What Causes Engine Vibration at 1100 RPM?

[JohnMarie]

Engine vibration at 1100 RPM can be caused by the following reasons: Ignition System Issues: Check the spark plugs. If the ceramic part of the spark plug is cracked, also inspect the ignition module for proper functioning. If the spark plugs are excessively carbon-fouled, replace them. Severe Engine Carbon Buildup: The most common cause is a dirty or faulty throttle body, which can lead to idle vibration. The primary reason for a dirty throttle body is carbon buildup at the junction of the throttle valve plate shaft and the throttle body, causing imprecise throttle opening and resulting in idle vibration. Clean the fuel system and inspect the idle air control valve for carbon deposits, ensuring it is thoroughly cleaned. Unstable Fuel Pressure: If you have already cleaned the engine carbon, serviced the throttle body, replaced the gaskets and spark plugs, but still experience body vibration at idle, it is recommended to visit a 4S shop to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or incorrect readings and malfunctioning of the intake pressure sensor can both cause body vibration.