We own a 99 S80 T6 which has been a great car. For years we have heard and felt a popping noise in the front of the car when it is cold and being turned. No one could ever figure it out. Then I found a pdf file online (possibly this forum) which talked about this very problem and how to fix it. I gave the file to our mechanic who I totally trust. He installed new rubber O-rings in the subframe area. Did the entire job parts and labor for $150. Guess what. It worked. The noise from hell is gone. So if anyone is experiencing the problem there is a fix and it isn't expensive. Here is a link to the pdf file we used to fix this annoying problem once and for all.

 

We have a 2004 S80 non-turbo and have beenhearing some similar sounds when we are making left turns. I originally thought it might be a CV Joint in need of replacement, but with only 56000 miles I thought that was premature. How did you rule out CV Joint problems. Thanks for the pdf file that describes the suspension fix. Did you get a look at the o-rings? About how big were they?
Thanks
Placervillebob