What Causes Severe Idling Car Vibration?
2 Answers
Severe idling car vibration can be caused by: 1. Engine intake pipe leakage: The intake system contains many intake manifolds or valves. Leakage allows unintended gases to enter, resulting in excessively high or low concentrations of the air-fuel mixture in the intake manifold; 2. Fuel system blockage or malfunction: Blockage of the fuel tank cap vent, fuel tank switch, fuel filter, or fuel lines between the tank and carburetor can lead to a lean mixture and weakened engine power output. Idling refers to the operation of the engine under no load, where it only needs to overcome the internal friction resistance of its components without delivering external power. A well-functioning engine typically idles between 550 to 800 revolutions per minute.
I often encounter the problem of severe shaking when the car is idling. After summarizing, there are several common causes. Worn spark plugs or damaged ignition coils lead to uneven ignition, causing the engine cylinders to work out of sync and resulting in severe vibration; a dirty or stuck throttle valve restricts airflow, disrupting the air-fuel ratio; aging or cracked rubber parts in the engine mounts fail to dampen vibrations, which are then directly transmitted to the car body; issues in the fuel system, such as clogged fuel injectors or a dirty fuel filter, cause unstable fuel supply and exacerbate the shaking. Ignoring these issues may accelerate engine wear, drastically increase fuel consumption, or even lead to breakdowns while driving. Regularly inspecting these small components—such as replacing spark plugs every 30,000 kilometers or cleaning the throttle valve—can prevent many problems, ensuring stable engine operation and saving both hassle and money.
