Have some problem with which OIL DRAIN PLUG to use on the pan?

I used the larger rubber seal on the pan and always had a small
oil leak.
Was ready to drain the oil pan and noticed the plug screw was not
real tight. I know I tightened the screw seal and screw.


When I worked at the dealer we got a NEW plug/washer with EVERY oil change.

They are not that expensive but check the seal everytime if you are going to re-use more than once.

Thanks for the Reply, I always use a new screw with a new
washer, they seem to work loose.
It could be the temperature difference.