What Causes Engine Idle Vibration in Cars?

[StEdward]

Engine idle vibration in cars can be caused by severe carbon deposits, aging engine mounts, ignition system failures, and other reasons. The specific causes are as follows: Severe Carbon Deposits: The main reason for severe carbon deposits in the engine is a dirty throttle body or excessive carbon buildup in the fuel injectors, which is also a common cause of engine vibration. Aging Engine Mounts: If the vibration during idle does not decrease when the car's air conditioning compressor is running, it is likely due to aging engine mounts, which need to be replaced promptly. Ignition System Failure: Ignition system failure occurs when spark plugs, high-voltage wires, or ignition coils degrade over time, leading to poor ignition performance and resulting in idle vibration.