Howling sound coming from inside

[Helmir09]

Hi everyone, i have been experiencing this howling sound hearing from inside the car. It comes and goes. Sometimes when moving and at time during stationary as well.
Can anyone who have experience such sounds enlighten me on what could the cause possibly be? Im driving a 2011 520i

Thank you!

 

[rssid]

kids or wife ?

 

[Helmir09]

Luckily non of the above but it is very annoying to hear.

 

[Citizen69]

is it the radiator fan that is running at high speed? If so, could be thermostat rosak

 

[Helmir09]

It’s not the fan. Thermostat also just replaced. But thank you for sharing