What Are the Causes of Engine Stalling and Shaking at Idle?
2 Answers
The causes of engine stalling and shaking at idle are: 1. Throttle blockage, carbon buildup, or abnormal opening; 2. Carbon buildup or blockage in the fuel injectors; 3. Spark plugs being burnt or damaged; 4. Use of low-quality gasoline leading to fuel pump blockage; 5. Incomplete combustion of the air-fuel mixture in the cylinders. Solutions for engine stalling and shaking at idle: 1. Regularly clean the throttle; 2. Periodically clean the fuel injectors to prevent carbon buildup; 3. Replace the spark plugs; 4. Use gasoline from reputable gas stations. When the engine starts and runs well from low to high speeds but stalls immediately after releasing the accelerator pedal or first becomes unstable and then stalls, this phenomenon can be identified as an idle stalling fault.
I've been driving for over twenty years and have encountered situations where the car shakes violently at idle or even stalls several times. There are generally many possible causes. The most common issue is a dirty or stuck idle control valve, where carbon deposits block it from properly adjusting the engine speed, causing the RPM to fluctuate wildly when you let off the throttle. Worn-out spark plugs are another major problem, as uneven ignition leads to unstable cylinder operation, which can be fixed by replacing the spark plugs. Fuel system failures, such as clogged fuel injectors or insufficient fuel supply from the pump, can also cause uneven fuel delivery and result in shaking. Additionally, a dirty air filter or leaks in the intake piping can disrupt the air-fuel mixture ratio, making stalling more likely. I recommend starting with simple cleaning or part replacements, such as cleaning the throttle body and idle control valve—it doesn’t cost much and can restore normal operation. Regular maintenance and using high-quality engine oil can also help prevent such issues from recurring. Never ignore these problems—safety comes first.
