What Causes the Jerking Sensation During Rapid Acceleration in BMW?
2 Answers
Car jerking is related to two major components: the engine and the clutch. There are many factors that may cause jerking during startup or low-speed acceleration, such as clogged engine oil passages, insufficient or deteriorated transmission fluid, unskilled clutch-throttle coordination, or releasing the clutch too quickly during startup. Below is relevant information: 1. Jerking during automatic transmission car startup: This is normal, as all transmissions except CVT (continuously variable transmission) exhibit some degree of jerking. However, if the jerking is more severe than usual, it may indicate transmission damage, such as stubborn dirt and impurities inside the transmission, especially when deposits accumulate in the valve body, causing blockages that prevent effective oil pressure regulation and lead to jerking, impact, or slippage. 2. Precautions: Jerking while driving is not a minor issue. Ignoring it may lead to more severe malfunctions in the future. Therefore, if severe jerking is detected while driving, it is advisable to first check the transmission fluid for insufficient levels or deterioration.
My BMW has been running for over five years, and sometimes I feel a jerking sensation during sudden acceleration, as if the car suddenly hesitates. Common causes include aging spark plugs or loose ignition coils, which fail to provide stable ignition, leading to engine vibration; if the fuel injectors are clogged or the fuel pump pressure is low, insufficient fuel supply can also cause rough acceleration. Another possibility is a dirty air filter that hasn't been replaced for too long, restricting smooth airflow. Transmission issues are another major factor, especially when the valve body in an automatic transmission wears out, causing delayed gear shifts and worsening the jerking. I must remind you not to underestimate these minor issues—if left unresolved, they can affect fuel efficiency and even the engine's lifespan. It's best to perform a full vehicle inspection every 20,000 kilometers. Last time I replaced the spark plugs, the problem disappeared, making driving much smoother.
