My Subaru is a 1998 Forester and the mileage is at 86000 km.
It is a great car, but the only thing that irritates me is the high pitch
noise of the air inlet fan.
In position 3 and 4 the sound of the incoming air is predominant, but in
position 1 and 2 I constantly hear the noise of the fan.
If I switch to fanspeed position "off" it is a relief to notice the silence
of the stopped fan.
I have tried to have it fixed by the dealer but without any success.
The first time the dealer told me that he did not hear the sound and that
there is nothing wrong with the fan.
The nature of the sound that I hear gives me the impression that one of the
fan blades slightly hits something.
When driving the car the sound is slightly different from the standstill
situation (slightly different battery voltage?).
The second time I asked the dealer he told me that the fan is located in a
place that is so difficult to access that it would cost me a fortune (many
working hours) to find a fix for the problem.

Any comments?

do you have a interior filter? I occasionally get a small stick stuck in the
duct close to the fan. eddie