See also:

Observe the following when refueling
The fuel tank is full when the filler nozzle clicks off the first time. Handling fuels Obey safety regulations posted at the gas station. ...

Checking the coolant level
1. Do not open the hood until the engine has cooled down. 2. Turn the expansion tank cap counterclockwise slightly to allow any accumulated pressure to escape; then continue turning to open. ...

For the 530i, 535i, 550i, 525d, 530d and 535d: check oil level
The concept The oil level is monitored electronically and displayed on the Control Display. Requirements ▷ The engine must be running and warm after the vehicle has been driven for at lea ...