When i go over tiny bumps i can hear some rattling/clacking noise coming from the front of the car. THe noise goes away when i press on the brakes..if that helps. It seems like something is loose. Anyone know what it is?

 

is it kind or a clunking from the right front, almost underneth the passengers feet?
if so then its most likley the rack end bushing. i just replaced mine, no more noise and i also had a highway speed shimmy that also went away

 

yup
its coming somewhere from the front....

1.how much would it cost to replace?

2.Whats the worst case scenario if i dont replace it?

3. and is rack end bushing also known as the steering rack bushing?

 

anyone help?

 

noone is going to really be able to solve this one for you, especially based on the information provided- get the car up in the air and have a look.

with that said, if it is a thin metallic clanking/ rattle from the front as you described that is fairly constant and goes away when braking, it definately 'aint the RE bushing. i'll put my nickel on a loose cat heat shield. who wants to raise me? if you can move the shield (the spot welds rust through pretty predictably) just rip the sob off.

if it is a more solid and low "clunk", have a look at the ball joints, radius rod bushings, and other subframe/ suspension bolts and bushings.