Hi,

My 2004 Audi A3 1.6 FSI (roughly 7200 miles on the clock) produces a low
volume whining noise when the engine is idle. It's almost like a light
whistling noise when the car is reving around 750 rpm. If I apply slight
power (without it being in gear), the whistling goes and returns when the
engine returns to idle.

This only seems to happen when the car has been running for an hour or so or
more. Any ideas what this might be please?

Thanks in advance.

...Ray