Recent observational studies indicate that the mechanisms of Pacific decadal variability importantly involve the tropical Indian/western Pacific oceans and south Pacific convergence zone. Evidence for this suggestion is sought from the results of a 1000-year integration with the CCCma coupled ocean-atmosphere model which reasonably successfully simulates the principal mode of Pacific decadal-interdecadal variability. Both the western North Pacific, where ocean dynamics act to generate heat content anomalies, and the western South Pacific, where surface heat flux forcing acts to generate heat content anomalies, play a role. These heat content anomalies are advected to and eastward along the equator providing the negative feedback to allow the system to change phase.