I am not sure as to the suspension code but I have the 2LT. I can hear and feel the noise on straight roads at low speed and in cold weather, it seems to come from below the floorboard. I think I may now be able to notice it to a lesser extent on the highway but am not sure. I have had it in a couple times the dealer has noticed it but could not track it down, they tried something and with the return of cold weather it is back. I would like to take it back in since it is a cold weather thing that limits the time to tell if it is fixed before warranty runs out.

 

well brought it to mr goodwrench and samething, they heard it but couldnt locate it. Have an appt at friends shop today to get it in the air and look. all my sounds are on straight roads at both slow and high speeds. wll check it out and let you know.

 

That would be great. I saw ChevyMgr had some suggestions and would like the input. I want to try to get it in the week after Christmas and hopefully get this fixed.

 

Sorry still not on the lift yet was working all weekend and my buddy was tied up with the lifts this weekend. Soon soon but man this noise is driving me nuts.

 

2006 hhr lt
yes i have heard and experienced the same . Only in cold weather below 30 degrees . Most noticible on slow front end compression and release . I am able to duplicate the problem over speed bumps or driveway exit and entrance and on highway dips daily . After 5-10 mile the noise goes away. Service performed on sturts twice. Replaced front struts at 36k in warm weather. Now at 46 k and cold again noise returned This time diagnosis is rt front swaybar link . I was told Part was on nation wide back order. part is in . taking it in this week will update on install.

 

I was just getting ready to take mine in. At low speeds when cold it is almost a rattle, but more of a clunk. Glad and unhappy to see others are having the EXACT same thing happen to them.

 

my wife had said the same thing too, right side, clunking sound, i never heard it when i drove and she has not mentioned it in months so i dont know really what the deal is

 

There are many posts here on this problem if you do a search.
As I have said before, I have had this problem on 3 late model GM vehicles. In every case they said it was the strut mounts that dry and shrink under certain conditions. They lube it with some kind of rubber conditioner that restores the condition of the mounts. However it will always come back at some point. This is one of a few "unsolvable" problems Ive had with GM vehicles, none of them major, mostly annoying noises like the dreaded piston slap.