Reasons for Car Shaking When Cold but Normal When Warm
2 Answers
Severe shaking when the car is cold but normal when warm could be due to inaccurate air-fuel mixture ratio. ECU Judgment: If the car's ECU makes an incorrect judgment, it may cause errors in controlling the air-fuel mixture and ignition timing through the actuators, thereby reducing the vehicle's power output and resulting in shaking. Low Temperature: At low temperatures, the engine's internal temperature is insufficient, so more fuel should be injected during cold starts to meet power requirements. The larger the spark plug gap, the smaller the ignition energy. Poor fuel atomization at low temperatures can cause the car to shake. Coil Aging: Aging ignition coils, aging spark plug high-voltage wires, or electrical leakage can also lead to reduced ignition energy.
The reason for car engine shaking when cold but running normally when warm is most likely due to severe carbon buildup in the throttle body. During cold starts, with low engine temperature, the ECU needs to precisely control the air-fuel mixture ratio. However, carbon deposits can disrupt airflow, leading to uneven fuel injection. Additionally, aged spark plugs may cause unstable ignition at low temperatures, both contributing to the shaking. Once the engine reaches operating temperature, the carbon deposits soften, and the fuel mixture becomes more uniform, eliminating the shaking. Prolonged neglect can increase fuel consumption and potentially damage internal engine components. It's advisable to regularly clean the throttle body, inspect the spark plugs, and check the engine coolant temperature sensor—don't wait until the problem worsens. This is a common issue, especially in older vehicles or in dusty environments.
