3/4" valve makes a rhythmic clunking noise instead of closing?

When my zone watering time ends, instead of the valve just closing, the valve makes a rhythmic cluncking noise and doesn't turn off. I have to manually shut off the water upstream via the manual safety valve. When I do it finally stops. I've replaced the valve already but I have the same problem. The selenoic is the only part I didn't replace. I just unscrewed it from the old valve and then screwed it into the new one (save time on rewiring).