I did the same thing with my '96 4.6L t-bird. Brought it to the dealer to say "it's ticking" - they checked it out, said it's the injectors and it's normal.

Well, 15 years later, it's still ticking away, just not in MY driveway

My '97 Cougar 4.6L does it, my V10 does it, so ... guess what? Injectors tick

But definitely keep an eye on it, I would.