I have a 2019 Ram Express Classic 5.7, 17,500 miles. I have a high pitch sound that sounds like it is coming from around the transfer case or bottom of the engine. I laid underneath and could not pin-point location. It is a high pitch sound during idle. I Rev the engine and it really does not change sound or pitch. I shut off the truck and it sounds like the last 10 seconds of a balloon deflating, almost sound like it is struggling to get the last of the squeal out. I see a couple of years worth of people hearing this but no one has said what it is.