drain plug gasket needed ??

[Jworks]

This may sound like a dumb question to some.  

I have 2011 Sierra 4x4, 5.3 engine, I bought used 7 years ago.  One day I noticed the oil drain plug didn't have a gasket.  I wasn't sure if this model used a gasket or not because the inside of the plug head had 3 tiny raised lines rather than flat and smooth.  I didn't know if this model truck was made to go back on without a gasket or if maybe the plug had been replaced by the prior owner.  Anyway, I bought a gasket and put it on.  Its rubber.  I did another oil change two days ago and the gasket seemed to be torn a little bit around the edge but seemed ok enough to not cause a problem.  My question is does anyone know for sure if this model truck should or should have a gasket ?

[CamGTP]

Factory drain plugs use a seal/gasket.

 

https://www.rockauto.com/en/moreinfo.php?pk=7221372&cc=1446777&pt=10231&jsn=717&optionchoice=0-0-0-1

[richard wysong]

some factory plugs have a groove for an oring, ALL drain plugs have a seal of some type ,the exception being a self tapping repair plug

[Black02Silverado]

Another option is to get the Fumoto Valve.  No more issues and makes oil changes less messy. Plus you can drain the oil when it is still hot without burning yourself.  Plus draining hot gets most of the suspended contaminates out since they don't have time to settle to the bottom of the oil pan.