High pitched whistling noise

There is a whistling noise that is coming from under the hood of my Jeep. It is more noticeable on cold days. It temporarily disappears when my foot is on the accelerator or after I have been idling at a stop sign for 30 seconds. The noise starts again when I start driving.

Model-Year ?
CSA

1995-Jeep wrangler

Can You Tell If The Noise Is Generated By Rushing Air As Opposed To Something Mechanically Spinning Or Slipping Against Another Part ?

You might have to place one end of a few foot long length of hose to your ear and carefully move it around in the engine compartment when the noise is present and see if you can isolate the noise source. Watch out for hot and moving parts ! Stay clear ! Don’t have anything loose hanging from you.

It could be a vacuum leak, bearing, slipping belt, or . . .

CSA

I bought a mechanics stethoscope that I will try to use to isolate. I can not tell what is generating the noise but it sounds like air.

The Stethoscope Will Probably Locate Mechanical Sounds Better And The Hose Will Probably Locate Air Or Vacuum Leaks Better. Try Both. Be Careful.

CSA

I too am experiencing the same issues you’ve posted here “2003 w/ a Squeal” see above