My '13 would randomly tick (as you described) initially during startup (warm or cold startup) within the first 100 miles after purchasing new. Didn't matter what the exterior temperature was, ranging from 100+ to -35. I decided to change the filter out with 2,200 miles clocked, and since then, no ticking at startup. I chalked it up as a "possible" defective bypass valve. 1,200 miles later, still no issues.