When I had a Coyote Mustang alot of the owners complained about this tick after an oil change but it never seemed to effect performance. Never noticed it on my GT or GT500.
You bunch of :bash: after reading this thread I noticed that I too have this ticking sound! Primarily hear it on the drivers side, hear it more when the car is warm that cold. Not sure how long it has been there, but based on my used oil analysis reports I am not worried. It also does not seem to affect anything. Still under warranty so if it is something serious then it'll break before the warranty is up (I have a 100k warranty:banana.
Faint sound, not that loud, definitely valve train noise...