While I'm driving I hear a fluttering sound from passenger side of the engine every time I shift (manual) between 1500 and 2000 Rpm. It flutters fast at 1500 and then slows down until it dies away at 2000 rpm.

I have no idea what it could be, it doesn't affect any of the performance or anything, it's just an annoying sound, and no, it's not the VTCs.

Any ideas on what it could be?

 

y-pipe leak?

 

Manifold studs?? Is it worst when the engine is cold.

 

No, I hear the sound when it's cold and warm. Is the Y-pipe stock? because I don't have anything aftermarket on it.

 

It's most likely a stupid exuast leak just make sure she's in nuetral. Start her up and see if the sound is louder underneath the car.

 

Y-pipes are stock.

 

does it kinda sound like a whistle noise , cause i get a noise that sounds like air passing making a whistle noise between 2000-2500 rmps, then it stops in every gear too. i dont know what it is, anyone have any ideas?

 

Nope, it's not a whistle, just a fluttering sound like I said. I'll check to see if I can hear it louder underneath. It's kind of a mystery I guess.