What Causes Loud Engine Noise and Vibration?

[DiLeah]

The causes of loud engine noise and vibration are a dirty throttle body or excessive carbon deposits on the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts. This makes starting difficult and causes uneven air-fuel mixture ratios, leading to idle vibration after a cold start. Additionally, overfilling the engine oil creates unnecessary resistance on the crankshaft, which affects power output, increases fuel consumption, and allows more oil to enter the combustion chamber. This further increases carbon deposits in the combustion chamber, adding resistance to piston movement and reducing engine power. Moreover, excessive oil increases the stirring resistance of the crankshaft and connecting rods, which also amplifies noise.