Whats causing this noise? on 2003 Ford F-150 Lightning

My 2003 lightning has a high pitch whistling noise(sounds like a tea kettle) coming from behind the supercharger a little to the right. It only does it idling or when im at a steady speed but when I accelerate it stops. What could this be?

by in Beaumont, TX on February 08, 2012
2 answers 6 comments
ANSWER by , February 08, 2012
pcv elbow may have a vacuum leak causing this. common issue with these motors. Roy
COMMENT by , February 08, 2012
Thanks and if not replaced soon could it cause more of a problem?
COMMENT by , February 08, 2012
it will throw a code eventually. i would get it confirmed asap. Roy
COMMENT by , February 09, 2012
where exactly is the pcv valve. is there a website i can go to?
COMMENT by , February 09, 2012
It is on the passenger side valve cover. There should be a sticker with a diagram under the hood.
COMMENT by , February 10, 2012
It was the elbow thanks but when I took the hose off the intake I noticed just a little oil, was the elbow causing that or is it something else
COMMENT by , February 10, 2012
That is normal due to wear in the pcv valve just replace the valve
ANSWER by , February 08, 2012
It sounds like a boost or vacuum leak