High pitch noise on highway
I have a 2005 3.7l Grand Cherokee, and over the past few months, I have noticed that from about 50-75 mph, it makes a extremely high pitched screeching noise. Today I noticed it goes away at about 80, and it gets a little quieter when I take my foot off the gas pedal. My uncle thinks its the fuel pump and my neighbor thinks its the tires or axle/driveline. It is ear piercing and makes for a terrible commute. Has anybody else had this issue? Please help.