What is the idling, wheezing and screaming of BMW 5 Series?

The idling vibration of BMW n52 engine in Pacific Auto Network is caused by 1 and dirty throttle. Excessive carbon deposition in the throttle valve directly leads to unstable idle speed and poor acceleration of the engine. Clean the throttle. 2. Too much carbon deposition in the engine will reduce the volume of the combustion chamber, and the endothermic characteristics of carbon deposition will also lead to abnormal combustion in the combustion chamber, increase the knock probability and make the engine shake. Clean the carbon deposit inside the engine.

Causes of idling jitter of BMW n52 engine;

1, the throttle is too dirty. Excessive carbon deposition in the throttle valve directly leads to unstable idle speed and poor acceleration of the engine. Clean the throttle.

2. Too much carbon deposition in the engine will reduce the volume of the combustion chamber, and the endothermic characteristics of carbon deposition will also lead to non-growth combustion in the combustion chamber, increase the knock probability and make the engine shake. Clean the carbon deposit inside the engine.

3. The engine stalled. The spark plug is not ignited correctly or the nozzle is not atomized, and the cylinder is not completely burned or just not burned again. This jitter is more serious.

4. The fuel is not good. The poor oil quality directly affects the combustion efficiency, and the low octane number is the main reason for engine knocking. It is recommended to change to a better fuel.

5. After the hot car is started, the car does not start directly, and the oil lubrication between engine parts is not in place.

First, the reason analysis

1, the spark plug is not working well;

2. The vacuum tube leaks;

3, high-voltage line leakage;

4. The 4.PCV valve is blocked;

5. The throttle position sensor is faulty;

6, stepper motor idling fault;

7, idle speed control valve failure;

8. Abnormal throttle opening;

9. Air leakage in the air intake system.

(Photo/Text/Photo: Pacific Auto Network Q&A called Beast)