well i have the same problem, if u push the front of the car either side you should heard a crackling nois when the car is coming up or so, im guessing the suspension is due, thats if u live in a city like chicago who have alot of pothole problems

when its hot, that noise gets really anoying, and i would replace that after i figure what i have wrong with my o2 censors or whatever it is

 

i can finally put this thread to rest as i have found and fixed the problem.... stethascope was a priceless addition to my tool chest, pin pointed the issue immediately. my Alternater was crapping out, now i'm just pissed that the mechanic that changed my T-belt and installed my underdrive kit didn't notice the grinding noise coming from the alternator while he had it OFF the car.... so i replaced it myself actually was able to pick up a nice reman. at a local parts store. install was maybe 2.5 hours. the tech article i found on here was awesome, and made it possible without a huge headache. so now my only problem is getting the underdrive off the old alt. and swapping it on the now installed new alt. so i can getmy $80 core back.but i need an impact gun and the special torx bit to do that. so all is well, car is purring once agian, and i can sit at idle without being embarrased