so I just bought a 2002 is300, when I bought it I noticed a few clunks but I thought no big deal probably ball joints or something, however I haven't been able to figure it out, I've tested all the joints and nothing is loose. Anyone have any ideas about this? it had bilsteins on when I bought it then I put it on coilovers wondering if it was the struts but it still clunks. Anyone have this problem too? I

 

Check the control arm bushings

 

Front or rear clunks? A lot of people forget to get their sway bar end-links tight when they install new struts or coil-overs. In the rear a common clunk is from the knuckle bushings. Often overlooked and hard to pinpoint for a DIYer. Front is usually in the joints/control arms. Possibly end-links as well. I suggest first going over all the bolts that had to to with the coilover install. Something may be loose and sliding around a bit.

 

Also check the inner bushings for the sway bars where it mounts to the body. My fronts died recently, and I was getting clunks.