Hello! First time post. I have a 2000 LS that has 235K Miles. I've truly had to do little but change the oil, brakes, a serpentine belt and a few rollers here and there. The other day the wife was driving it and it developed this squeak. I spent about 20 minutes with a rubber hose trying to pin point it, and it sounds like it'* either coming from the back left injector or its under the valve cover, but I cant quite determine where. I've unplugged the injector cable and the noise didn't go away. I've pasted the video at the top of the post, take a listen and tell me what you think. I'm a pretty seasoned shade tree mechanic and went right for the Alternator or Tensioner Pulley when I heard that noise, but no dice. They aren't the culprit.
Your help is appreciated.