I am concerned that it may not be knocking that you are hearing at all, but something mechanical. It’s also possible that it’s just a swinging heat shield.
Normally knocking occurs more with more throttle, rather than more knock with light throttle and less with more throttle. At low throttle, the effective compression is low and much less likely to cause knocking. That’s why this mostly happens in small displacement turbocharged cars, where the turbo is activated at relatively low RPM by getting extra fuel and air into a cylinder while the engine isn’t revving very fast.
Is there any way you could make a video and provide a link to it? If the hood is open, at idle, or if someone revs the engine, is there any of that knocking noise?
