2001 Jeep Cherokee Sport - 140k miles

Ok, here is my problem. After the car is warmed up and I drive beyond 3 or 4 miles it makes this high pitched noise that sounds like its coming from behind my steering wheel. But, it only makes the sound when I take my foot off the gas pedal. As soon as I put the smallest amount of pressure back on the pedal the noise stops but starts again when I take my foot off the pedal.

It only happens when I'm moving. It doesnt make any sound when I'm stopped. Im pretty sure the high pitched sound can be heard from outside the cause if I roll the window down I can hear it a bit louder. I will say that what I can hear inside the car is pretty subtle but loud enough to drive you nuts if your not listening to the radio or anything.

Any help pinpointing what this might be would be great.

Thanks!

 

I have the same noise on my 00 but it only happens ever once in awhile I have no clue what mine is either

 

I had same issue on a 1998 4.0. I checked for vacum leak, then tightened intake manifold and it decreased dramatically. Still have a bit of noise. But greatly improved.

 

Vacuum shoots up when you let off the pedal. I guess it's common for the manifold bolts to need re-torquing. (mine did). No clue if that's your problem, but it's something you might want to do anyway.

 

Cool Thanks. I'll give that a try. I'll repost if it helps.