Why is the car shaking?

[MacValerie]

The reason for car shaking is severe engine carbon deposits. After driving a certain mileage, the throttle may not close properly or the idle motor may get stuck due to excessive dirt, causing high engine idle speed. The carbon deposits generated during this process lead to vehicle shaking, so carbon deposits should be cleaned promptly. Ignition system issues: When starting a cold engine, a richer air-fuel mixture is required, which demands higher ignition energy. If the spark plug gap is too large, or the ignition coil and high-voltage coil are aged, it can result in decreased ignition energy, causing the car body to shake. The spark plugs and distributor wires should be inspected, and adjustments or replacements should be made if necessary.