What Causes Severe Idle Vibration in the Mondeo 1.5T?

[McEllie]

The reasons for idle vibration in the Mondeo include severe engine carbon buildup, ignition system issues, and unstable oil pressure. Below are detailed explanations: Severe Engine Carbon Buildup: The most common cause of car vibration is a dirty throttle body or excessive carbon buildup in the fuel injectors. Additionally, higher temperatures require more fuel for cold starts, and carbon buildup can significantly affect the smoothness of cold starts. Solution: Clean the fuel system and check if the idle control valve has carbon buildup; it should be thoroughly cleaned. Ignition System Issues: Inspect the condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or weak spark plug firing can also lead to such issues. Solution: Check if the spark plugs have excessive carbon buildup and replace them if necessary. Unstable Oil Pressure: If you've already cleaned the engine carbon buildup, throttle body, replaced gaskets and spark plugs, but still experience idle vibration, it's recommended to visit a 4S shop to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or incorrect readings from the intake pressure sensor can cause body vibration. Solution: Check the oil pressure and replace components if necessary.