[rukywe]

I've got a F30 320d 2012 currently on 113K

when driving around 70mph, I can hear this shh shh shh shh shh sound, this sounds like the timing chain, however when driving at lower speed I don't hear it, not even when the car is idle. there's also no rattle at startup.


Any thoughts ?

[clemsonf31]

Timing chain should be engine speed dependent, not vehicle speed dependent. Sounds more like something in your drivetrain

Max

[agentorange]

Mine has 55k on the clock and doesn't do that. I'd say look for a plastic bag hung up underneath.

Mine has the 55 mph and up low frequency throb. It's either in the driveline or one of the underbody protectors goes into some kind of aero resonance. Third possibility is tires. If I let a little underinflation happen, the noise goes away. Could be because the ride height is different with less air.

[Feddersen]

Noise starts at about 1800 rpm.