hose (vacuum?) not attached to anything

While working on my daughter's 2001 X5 4.4 I noticed a hose / vacuum line that is not connected to anything.

It's on the driver side front of the engine and runs from the lower side of the engine, passes under the plastic BMW cover, comes out the other side, and just ends (it's the smaller one)

Can anyone tell me what this is and what it should be attached to?

Thanks,
- Bob

Don't know if this is the same hose or not, but I had the front bumper of my '01 X5 4.4i ripped off after being sideswipped by a drunk driver a few weeks ago and noticed a couple of hoses that didn't look like they were connected to anything either. When I asked about them I was told they were the hoses that feed wiper fluid to the headlights w/ wiper blades (mine doesn't have the wipers on the headlights).

Thanks for the reply.

My unknown / mystery hose is engine related.

The pics are of the driver side front top of the engine and the driver side front of the engine looking down; the mystery hose is the smaller one.

Anyone know where I can get a vacuum hose diagram for a 2001 X5 4.4?

- Bob

Anybody our there with a X5 E53 4.4 that is willing to take a peek under engine cover and let me know what my mystery hose should be attached to?

I don't know if there should be a vacuum hose diagram in the engine compartment, but I sure can't find one.

- Bob

That is just a breather pipe.

My BMW X5 (2005) about 108,000 km. recently I can hear whine sound is coming from under the car at driver side when I drive between RPM 1500 and 2000. Would you please let me know the problem and solution.