maybe someone can help me with this. so last night and today i thought i could hear an faint, extremely high pitched sing from the motor 4.0L when not giving it any throttle. didnt think too much of it but i can still hear it. so i fired it up and popped the hood just now. the sing is noticabely louder and it sounds like its coming from the back of the engine. the noise is constant when idling, very high pitched ( similar to the mosquito ring tone noise if anyone has hear that) and it doesnt vary in pitch. anybody ever have a sound like this?

 

I have that sometimes, but it goes away after a min or so, and seems to happen more when I have fresh oil

 

ok just changed the oil 2 weeks ago. someone suggested on another site that it might be the throttle body gasket. makes me feel better about it though i thought it might be something developing internally. thanks