2005 Ford F-150 Cold start engine sounds

My F150 runs great but concerned about sound I hear at start up only when vehicle has not been run for 2 or more days. At cold start up, there is what almost sounds like a scraping noise for a second or two as the engine first fires. The sound goes away quickly and the oil pressure comes right up to normal range on the gauge. Is this normal for the 5.4 engines? It doesn't do this when truck is used daily.