Cam adjustersTTTOKEN0FIN
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
Haut
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
- Ralenti brutal
- 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
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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Aide à l'acheteur
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Codes d'erreur et symptômes à vérifier.
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