Outback 'whistles' at higher RPMs

[Matt Fischer]

My 2001 outback (45k miles) makes a whistle sound at about 3700+
RPMs. I only get this when passing on the interstate or on hills.
Passengers have describing the sound as coming from the rear of the car,
which points to the exhaust. However alternative theories are that the
fuel system is making the noise.

Does anyone else have this high-rpm whistle?

PS - I have seen reference to this problem before but it was always
diagnosed as an exhaust issue. However, since so many people have seen
it, I am wondering if the problem is more mundane.

 

[Edward Hayes]

I'm wondering if you have a leak in the air induction system. Check
especially the filter air box as if the bottom in not fully
seated/captured by the bottom latches you will get high velocity air
noise. ed

 

[Matt Fischer]

I'm wondering if you have a leak in the air induction system. Check
especially the filter air box as if the bottom in not fully
seated/captured by the bottom latches you will get high velocity air
noise. ed

Ed,

I checked this and everything seems sealed tight. Any other
thoughts?

 

[Bryce]

Is it always above a certain MPH?

Could it be your rack on top of the car?

 

[Edward Hayes]

Yes I remember my rack causing a high pitched noise until I moved the
front bar behind the B pillar. They also must be facing the correct
direction i.e. thick side forward.

 

[Bryce]

Yes. These are airfoils. In fact, I've heard that if you go fast enough,
your car actually loses weight because of the lift produced.