I bought my 08 z three years ago and I love it. However, it's had a weird clunk/rattle noise from both rear strut towers since I bought it. It's only while going below 15 mph, and going over bumps. I stripped out the interior and removed EVERYTHING from the rear. Replaced shocks, and lubricated all moving parts. I'm stock other than lowering springs (noise was there prior to spring installment). I can't figure it out and it drives me crazy. Anyone come across this before?

 

See if you can take it to a dealer and have them inspect the rear strut areas for potential broken weld point. Could be sheets hitting each other when they should be welded in place.

 

I work at the dealership as a technician.. I put chassis ears all over the place and have narrowed it down to right inside the strut tower. However, while taking everything apart, I found a ton of broken glass inside underneath all the trim. I think the previous owner had the rear windshield busted out or something. It drives me crazy. Oh well, I'll just keep turning the volume up.

 

several people have changed the gasket between the shock towers to resolve the issue and others have changed the upper shock mount bushings. Both are fairly inexspensive i would do both.

 

You know, I just reused them and replaced the shock only.. I should've known better. I will order the parts and see if that fixes it.

 

good luck hope it helps.