[leejon75]

I own a 2004 automatic Mazda 6 GS.

I've recently started hearing a whistling noise when accelerating at high speeds. It's heard especially when I gun it, mostly between second and third gear. It sounds like a loud sucking noise. I do need to get a new air filter but i'm wondering if there's something more to it. Any thoughts on what it could be?

 

[MonoxideChild]

the stock intake can whistle. ive noticed it with mine before i installed my cold air intake. specially at higher RPM's.

 

[madman4949]

I have this whistling sound between shifts as well only after WOT acceleration. Sure sounds like a vacuum leak to me. Anyone else have this issue?

 

[FLsimon305]

exhaust leak?

 

[6Y MAZDA]

maybe you secretly have a turbo and thats the whistling youre hearing?

 

[TB_]

Have you checked that your airbox is closed properly? Is the air intake bellows properly sealed to the airbox and to the throttle body? Are all air connections to the bellows and airbox connected properly? Any splits or brittleness? All things to check...