At the Cancun meeting of the world trade talks in September 2003, a powerful new grouping of developing countries emerged. Led by rapidly growing countries and major exporters like Brazil, China, India, and South Africa, this group has been powerful enough to challenge the EU and the US in trade negotiations.
If the situation is really bad it can even be caused by the rod itself contacting the crankshaft journal (where the bearing has become out of place). The most common cause of rod knock is due to a spun bearing (bearing itself actually spins in the end of the rod so it becomes out of position).
If a temporary condition caused the knock, the PCM will set spark timing to the. programmed advance. If the knock returns, the PCM will cycle spark timing, advancing. timing until knock is encountered and then. retarding timing until the knock is gone. Ideal conditions would have the spark occur. when the piston reaches top dead center. (TDC).