What causes the jerking when starting with the CVT transmission in the Audi A6L?
2 Answers
Audi A6L's CVT transmission jerking when starting may be due to issues in the engine's oil system, ignition, or intake systems. Possible reasons include sludge in the transmission oil circulating within the transmission, which can block the oil passages in the valve body. Over time, this can lead to a series of transmission problems such as overheating, impact, and slippage. The reasons for jerking when accelerating are as follows: 1. Clogged oil passages. It is necessary to clean the oil passages, fuel injectors, oil lines, and oil pipes. 2. For automatic transmission cars, some jerking during start-up is normal. If you want to accelerate quickly while driving, you need to press the accelerator deeply. At this point, 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, it will produce a relatively noticeable jerking sensation. 3. The combination of auto start-stop and dual-clutch transmission inherently has this issue. 4. Abnormal ignition. It is necessary to replace the spark plugs or ignition coils. 5. Jerking in an automatic transmission is often not due to damage to the internal valve body but rather due to stubborn dirt and impurities inside, especially when dirt and impurities accumulate in the valve body, forming blockages that prevent effective regulation of oil pressure, leading to jerking, impact, and slippage problems.
I've been driving an Audi A6L with CVT for over a decade, and the jerky start is quite common. If it happens with a new car, it's most likely due to poorly calibrated transmission control software, just like a laggy phone system that needs an update. For cars with tens of thousands of kilometers, it might be necessary to check the wear on the chain and cone pulleys. During city traffic jams, if you frequently accelerate hard from a standstill, the chain engagement can become unstable, leading to jerking. Additionally, in cold weather, the transmission fluid thickens, causing slower hydraulic response, making cold-start jerking more noticeable. My solution for my own car is: regularly change the original CVT fluid, and during each maintenance, have the technician read the transmission data stream, focusing on chain pressure and RPM deviation values.
