<!-- from fixya rte -->Cluning noise when going over a bump - HHR Chevrolet Cars & Trucks

Some common problems are sway bar bushings, and sway bar links at the ends of the sway bar ( some cars do not have these)

Several things can cause front end noise. Worn control arm bushings, worn or broken sway bar end links, and one of the most common can be worn struts.

Install insulator on both end of the springs . Insure all connection are tight . staby links are common noise maker

Could be a ball joint or the strut.

If you have fitted new shockys I suggest you check the travel of the units as it sounds as if they are bottoming out Pistons hitting bottom of internal cylinder.

Poss broken spot weld in the uni body

Probably the front struts your sway bar links can cause the same noise if they are failing but you should have heard or felt somthing while turning regardless of bumps if the sway bar links were bad. Like the other people said start with the struts.

check the frunt break pads if the pads were ever replaced by aftermarket pads they will make a clunk sound going over bumps

could be the struts or shocks also the spring boots(rubbers that go on the end of the springs) hope it helps:)

There are a few suspension parts that can cause knocking noises. Such as swar bar loose, strut mounts going bad. You should really have a shop do a complete suspension check.