What Causes the Jerking Sensation When Releasing the Accelerator?
3 Answers
Introduction to the causes of jerking sensation when releasing the accelerator in cars: 1. Engine oil passage blockage: The combustion of fuel is determined by the engine's ignition, intake, and fuel injectors, which are also the source of the engine's power. If the intake volume decreases, ignition weakens, or the amount of fuel injected reduces, the power will be insufficient, leading to a jerking sensation. 2. Jerking sensation when starting an automatic transmission car: When wanting to accelerate quickly while driving, you need to press the accelerator deeply. At this time, the automatic transmission will automatically downshift to increase the engine speed. When the speed reaches a certain level, it will upshift. After upshifting, because the speed will drop significantly, a relatively obvious jerking sensation will occur. This situation often occurs in automatic transmission models with fewer gears, such as 4-speed automatic models.
When I first started driving a manual transmission car, I often experienced jerking when releasing the throttle. Later, a mechanic told me that the most common cause in manual transmission vehicles is excessive wear of the clutch three-piece set. You should pay attention to this issue if the mileage exceeds 80,000 kilometers. Additionally, wear of the transmission synchronizer can also cause this problem, especially in cars that frequently accelerate aggressively. Of course, driving habits are also crucial. For example, always resting your left foot on the clutch pedal or shifting gears too early can make the car body shake. By the way, a newly replaced clutch disc needs a break-in period, and there might be some jerking at the beginning. Don’t worry too much; just drive gently for a while and see. If there are any strange noises accompanying it, it’s best to have a professional mechanic check it out as soon as possible.
This jerking issue should be analyzed separately for automatic and manual transmissions. For manual transmission vehicles experiencing jerking when releasing the throttle, it's likely due to worn clutch plates or operational issues. The situation with automatic transmissions is more complex: for older vehicles, it might be time to change the transmission fluid, or there could be a stuck solenoid valve; turbocharged cars often have issues with the blow-off valve or vacuum hose leaks; for fuel-injected vehicles, the throttle position sensor should also be checked. My neighbor's American car had severe throttle carbon buildup causing signal errors, and it was fixed immediately after cleaning. Additionally, vehicles with modified exhaust systems are prone to this issue if the backpressure isn't properly adjusted. If the jerking occurs within a specific RPM range, focus on inspecting the driveshaft mounting rubber and engine mounts. It's recommended to first read the fault codes with an OBD scanner before making repairs to avoid unnecessary expenses.