What Causes a Car to Stall While Driving Normally?

[MacIvan]

Causes of a car stalling while driving include: 1. Electrical circuit failure in the car; 2. Malfunction in the car's ignition system, starter switch, or fuses; 3. Blockage in the car's fuel system, requiring timely repair. Steps to follow when the car stalls: 1. Generally, when the car stalls, you should first press the brake, shift to N (Neutral), engage the handbrake, and then shift to P (Park). 2. Then turn off the engine and release the brake. For manual transmission cars, you also need to press the brake when stalling. The effectiveness of the car's braking depends on the condition of the brake pads. During braking, the brake pads are pressed against the brake discs or drums, creating friction to slow down or stop the car.

[Elrond]

I've experienced the car suddenly stalling while driving a few times. The most troublesome issue is with the fuel pump, especially in older cars where pump wear leads to insufficient fuel supply, causing immediate stalling when releasing the throttle. Another time, I encountered a burnt-out ignition coil – idling was fine, but pressing the accelerator caused stalling. When the mass airflow sensor gets too carbon-fouled, inaccurate signals can also lead to stalling, so I always clean that little thing during car washes. A failed crankshaft position sensor is even worse – the car won't start at all, requiring a tow truck. There's also a hidden culprit – the engine control unit; water ingress causing short circuits can leave you stranded. If stalling occurs, don't force it – pull over safely with hazard lights on immediately. Safety first.

[MacClaire]

Sudden engine stalling while driving is mostly caused by fuel or electrical system issues. I usually check the fuel pump first - if you can't hear the humming sound from the fuel tank, it's likely broken. Clogged fuel injectors can cause similar symptoms, often due to using low-quality gasoline. That's why I now exclusively fill up at Sinopec stations. If the car stalls with AC on, there's an 80% chance it's due to insufficient alternator output - the battery warning light coming on is the first sign. Ignition system failures are also common; spark plugs with heavy carbon buildup cause cylinder misfires, resulting in increased vibration and black smoke. A dirty idle air control valve can cause stalling too, especially noticeable at red lights. When repairing, always ask the mechanic to read trouble codes with a diagnostic scanner - it pinpoints the exact issue every time.

[RichardLee]

Sudden stalling depends on the specific situation. If the engine stalls when braking, check for vacuum hose leaks; if it stalls with the AC on, focus on whether the alternator belt is loose. The weirdest case I've fixed was a rat chewing through the oxygen sensor wiring, causing intermittent issues that were hard to diagnose. Poor ignition switch contact can also cause sudden power loss, which is dangerous as it may lock the steering wheel. For older cars, pay special attention to wiring degradation—engine bay heat can cause exposed wires to short-circuit and stall the engine.