Car has a S2 Alpha 68mm tb mated to a Victor X intake mani. Once the car reaches operating temp, and sitting at idle, there is a high pitched whistle.

The noise goes away under load, and when the gas pedal is "tapped", but returns once I come to a stop. According to my AutoMeter vacuum gauge everything is fine and there is no sticking or drivability issues. The car idles, acts, and performs as normal, minus the noise.

These parts have been on for roughly 1K miles, bought new, and this recently started out of nowhere roughly 10 miles ago.

I've googled, searched, etc. to no avail.

Help please!

 

Anyone?

 

I came across an article once that said the whistle might be due to the TB size not matching the intake mani size, creating a whistle. So I am assuming it should be 68mm across TB and Intake mani. Anyone else have any ideas?

 

High pitched noise has to be from a tight space that's sucking in air somewhere. Test for leaks, spray come carb cleaner around and see if you get some indication of a leak. However, if the suction is strong enough to make a whistling sound, I would think the problem would be fairly easy to identify.

 

A lot of setups do this. Nothing to get too bent out of shape about. Air at idle passing across a surface just right to make a whistle. It's not a sure fire sign of a leak or problem.