Okay so after reading about 20 threads on clunks and doing some troubleshooting, I'm out of ideas and need some help. I get a "clunk clunk" in the rear while going over uneven surfaces such as speed bumps on angle or turning onto an offset road. Really annoying noise and sounds like metal on metal.

1) Checked the rear seat latches, drove around with seats folded forward.
2) Checked shocks for leaks, none.
3) Tightened shocks upper and lower bolts.
4) Checked tail light lenses (yes there was a thread where someone's loose lens was making a clunk).
5) Removed rear sway bar until problem is resolved.
6) Checked rear calipers, tightened up all the bolts.

I'm out of ideas, help me out guys.

Update: 09/09/12

1) Checked & secured battery and spare tire.
2) Emptied the trunk.
3) Checked exhaust hangers, metal is intact and rubber donuts are in place.
4) Checked all the push grommets around the rear and fenderwells, all in place.
5) Checked the sub in the trunk, secure.

Update: 09/17/12

Issue resolved:

1) Two loose bolts on driver side door hinge/striker, about 1/3 turn each.
2) One loose bolt on the passenger side door hinge/striker, about 3/4 turn.

Check your strikers guys if you're experiencing weird clunking and can't figure out what it is.

Sway bar is back on as well, no more noises until something else goes...

 

Check that the spare tire and battery are tight!
Check exhaust hangers are not broke or wore out.

Just thought I would add a few!

Another thing you could do is fold the seats down and have a buddy ride in the trunk to pin point the area the noise is coming from!

Thought of another thing you might over look.
The grommets that secure the fender liner to the bumper ,had afew of them missing myself causing the bumper skin to be loose and move back and forth.

 

1) Checked & secured battery and spare tire.
2) Emptied the trunk.
3) Checked exhaust hangers, metal is intact and rubber donuts are in place.
4) Checked all the push grommets around the rear and fenderwells, all in place.
5) Checked the sub in the trunk, secure.

Going to try the buddy in the trunk trick sometime tomorrow, hard to simulate this issue when needed but happens all the time when not trying, typical.. lol

 

Check the spring seats where the bump stops are, mine some how tore and its been making a noise as well

 

From more analysis, seems like the clunking is coming from the doors where the latch mechanism is :-\

 

Put suspension back to stock problem fixed.

 

You really think pedders would cause this annoyance?

 

are you 100% sure its coming from the door latch area? My car makes big clunking sounds and I am pretty sure its because the front sway bar endlinks are broken. Ive replaced them once before and the noise went away. Second set just went bad recently, not sure why. Take a look at those and make sure they are not broken.

 

Replaced those about 3 times on my LS, it was the first thing I looked at. I checked those, cabs, sway bar bushings, strut tops. Definitely sounds like it's coming from behind me. Checked EVERYTHING in the rear and tightened everything up. I get door rub at the top against the body so I'm thinking maybe they're not aligned properly and maybe the striker pin is letting the door ride up on body flex messing up the paint but don't know how to confirm it.

 

I was thinking the ottp sway bar if its not the powell one

 

sunroof shade when its backed alll the way make a clunk on mine.. did you check that?

also check your rear springs insulators they can make noise

 

sway bar is off until the problem is gone and sunroof is closed

 

rear springs insulators did you check those its the only thing preventing springs to touche the car so metal agains metal could be a noise

 

Issue resolved:

1) Two loose bolts on driver side door hinge/striker, about 1/3 turn each.
2) One loose bolt on the passenger side door hinge/striker, about 3/4 turn.

Check your strikers guys if you're experiencing weird clunking and can't figure out what it is.

Sway bar is back on as well, no more noises until something else goes...

 

nice im glad you figured it out cobalts are hard to figure out lol

 

After researching, found my rear passenger door striker is loose and causing a clunk. What size torque bit did you use? Thanks.

 

Ahh I don't remember, I pulled one out of the Wal-Mart toolbox I had and it fit perfectly.