Loud, high pitched whistle

have a 97 town car, upon start up there is a loud, high pitched whistle/hum(not sure how to describe it) type noise comming from the engine. Possibly a pulley?? it doesnt sound anything like a serp belt its much louder and a different sound. I cant pinpoint where it is comming from. It does sound like the front of the motor. Any body have any ideas? Any input would be appreaciated thank you

Open the filter airbox. Is the noise coming from there? If so, you need to replace your Idle Air Control (IAC) Valve.

If the noise is RPM related, then I'd have to guess a Power Steering Pump Pulley as the noise you describe is exactly that of a Jeep GC I owned.

You have the same issue as me. Check your fuel pressure regulator. That was my issue. That sound is annoying.

Mine was the plastic tube that goes from the back of the engine to the IAC. but I have a older engine design than yours. If you raise the idle up in PARK, dies it go away?

hey guys thanks for all the tips so far. It doesn't go away as I raise the rpms. It seems to get a little worsebut its hit and miss while I raise the rpms

Attached you will find the fuel pressure regulator. Try that and see if that is what the noise is. That was my problem.

hey guys thanks for all the tips so far. It doesn't go away as I raise the rpms. It seems to get a little worsebut its hit and miss while I raise the rpms