HELP ME OUT TO FIX THIS ISSUE ON MY CAR

[Farsh schafer]

every time when i start my car this weird sound coming , any idea what is it? how to fix it?

[Mr Vlad]

Hello Farsh. Your video is rather noisy with the leather seats scrunching and you fiddling with the trim. Is your car left hand drive? I'm going to jump the gun a little. The is250 when it first starts has a kind of dull whistle. It's nothing to worry about. It should only last 2 or 3 seconds. 

[Farsh schafer]

Hi Mr Vlad, Thanks for quick replay , yes My car is left hand drive. I think the sound coming from AC , the sound kind of like Knock on something 

[Mr Vlad]

A common thing is the exhaust shield under the car. It's strange how it's rattle transmits to a different part of the car.

To check the AC pump I'm not sure where it is but get a long screwdriver and use it as a stephascope and listen for a rumble which means the bearing is on its way out.