engine ticking

Hello.
I recently had my front engine cover and oil pan removed and resealed due to leaking. I now notice a ticking sound when the engine first starts and then it disappears after it has warmed up for a minute or so. I never noticed it before, but after any engine service natural instinct has me listening more closely for any potential problems. Not sure if it is the belts, injectors, or valves, but it is loud enough to notice. Any ideas? Did the tech screw something up when he opened the engine i.e. cam or is that normal DI engine noise? Thanks