Sure sounds like the camchain rattle problem: briefly, the camchain tensioners (on the early 2.5's) use oil pressure to provide tension. When engine hasn't run for a few hours the oil leaks out of the tensioners = loose camchains until oil press climbs on startup. Most manuals say don't worry but I agree it's not a good sound for an otherwise smooth engine! New (updated) tensioners are available (not cheap) and fairly major job to install. -include it in Ur LIM cleanup plans! U need all new gaskets anyway!
In the meantime, make sure Ur oil is good quality and topped up and use the Ford oil filters; the anti-leakback valve in most aftermarket filters doesn't "hold" against leakdown as well as the Ford ones.
(I've got new tensioners for my 2.5 with 204,000 Km - t/b installed as soon as the weather warms up a bit!)
Good Luck!
