This seems like an extremely heavy place to put this. Maybe better to check that x/z has actually changed by a full integer before executing this, and that 1 second has passed since last run.

Something like "long lastTEXRun = 0, lastTEZRun = 0, now = System.currentTime();if (x != lastTEXRun && z != lastTEZRun && now- lastTERun > 1000) { lastTEXRun = x; LastTEXZRun = z; lastTERun = now; checkForNewTileEntities();
}