[john]

Could be phantom knock. Do another log. When you step on it do you start knocking right away (high counts)? If so, try it again, let off quick, and step on it right away and see if some of it goes away. Do this very quickly. If knock count drops or disapears, it is probly phantom knock caused by too much carbon in the combustion chambers. MCCC would fix that as it did for me.