ok..here i am again..i have a 99 yukon,, bought it cheap..( 2nd time why so cheap) have a misfire... but this tread is for a powertrain noise... when i get on the gas..right from the get go...i hear what seems to be like a sheeeeeeeeeeee sheeeeeeeeeeee noise... not a clunk... like a messshhhh noise... if i get off the gas,, and keep it in gear even..and coast..it faids away..so it is under presure...it is ??? tranfer case...front dif??? any help would be apreciated...
thanks,Manny

 

manny, did you figure out your issue? I have the same noise that fades when I let off the gas...but I am 2wd