What are the causes of idle vibration in a BMW 320 engine?
1 Answers
The causes of idle vibration in a BMW 320 engine are as follows: Dirty throttle body or excessive carbon buildup in the fuel injectors: When there is excessive carbon buildup inside the engine, the gasoline sprayed by the cold start injector will be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making it difficult to start the engine. In this situation, the engine will only start easily once the carbon deposits have absorbed enough gasoline to become saturated. After starting, the gasoline adsorbed on the carbon deposits will be drawn into the combustion chamber by the engine's vacuum suction force, causing the air-fuel mixture to become too rich. This fluctuation between lean and rich mixtures leads to idle vibration after a cold start. The lower the temperature, the more fuel is required for a cold start, and the presence of carbon deposits will significantly affect whether the cold start proceeds smoothly. Unstable fuel pressure: If you have already cleaned the engine carbon deposits, cleaned the throttle body, replaced the gaskets and spark plugs, but still notice body vibration at idle, it is recommended to visit a 4S shop to check whether the fuel supply pressure and intake pressure sensor are functioning normally. Abnormal fuel pump supply pressure or incorrect readings and poor performance of the intake pressure sensor can both cause body vibration.
