[rick3000]

There is a faint noise coming from behind the driver's seat on my '99 Boxster. If I put the window down I can't hear it, only when the top/windows are up. It's difficult to describe, similar to a fan blade that isn't balanced properly.

I don't believe the left intake has a fan, could it be the timing belt? What else is behind the driver that could be making a clicking noise at perfectly timed intervals?

I'm coming up on my 75k service, but I am wondering if I should be concerned and take it in sooner. Thanks!