newbacca

2000 Boxster producing right front apparently interior ‘ howling noise’. Much like blowing over an empty pop bottle, or like a low pitched flute, also described as a ‘ wooooo noise’. Noise starts at approx 25-45 mph under consistent low engine load. Noise temporarily stops with any deceleration or acceleration. Top up or down; windows up or down; fan on / off; & braking all do nothing to stop or provoke this annoying noise. Boxster blogs recognize this issue, most often thought to be a wind or vacuum- fuel system issue. However I have found no apparent conclusive or verified remedy.
Please advise, THANKS.

ep3_lol

I get this very sporadically, I always thought it was just some aerodynamic anomaly. No rhyme or reason to when I hear it at all, except for its occurring more often with the top down.

Macster

Check the front trunk lid leading edge is *below* the trailing edge of the bumper cover. Also be sure the front trunk lid latch is securely holding the front lid closed. On older cars this latch can wear out and let the lid come up. The safety latch will not let the hood pop open, but it can howl.

Be sure the oil tube filler cap is on securely and the cap does not leak.

In some cases the howl is the result of a bad AOS that actually pulls air past a seal (RMS or even the FMS).

newbacca

Thank you, Macster! I will look into your suggestions. I should have mentioned earlier - I strongly suspect the issue is not wind but vacuum pressure related. Ie any acceleration - deceleration not in speed but in engine load ie vacuum pressure stops the noise. I'm not sure if this will change your diagnosis or not.