After enactment of a zoning ordinance for the city, the zoning commission may at any time propose changes to, additions to, or amendments of such zoning ordinance, but before making a final recommendation and report to the city council of the city with respect to such matters, it shall make a preliminary report and hold public hearings thereon in the same manner as provided in Section 2.36.040. (Ord. 188 § 7, 1954)