Mercedes-Benz C280 engine knock noise issue with no engine light present on Mercedes-Benz C280

Some Mercedes-Benz C280 owners report experiencing a knocking noise in the engine even when the engine light is not illuminated. This issue may be attributed to worn engine components, such as pistons, bearings, or connecting rods, which can develop over time. Additionally, the use of low-quality or incorrect fuel has been noted to contribute to engine knocking sounds. Carbon build-up in the combustion chamber is another potential cause, along with incorrect ignition timing and worn or faulty spark plugs. Owners experiencing this knocking noise are advised to have their vehicle inspected by a qualified mechanic to accurately diagnose and resolve the underlying issues.