What Causes Idle Shaking in Automatic Transmission Vehicles?

[MicahLee]

Manual transmission vehicles may experience slight shaking during startup as the clutch is in a semi-engaged state. Below is relevant information about car idling: 1. The function of car idling: Idling is an operational state of a vehicle where the engine runs in neutral gear. The engine speed during idling is called idle speed, which can be adjusted by modifying the throttle opening. Idling essentially means the engine is "producing power without doing work." When the accelerator pedal is fully released while the engine is running, the engine enters idle state. 2. Causes of unstable idling: Direct causes include dirty, worn, or incorrectly installed mechanical components that lead to variations in cylinder power output, resulting in imbalance among cylinders and consequently unstable idling. Indirect causes refer to abnormalities in the engine's electronic control system that cause poor combustion of the air-fuel mixture, making it difficult to balance cylinder power output and leading to unstable idling.