What Causes the Jerking Sensation During Car Acceleration?
2 Answers
Possible causes of jerking sensation during acceleration are as follows: Sludge in the transmission: Acceleration jerking and shuddering are often related to issues in the engine's fuel system, ignition, or intake systems. One possible cause is sludge buildup in the transmission fluid, which can circulate and clog the oil passages in the valve body, leading to jerking. Over time, this can result in transmission overheating, impact, slippage, and a series of other transmission problems. Engine fuel system: Next is the engine fuel system. The importance of engine oil is well-known—it provides sufficient lubrication, reduces resonance, and enhances engine smoothness. Prolonged oil deficiency can cause mild symptoms like insufficient power and increased fuel consumption, or severe consequences such as piston knocking and mechanical damage to related components. Additionally, fuel pump failure or clogged fuel filters can also reduce engine power. Intake system: Besides fuel, the engine also requires air. If components like the air filter or throttle body are clogged or malfunctioning, leading to insufficient air intake, the car may experience weak acceleration, slow speed increase, and jerking. The ignition system should not be overlooked either—if spark plugs misfire, leak, or fail to atomize properly, it can also affect engine acceleration.
I've been driving for over a decade, and acceleration hesitation is most commonly caused by aging spark plugs or faulty ignition coils. Especially in older cars, after 30,000 to 50,000 kilometers, the spark plug gap may widen, leading to uneven ignition, making the car jerk when you step on the gas. Another issue could be clogged fuel injectors, where impurities in the gasoline block the injector nozzles, preventing fuel from spraying evenly, resulting in noticeable acceleration inconsistency. If these aren't the problems, you might want to check the transmission fluid—if it's too dirty or insufficient, it can affect gear shifting smoothness. For automatic transmission cars, issues with the valve body or solenoids might be involved, and clutch wear could also cause hesitation. If you encounter this situation, it's best not to delay—take it to a professional repair shop to read the fault codes to prevent minor issues from becoming major ones.
