What Causes Engine Stalling and Shaking at Idle?

[Jenkins]

The reasons for engine stalling and shaking at idle are: 1. Throttle valve clogging, carbon buildup, or abnormal opening; 2. Fuel injector carbon buildup or clogging; 3. Spark plug burning or damage; 4. Use of low-quality gasoline leading to fuel pump blockage; 5. Incomplete combustion of air-fuel mixture in the cylinder. When the engine starts and runs well from low to high speeds but stalls immediately after releasing the accelerator pedal or becomes unstable before stalling, this can be identified as an idle stalling fault. Solutions for vehicle idle shaking and stalling include: 1. Regularly clean the throttle valve; 2. Periodically clean fuel injectors to prevent carbon buildup; 3. Replace spark plugs; 4. Use gasoline from authorized gas stations.

[DelSilas]

I previously encountered an issue where my car would shake and stall at idle. At first, I thought it was a minor problem, but later discovered it was caused by worn-out spark plugs. Over time, spark plugs accumulate carbon deposits, and the electrode gap widens, leading to unstable ignition. This causes the engine to surge and shake at idle, and in severe cases, it can stall completely. I also suspected a faulty ignition coil, which supplies power to the spark plugs. If the voltage is unstable, the spark can become intermittent. Additionally, a clogged air filter can restrict airflow, disrupting the air-fuel mixture and making the engine struggle. The best solution is to first replace the spark plugs and then check the ignition coil and air filter. If left untreated, the shaking could worsen during your next drive, and you might even experience sudden loss of power at high speeds, which is extremely dangerous. I recommend replacing spark plugs every 20,000 kilometers as part of regular maintenance—don’t skimp on this small expense.

[Jane]

The reason for engine stalling and shaking at idle, as an experienced driver, I can tell you it's most likely a fuel system issue. Last time my car had the same problem, shaking like an earthquake and stalling as soon as I released the throttle. After checking, it turned out the fuel pump pressure was too low, unable to deliver fuel to the injectors, causing insufficient fuel supply at idle and making the engine gasp for air. Another possibility is clogged fuel injectors, leading to uneven fuel spray and resulting in either too lean or too rich air-fuel mixture. If the idle control valve fails or the throttle body gets too dirty, it can also cause unstable airflow. In my case, I replaced the fuel injectors and cleaned the throttle body myself, and the problem was immediately resolved. Safety first—don't wait when this happens; pull over immediately and check.

[BriannaRose]

Idle shaking and stalling may involve multiple systems. Damaged ignition components such as spark plugs or coils can cause weak or intermittent sparks; obstructed fuel supply, such as heavily carbon-fouled fuel injectors; air intake leaks can lead to an imbalanced air-fuel mixture; excessive carbon buildup in the engine may also disrupt normal combustion. When encountering this issue, check these points first.

[McReed]

The vehicle shakes and stalls at idle, which I believe is a common fault point. From my experience, the idle control system is most prone to issues. For example, unstable RPM starts the shaking, leading to stalling. This could be due to a computer control fault or a clogged idle valve that can't regulate air flow. Poor fuel quality also affects it, as impurities can cause uneven fuel injection. Additionally, aging engine mounts transmit excessive vibration into the cabin. Don't rush to repair; first, check the oil level with the dipstick yourself, as low oil can cause significant wear. If this persists, it may lead to loss of control while driving, so promptly consult a mechanic to read the fault codes with a diagnostic tool.