How often does BMW 5 Series clean the throttle oil circuit?

BMW 5 Series cleans the throttle oil circuit every 20,000 to 40,000 kilometers. Throttle is a controllable valve that controls air to enter the engine. There are two types: traditional pull-wire type and electronic throttle valve. After the gas enters the intake pipe, it will be mixed with gasoline to form a combustible mixture, which will be burned to do work. The length, width and height of the BMW 5 Series are 5047mm, 1860mm, 149 1mm respectively, and the wheelbase is 2888 mm It is equipped with a twin-supercharged inline six-cylinder engine and matched with an 8-speed automatic gearbox. The fuel tank volume of the car is 68L, the maximum torque of the engine is 290 Nm, and the maximum torque speed is 1350 to 4250 rpm. The driving mode is front-back driving.