I'm just wondering what's that sound the car makes when your about to drive off after starting the car. Hard to describe but sounds kinda like a valve.
It's on an IS250 but may also be on IS350's also perhaps?

It always makes the sound for once off until the next restart each time

I know it's normal as other Toyota do it as well - just curious on what it is.

 

I hear something occasionally too... sounds like an electric motor turning on for about 2.5 seconds. Never figured out what it was doing. Maybe something emissions related?

 

fresh air vent?

 

Sound like an electric motor unwinding coming from the engine bay

 

It happens on my 350. After shifting into drive, it's a descending "whoop!" sound. Usually on the first start up of the day.