I would start with upper shock bushings. We sell a kit that does both sides for $75. The bushings must be pressed on the old upper shock plate.

 

the sound can easily be transmitted along components to sound like its coming from somewhere else,

i would look at the upper shock bushing, but also the anti-roll bar link bars at the front , these can look ok, but can be quite loose and worn ,

another possibility os a worn U/J on the lower steering column, these are known to fail, and a genuine Jaguar replacement is sold with a revision to the design , but its a big job to complete....as the whole lower section requires replacement

BB

 

The noise is probably in the column. A part that has causednoise in the past is the cassette, it will cause a clunking sound when the wheel is turned if it is failing. The column needsto be disassembled anyway, just check it out.

 

Did you resolve your knocking noise ? Any details ?