Why does the car shake and stall at idle speed?
2 Answers
Car shaking and stalling at idle speed is caused by a dirty throttle body or excessive carbon deposits in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start fuel injector will be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making it difficult to start the engine. In this situation, the car will only start easily once the carbon deposits have absorbed enough gasoline to reach saturation. An engine is a machine that converts other forms of energy into mechanical energy. It was invented in the UK and can refer to either a power generation device or the entire machine including the power unit (such as gasoline engines, aircraft engines). Types of engines include internal combustion engines (e.g., gasoline engines), external combustion engines (e.g., Stirling engines, steam engines), and electric motors.
I remember once when I was waiting at a red light, my car suddenly started shaking violently and almost stalled, which scared me so much that I immediately pulled over. Later, after inspection, it turned out that the throttle was too dirty, with excessive carbon buildup affecting the air intake, leading to unstable idling. Another common issue is the ignition system, such as worn-out spark plugs or faulty ignition coils, causing rough starts. Problems like clogged fuel lines or incorrect fuel injection from the injectors can also have an impact. Some cars experience this due to aging engine mounts, which reduce vibration damping, allowing the vibrations to be directly transmitted. If you encounter this situation, don’t panic—first check the air filter and throttle. If the shaking occurs right after maintenance, it might just be the computer adjusting to new data, and it should resolve itself in a couple of days. If the problem persists, it’s best to visit a repair shop early and have them read the fault codes with a diagnostic tool.
