What are the reasons for the loud engine noise in Mercedes-Benz GLC?

[MacCollin]

Mercedes-Benz GLC engine noise may be caused by the following reasons: 1. Incorrect engine oil condition: When the viscosity of the engine oil is too high, it can easily lead to operational issues in the engine, reducing lubrication effectiveness and causing friction during operation, which results in noise. 2. Insufficient belt tension: When the engine belt tension is insufficient, the engine will produce sharp noises during operation, significantly affecting the driver's experience. 3. Leakage in the intake or exhaust pipes: When there is a leakage in the intake or exhaust pipes, starting the engine will cause gas to escape from the leakage points during intake and exhaust, leading to vibrations and noise.