Is It Normal for BMW Engines to Be Noisy?
2 Answers
It is normal for BMW engines to be noisy, as this sound is emitted by the high-pressure fuel pump. Reasons for loud engine noise: Insufficient engine oil; aging engine mounts; increased carbon deposits in the engine; aging soundproofing strips; engines equipped with high-pressure fuel pumps are those featuring direct fuel injection technology. In direct injection engines, the fuel injectors are installed inside the cylinders, requiring very high injection pressure. Therefore, direct injection engines need an additional high-pressure fuel pump. Engine oil issues: Engine oil can indeed cause variations in engine noise during operation; increased carbon deposits: carbon buildup is an unavoidable phenomenon in cars. Over time, severe carbon deposits not only reduce engine power and increase fuel consumption but also lead to louder noise.
I've driven a BMW 5 Series for five years, and I was also startled by the engine sound when I first bought it, so I specifically went to the dealership to ask. The technician said the tractor-like loud noise during cold starts is normal—that's just how BMW's inline engines are, mainly to quickly warm up the catalytic converter. It quiets down after a couple of minutes when the idle speed drops. If there's a popping sound when you floor the throttle after the engine is warm, that's the characteristic exhaust note from the sport-tuned exhaust system. However, once I heard a metallic hissing sound, which turned out to be a faulty pulley. That kind of abnormal noise is something to be wary of. I recommend having the mechanic check the sounds during every service and paying attention to any changes in the sound during daily driving.
