My 02' S2K with 55k miles has developed its first "problem" (if this even qualifies). Under load/acceleration there is a whistling noise from the engine bay. The car still runs/drives perfectly.

My first though was "vacuuum leak," but I didnt immediatly see anything obivous, and the idle has not changed. Any ideas?

 

Do you have aftermarket intake? I know sometimes at a certain rpm the intake will whistle...

 

If it only happens between 2.5k-3.5k rpm then 98% your good. The air rushing over the plate in your throttle body makes the whistle. Pretty much everyone's car does it, it just depends on your intake set up if you can hear it. When I bought my car with the stock paper filter I couldn't hear it, but then when I put in a k&n replacement, the noise came up.

 

Many s2ks do it, stock intake of aftermarket.

 

its prolly your intake. nothing to worry about.

 

After i installed my k & n fipk i hear it too and its not a problem don't worry about it

 

That's good to know. I have the factory airbox (car is bone stock aside from AP2 interior bits).

Th odd thing is that the car never did it before. It only started doing it in the last 1000-2000 miles.