as i have mentioned befor.. it sounds like rocks thrown around the inside of your engine..
pre ignition is a better term.. and self explanitory.. in a nutshell the fuel ignites at the wrong time.. even if only a few mili seconds befor it's ment to.. can be caused by alot of things.. but the number 1 is shit petrol with a car that is tuned, or ment to run on higher octane petrol.. like most new NA 4 bangers require 95 octane min... where as your piece of shit v6 commonwhore engine can pretty much run on kerosene..
