What causes a BMW X1 to sound like a tractor?

[EmiliaLee]

BMW X1 sounds like a tractor due to: 1. Severe carbon buildup in the engine combustion chamber, causing piston slap; 2. Use of low-quality gasoline with poor anti-knock properties, leading to engine knocking; 3. Damaged valves, where the noise frequency increases with higher engine RPM; 4. Insufficient oil viscosity causing poor lubrication and resulting in timing chain friction noise; 5. Internal engine failure. Taking the BMW X1 2021 facelift sDrive20Li Fashion model as an example, its body dimensions are 4565mm in length, 1821mm in width, and 1620mm in height, with a wheelbase of 2780mm, and it features a 5-door, 5-seat SUV body structure.