2000 Passat sounds like the turbo is whining when the car is started?

Answer 1

I believe that this is the sound of the electric blower motor for the "secondary air injection" (SAI) system. This is an emission-controls system that is supposed to operate during the first 60 seconds of starting the engine, to lower emissions until the engine (catalytic converter?) heats up sufficiently, by blowing outside air (?) into the exhaust system. The reason I know this much is that I have a "check engine" light, whose code says that my left SAI valve has failed. The blower motor still whines for a minute, but I'm guessing that one of the valves isn't working. I'm guessing this might cost a lot to fix, and it really only works for a minute each time I use the car, so I've left it like this.