So iv had this jeep a couple days, and iv fixed oil and tranny leaks and a water leak..but iv yet to drive it anywhere...but while its idleing after it gets warm there's a high pitch whistle (sounds like a tea pot) around the fan area... Any idea, iv thought maybe some kind of bearing but it also sounds like pressure is building somewhere

 

Possibly your radiator is boiling because the cap is not holding pressure. Therefore, it IS a teakettle!

 

Ok well I did notice the other day the cap kept dripping after I put it back on but it sounds like its coming from the water pump area, but it doesn't spray or leak water anywhere

 

Could be caused by bad idler pulley bearings.

 

Well im going to start simple and just replace the radiator cap.. Also curious...my dad has a 99 dodge ram 1500 with the 5.9 magnum, and it just so happened he has a brand new idler pulley he never used..will that fit on my 4.0?

 

You would have to compare the two and see.

 

Ive heard that type of sound due to a cracked intake manifold

 

interesting, I pressure washed the motor the other day and after a few hrs of letting it air dry I let it run and I did notice bubbles between the head and intake but I couldn't tell if it was heat boiling it off or air seeping out...it only does the whistle randomly....its really not that big of a deal just irritating.lol