Several recent works propose mobile sink based data gathering approaches to distribute energy consumption in Wireless Sensor Networks. However, mobility based algorithms require the sink to periodically update its location to the network to ensure multi-hop connectivity. This additional information increases the control traffic overhead, and thus energy consumption also increases. In this paper, we propose a distributive energy efficient sink location update mechanism for mobile sink WSNs, along with a preemptive buffering data collection technique. This sink location update mechanism combines MPR based broadcast algorithm with a distributed local repair mechanism, whereby, sensor nodes dynamically control the scope of sink location update messages. In preemptive buffering mechanism, sink's neighbor nodes act as temporary data collection points, referred as roots, to prevent data loss when sink moves out of their vicinity. We show by simulations that our proposal effectively reduces the energy consumption and data losses of the network.