what is this piece

I don't know his Turkish, but his English wastegate actuator. It is used to adjust the speed of the stands inside the turbo. It does this by adjusting the exhaust gas entering the turbo (no matter how much it enters the turbo or not).

As Koliva says, it adjusts the pressure of the turbo. It is passive at lower speeds, but when the turbo pressure above 3500-4000 rpm rises above the desired value (it should be 0,6 bar), it decreases the turbo speed by protecting the turbo and preventing the vehicle from drowning by making poor mixture (excess air less fuel). The loose piece renders the part 2 unable to perform its duty, putting the turbo at risk and causing pressure loss and lowering the vehicle from traction. The oil of turbo in the lubrication in that area. Certain biktar throwing is normally met according to the life of the turbo. If there is too much oil, turbon engine oil will decrease. 1 lt per 5000km also does not require an emergency response, which can be considered as normal value.

Thank you very much for the information you provided friends