Why is the BMW's starting sound particularly loud?
2 Answers
Engine carbon buildup and substandard engine oil cause the BMW's starting sound to be particularly loud. Engine carbon buildup: As old engine oil becomes thinner with use, carbon deposits accumulate more and more. Thin engine oil is prone to burning, leading to increasing carbon buildup, which results in significant power loss. When new oil is added, the engine cannot adapt to the oil's viscosity, causing the RPM to rise, which in turn leads to louder engine noise. Substandard engine oil: Using oil that does not meet standards or adding too much oil can cause unnecessary resistance to the crankshaft's rotation, affecting power output and increasing fuel consumption. Carbon deposits in the cylinders can become red-hot, leading to premature ignition, and they also accelerate wear on the cylinders and pistons. Increased carbon buildup also negatively affects the quality of the engine oil. In short, excessive oil increases the stirring resistance of the crankshaft and connecting rods, leading to louder noise. Solutions for a particularly loud BMW starting sound: Regularly cleaning the car's intake system at a 4S shop is the most effective way to reduce carbon buildup. It is recommended to perform necessary cleaning of the intake system at around 30,000 kilometers. Regularly change the engine oil and maintain an appropriate oil level (generally slightly below the upper limit of the oil dipstick). Also, regularly clean or replace the oil filter cartridge.
As a car enthusiast who often tinkers with vehicles, I've noticed that BMWs have particularly loud startup sounds primarily due to their high-performance engine design. The high compression ratio during ignition and more aggressive fuel injection immediately trigger that roar. The exhaust system is also tuned to be louder, intentionally conveying a sense of sportiness and brand identity. BMW engineers consider these as core characteristics—for instance, the startup sound of M series models is practically an iconic growl, far more pronounced than ordinary sedans. This isn't a malfunction but a deliberate feature for rapid response and driving pleasure. However, if the startup sound becomes unusually harsh or accompanied by odd noises, it might indicate spark plug issues or an aging battery, though my own inspections on new models showed everything normal. Overall, this sound reflects BMW's tradition of pursuing thrilling driving experiences, derived from the racetrack to street cars, which is quite fascinating. Once accustomed to it in daily driving, you might even find it exhilarating—but regular maintenance is recommended to keep it in top condition.
