What Causes Car Shaking at Idle Speed?

[McMakayla]

Reasons for car shaking at idle speed: 1. Severe engine carbon deposits: The gasoline sprayed by the cold start injector is largely absorbed by carbon deposits, resulting in an excessively lean mixture during cold starts and making it difficult to start. Solution: Clean the fuel system and check if the idle speed motor has carbon deposits that need cleaning; 2. Ignition system issues: Check the working condition of spark plugs, high-voltage wires, and ignition coils. Solution: Inspect if spark plugs have excessive carbon buildup and replace them if necessary; 3. Unstable fuel pressure: Check if the fuel supply pressure and intake pressure sensor are normal. Solution: Inspect fuel pressure and replace components if needed; 4. Aging engine components: Engine mounts are actually the shock absorption system of the engine, responsible for absorbing minor vibrations during operation. If engine mounts fail, these vibrations will be transmitted to the steering wheel and cabin, causing shaking at idle speed. Solution: Replace components.