Rough idle

my 04 silverado,5.3 engine idles rough while in drive,sometimes,and then clears up quickly,the problem seems to be randem,help!

A rough idle, sometimes, could be caused by lots of different things. Any check engine light?

Is all of the maintenance up to date? Plugs, wires, fuel filter, air filter?

yes it is! also nothing comes up on the scannar,no engine, there is click that goes off. it seems to be assoc. with the problem