BMW E90 automatic transmission jerks when cold
The E90 automatic jolts when cold, is that normal?
Partly yes. When the engine is below about 60 degrees, the gearbox's warm-up program holds the shifts at higher revs. Below about 35 degrees in the oil, the torque converter lock-up clutch is not engaged. The jolt usually disappears in 1-3 minutes, for some in 5-10 minutes.
What helps if the automatic jerks when cold or at light throttle?
Check the oil level first. A gearbox oil change by flushing removed the 2-3 gear shift clunking in several cars, and resetting the adaptations can soften the shifts. Easing off the throttle at the shift point reduces the harshness.
When does the jerking point to a fault?
If an oil change and the adaptations do not help, or the jerking stays in a gear, the cause can be an internal fault in the gearbox, for example a leaking valve or a solenoid (a valve that regulates oil pressure), or the mechatronic unit. A software update does not fix mechanical faults. Have a workshop investigate.