I made a thread a while back about a rattle sound my car was making. I can still hear it while making a spirited right turn. The sound comes from the left rear of the car and sounds like a metal on metal rattle. I thought it may have been the left rear wheel bearing so I jacked the car up and it passed the tests. While looking I noticed that the left upper ball joint looked different then the passenger side. The passenger side looked healthy and mushroomed, while the drivers side looked flat. Could a worn ball joint cause this noise? Also, what are some methods for trouble shooting it?

 

I don't think a bad ball joint would be audible, you might be able to jack the rear up and try to see if there is any play in the suspension. It wouldn't happen to be a clicking noise, that would indicate a bad CV shaft. Does it only do it on hard corners? Do you have aftermarket wheels? it may be tire rub, I know mine made a god awful noise before I trimmed the bumper tabs.

 

I jacked the car up and could not see anything; this is driving me crazy! The car is a 2002 with 50k miles. The noise is not a CV. It does sound like something is loose that sould not be. I wonder if something is not torqued to spec? Also, it is not the spare tire. I tightened that down.

 

I assume the car is stock ride height, parts, etc. To correctly check the upper ball joint, lift the rear of the car and put it on jackstands. Now put the jack on the lower control arm as close to the wheel as possible. If nothing else under the shock. Jack it up so that the suspension compresses an inch or two. Now grab the top and bottom of the wheel and shake up and down. Try specifically to pull up on the wheel push in at the same time and release. You may need a second set of eyes to see movement if it is only slight. Otherwise, you can definately feel a moderately bad one. Also, check the one on the inside wheel to your turn (the right side) because unloading the ball joint can cause the noise to come about.

This noise could be a number of things, doing some specific driving tests can help isolate what exactly is causing the noise. Try reproducing the noise by going over a speed bump with only one side of the car, then the other.

Worst case scenario, take it to the dealer lulz.