Hi there!
Lately I found when I'm accelerating and release it a bit, there's a strange whistle. I noticed at about 60mph aprox.
Yesterday night I was driving at about 90-100 and the whistle suddenly became stronger.
I released the accelerator and lowered the speed and it stopped but when accelerating again it started whistling again.
I've got an S JCW R53.
Any ideas about what it can be?

 

Do you have a cold air intake? With my cold air intake I get a whistle on acceleration too.

 

its your intake, when your at full throttle you hear the supercharger more, but at partial throttle the supercharger doesnt boost as hard, and you will hear the intake

 

I had a nick in my windshield. Use to make the car howl on the autobahn when at cruising speed. Nick became a crack; got a new windshield; end of problem.

Might be worth the 2 minutes to carefully inspect the windshield.

 

Loud bypass valve?
Do you own a Gp?

 

I had another whistleling problem with the front windshield and sort it out.
That's something different. I'll check the other options here written.
Thanks a lot!

 

No I don't but I'll check it!
Thanks!

 

I've got the JCW 210bhp kit, so yes i've got a cold air intake. I'll see if that's what you say.
I really appreciate your answers!

 

When I added DDM CAI to my 2004 MCS I got a whistle. I think there are different types of mini whistles but mine was intake related. It was intermittent at part throttle. I've put up with it for about 18m and it went away 2 weeks ago when I added the DT Bypass Valve. My OEM BV had a small 0.5 mm opening when it was supposed to be fully closed whereas the DT BV fully closes. So I'm guessing thats where my whistle was coming from.

 

 

Its thinks your sexy!