V6 TDI Turbo Whine: Vacuum Pump & 1800 RPM

Hello,
"I've actually always had a squealing noise at 1800 RPM. It also starts to smoke in that range. It's fine above that, and also below. I now have 280,000 km on the odometer. The VTG (Variable Turbine Geometry) is very smooth. I checked it by unscrewing the vacuum actuator; it moves freely without any resistance."
I've noticed that the vacuum diaphragm can be moved manually by about 3mm when it's not being actuated. When I try to move the valve (VTG) with my finger, it moves about 3mm easily, but then it becomes difficult to move further. So, my question is whether the spring might be broken or weakened. It's definitely sealed.

Could someone possibly check if the steering wheel can be turned manually at the beginning, and then if it becomes impossible to turn because it's too heavy? (Referring to a V6 TDI vehicle)
Sure, I'd be happy to.

Sure, no problem.
Hi Chris,