan camshaft adaptation and timing faults.
  • Check oil service intervals.
  • Avoid cars with repeated cam timing codes and no invoice trail.

Fault codes to investigate

P0011P0014P0016

Fault codes guide diagnosis; they do not confirm a part without live data, inspection, service history, and repeat testing.

Related research

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P0011 fault code

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P0014 fault code

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Known engine and gearbox weak points.
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This is buyer guidance, not a remote mechanical inspection or a guarantee. Always verify the car in person with diagnostics and service records.