My car is making a strange whistling sound at high RPMs, especially in 2nd gear at about 30. The sound goes away when I shift, and slowly gets louder as the RPMs increase. Anyone know what might be causing this?

 

Probably your intake?

 

if you upgraded your TB sometimes you will hear it whistle. also the tubing that goes from your plenum, has a small square black platic box shape, to the CAI or stock peice, the peice between plenum and black box will sometimes get softer and starts to inclose when you give it gas and causes a noise like that also.

 

The air intake is stock, so I don't think the TB has been upgraded, since they're usually upgraded together. I don't know what the stock TB looks like or how to check if it has. Mostly, I just wanted to know if it was something I should have checked out.

 

If you look at your TB and it says ford on it or looks like a grayish color, probably stock then. check the hose that comes out of the front(as you look at the car) from pleum (behind the TB) that goes to this square or rectangle looking plastic, black box. Start your car, look under the hood and move the throttle linkage to give it some gas, and see if that hoes sucks together and whistles

 

Thanks! I'll give it a try.

 

Your throttlebody will have a mustang pony on it, not say ford.