What Causes the Jerking During BMW 5 Series Acceleration?
2 Answers
BMW 5 Series jerking during acceleration may be caused by the following reasons: 1. Incorrect use of low-octane gasoline: Using low-octane gasoline can result in weak acceleration, reduced engine power, and increased fuel consumption. 2. Fuel pump failure or clogged fuel filter: A faulty fuel pump or a clogged fuel filter can also lead to decreased engine power. 3. Throttle body and air filter issues: The engine requires not only fuel but also air. If components like the air filter or throttle body are clogged or malfunctioning, causing insufficient air intake, the vehicle may experience weak acceleration, slow speed increase, and jerking sensations. 4. Persistent dirt and impurities in certain components: Many cases of jerking or impact in automatic transmissions are not due to internal valve body damage but rather the accumulation of stubborn dirt and impurities, especially within the valve body. This buildup can form blockages, preventing effective regulation of oil pressure and leading to jerking, impact, or slipping issues.
I've driven a BMW 5 Series for several years, and the jerky start-up is quite annoying. The main issue lies in the matching between the transmission and the engine. Although the ZF eight-speed transmission is smart, it tends to develop problems as it ages. If the transmission fluid hasn't been changed for too long, it can thicken, causing hesitation during gear shifts. Clutch plate wear is also a common cause, especially for cars frequently stuck in city traffic, where slippage may occur after driving 70,000 to 80,000 kilometers. There's also the issue of engine carbon buildup; direct injection engines are prone to carbon deposits on the throttle valve, leading to unstable air intake during start-up. Poor solenoid valve performance can also make gear shifts less smooth, which can only be detected through a computer scan. Additionally, the transmission program may need an update, as BMW often optimizes shift logic through software updates. It's recommended to first read the fault codes, change the fluid if necessary, and not let minor issues escalate into major problems.
