DB9 Top Gear Track
AO Silver Member
Join Date: Jan 2007
Location: United Kingdom
County: East Sussex
Don't worry about it, the suspension was going to start knocking sooner or later. You need to start as you mean to go on, are you the sort willing to have a go yourself or do you have a garage do all you work?
If it's the former there are plenty of guides in the forum for diagnosing suspension knocks and how to go about replacing bits, if it's the latter then you're going to become very friendly with your garage as the suspension is the achilles heel of the 147/156/GT.
Wishones, balljoints and bushes give no end of problems, but usually these cause knocking on uneven surfaces or when braking/accelerating as you describe.
If it knocks/creaks while stationary, or close to it, we can eliminate drop-links, anti roll bar bushes and I would've thought upper and lower wishbones. Usually knocking while turning is CV joint related, are you sure it doesn't make the same noise at all speeds but just easier to hear when going slow?
You could also check the wheel bolts are tight, sounds daft but it's been done.
All the best