"Police siren" noise when apply light acceleration

[335e91 3]

Just recently noticed there is "police siren" type of noise only when apply light acceleration between 1600rpm-2700rpm or when let off gas. No noise when parked or Rev up. No engine power reduced or error code. Just wondering what that could be:( . anyone had same issue?

[Michael. 2313]

Could be the diff.

[OP6 27]

The 323 or the 335?

[zero 1162]

You are driving a cop car

[335e91 3]

The 323 or the 335?

335i bro, hopefully it is not the turbo going out:(

[*Glenn* 854]

Turbo / compressor side air leak. Possibly a charge pipe or hose connection

[335e91 3]

Turbo / compressor side air leak. Possibly a charge pipe or hose connection

thanks bro, will get it checked out on Monday

[Cab 148]

You've probably got a turbo that's dosing - is it similar to this?

http://www.youtube.com/watch?v=6qApXcIgrF8

[335e91 3]

You've probably got a turbo that's dosing - is it similar to this?

http://www.youtube.com/watch?v=6qApXcIgrF8

Having trouble opening the link bro

[Olaf 3309]

thanks bro, will get it checked out on Monday

Hopefully you'll be using one of our generous sponsors, such a, well, Botany Motor Worx Ltd, or other companies listed here #8 )

Mind you don't unwittingly pull people over whilst you're cruising around.

[KidFresh 0]

Ok I'm getting this noise too in my 135i. Anyone know what it is .... i always thought it was the turbo spooling up until i read this thread.

Did some research over the net and its apparently shaft play caused by the bearings in the center section of the turbo wearing out over time which can cause turbine failure.

I'm sick of this car; first walnut blast of the intake valves now this. ZzzzZzzzZZ

Edited March 20, 2016 by KidFresh