What Causes Intermittent Engine Shaking?

[StJayla]

Engine intermittent shaking can be attributed to the following reasons: 1. Engine intake pipe leakage: The intake system contains numerous intake manifolds or valves. Any leakage can allow unintended gases to enter, causing the air-fuel mixture concentration in the intake manifold to become either too high or too low, ultimately leading to intermittent engine shaking or weak performance during idle. 2. Fuel system blockage or malfunction: Blockages in the fuel tank vent hole, fuel tank switch, fuel filter, or fuel lines between the tank and carburetor can prevent the engine from receiving the required fuel supply during idle. This results in a lean air-fuel mixture, weakened engine power output, and idle shaking. 3. Idle control valve failure: In fuel-injected engines, idle operation is primarily controlled by the idle control valve. The ECU adjusts the valve opening based on signals such as engine speed, temperature, and throttle position to maintain stable idle. If the valve malfunctions, it disrupts air distribution, causing uneven engine power during idle and resulting in vehicle shaking. 4. Engine carbon buildup: Carbon deposits in critical areas such as cylinders, throttle body, spark plugs, and intake valves directly impact engine power output. Excessive carbon buildup reduces ignition efficiency and intake air flow, leading to unstable engine power, idle shaking, and poor acceleration.