What Causes Car Jerking?
3 Answers
Car jerking during driving may be caused by the following reasons: 1. Engine or transmission malfunction: Especially for automatic transmissions, jerking frequently occurs in older vehicles during uphill driving or sudden acceleration. 2. Dirty throttle body: If the throttle body is dirty, it is recommended to clean it. 3. Abnormal throttle opening data: If abnormal, it may indicate a throttle assembly failure, and replacement is advised. 4. Excessive wear of spark plug electrode gap: Excessive gap wear leads to insufficient ignition, and ceramic part breakdown may cause spark plug misfire. If either of these spark plug conditions occurs, replacement is necessary.
I usually drive my old car to commute, and occasionally experience a jerking sensation when accelerating, which is really annoying. It's most likely an issue with the ignition system—either the spark plugs are old and misfiring, or the ignition coils are faulty, causing unstable current and intermittent engine power. Fuel supply problems could also be the culprit, like a clogged fuel filter leading to insufficient fuel delivery or dirty fuel injectors causing uneven gasoline spray. Sometimes, a dirty or sticky throttle body can also cause jerking. I think the most dangerous scenario is on the highway—if the power cuts out suddenly, it could lead to an accident. For a simple self-check, first see if there are any warning lights on the dashboard, then try replacing the spark plugs. For prevention, get a maintenance service every 20,000 kilometers to clean related components. Don't delay—jerking isn't just uncomfortable to drive with; it also wastes fuel and accelerates part wear.
Having driven for so many years, I place great importance on safety. Car jerking often stems from minor issues that can lead to major risks. Common causes include aging spark plugs leading to inconsistent ignition, or faulty ignition coils causing cylinder misfires and shaking. Fuel system problems should not be underestimated either—unstable fuel pump pressure or clogged fuel injectors can affect fuel supply stability. Transmission issues like clutch wear or obstructed oil passages may also result in jerking. Personally, I recommend pulling over immediately to inspect if jerking occurs, turning on hazard lights to alert vehicles behind. For prevention, pay attention to abnormal engine sounds during cold starts and regularly change oil and filters. Accumulation of these minor issues can damage more expensive components, so early diagnosis at a repair shop is the most worry-free and cost-effective approach.
