What Causes Loud Engine Noise in BMW Vehicles?
1 Answers
Specific reasons include the following: 1. Engine oil issues: Engine oil can indeed cause variations in engine operating noise. In new vehicles, components within the engine cannot fully break in due to manufacturing tolerances and processes, resulting in higher internal friction. Therefore, factory-fill oil requires lower viscosity and better heat dissipation, with less emphasis on cleaning performance and oxidation resistance (rust prevention). Some factory oils even contain friction modifiers to accelerate component break-in. During the first oil change, replacing this oil with higher-viscosity formulations of different compositions will noticeably increase engine noise. 2. Carbon buildup accumulation: Carbon deposits are an unavoidable phenomenon in vehicles. Severe carbon buildup over time leads to reduced power, increased fuel consumption, and louder engine noise. During operation, impurities in gasoline form carbon deposits under high temperature and pressure. Even high-quality gasoline contains long-chain hydrocarbons that burn slowly and incompletely, inevitably forming deposits. 3. Engine mount deterioration: Worn engine mounts contribute to increased noise while introducing additional vibration and resonance issues. 4. Deteriorated sound insulation: Even with strictly standardized oil maintenance, older vehicles will subjectively sound louder primarily due to degraded overall soundproofing performance.
