When they don't feel like making noise and at night.
Lubricate.
making
Unplug it.
Bleeding the air from them usually helps.
either replace them or add motor honey to go for a longer perion without noise....
Racket
u tell me
If you get a noise complaint letter then it is best that you stop what ever is making the excessive noise. If the noise is violating the noise pollution law, then you have to stop asap before the police get involved and you get fined. If it is not breaking the law but it is annoying the community then it is best to stop anyway or you will end up with other issues such as neighbors damaging your property when you are not at home.
you cant. the sound is probably either a disk spinning, or the fan running so the machine doesnt melt. if its not making noise, its probably off or broken.
Where is the noise coming from? Under then hood, or interior?
make sure your computer is unplugged and remove the fan from inside, and thoroughly clean it. this will "lessen" or remove the windy noise.
You can stop it by parking in a garage or carport