Knocking noises going over bumps can be caused by worn sway bar end links. These end links have small ball joints that become loose and rattle. Replacement is the only fix.Google+
Car Problem Reports
Volvo C70 Knocking Noise From The Front Suspension Going Over Bumps
Volvo C70 Problem
Average Mileage: 52,835 mi (12,500 mi - 100,000 mi)
While watching my daughter drive away down I lane...I could hear that terrible clanking noise. I initally thought "CV Joints/Boots". Dealer determined sway bar links failed inspection. Replaced both front sway bar links. Cost of one sway bar = $82.62, Labor to instal at Volvo Dealer = $94.95. Total Cost to replace = $260.19.
Visitor, 2002 Volvo C70, 100,000 mi
the struts are sound but that knocking sound prevails like something is loose.
Visitor, 2010 Volvo C70
When going over bumps, my car makes this "chinking" sound (like shaking a bag of coins). The dealer first couldn't hear the problem, told them to roll down the window! They found a broker link in the sway bar and replaced that. Still didn't fix the noise. They just replaced both front stuts. Much better, but still making the noise; dealership is trying to duplicate.
Visitor, 1999 Volvo C70, 100,000 mi
When I go over bumps or turn hard right the knocking noise starts. I haven't had it fixed yet.
Visitor, 2012 Volvo C70, 15,000 mi
Still in the mode where I take it to the dealer every few months so they can NOT fix the problem
Visitor, 2009 Volvo C70, 33,000 mi
Thought I was the only one with this problem, good to know Volvo is aware of it--getting it serviced ASAP.
Visitor, 2009 Volvo C70, 20,000 mi
Hear a rattling sound in the front right side when going over bumps.
Visitor, 2011 Volvo C70, 12,500 mi
Knocking and shifting in fromt end at different times. Volvo replacing...stated they are aware of problem.
Visitor, 2004 Volvo C70, 25,000 mi
hasnt been fixed,yet
Visitor, 2011 Volvo C70, 18,875 mi
front right strut making a rattling noise. Had to replace them.