Had a 2007 Silverado with the 5.3 did it every cold start up since ive had it. bought it new and it did that noise for as long as i can remember. Never was a problem.
"if one day the speed kills me, do not cry because i was smiling." -Paul Walker
2011 X25-lots of flake,stereo and ilmor
1985 Stars and Stripes-Ol' glory