[Craig McClure]

Doing my spring maintainence, & one of the issues I'm dealing with is oil sneaking out from under the oil filter cover(that sneaky Mobil 1). I noticed last time I installed an oil filter, that my G5 differed from the manual, in that it has an upgraded filter cover, with a bolt & a spring loaded copper washer protruding from the inside (looks like the pricey one from Hitchcocks) So I'm guessing some of the internal O rings in the manual arent necessary?
  Anyway I re-installed it yesterday. After cleaning the covers mating surfaces, I put it back using silicon form a gasket, instead of the leaky paper gasket. I was very carefull not to over tighten the bolts, which I replaced with some pretty stainless allen heads.
   I'll let everone know how this works out.

[gremlin]

paper ?  gasket ?

if you have the 3-bolt cover, you might investigate upgrading to a newer model.  IIRC mine uses an I-ring in a slot to seal.

[Craig McClure]

My oil filter cover is the 2 bolt one (2010 G5 Deluxe) It does have an a O ring in a flange that slides tightly into the filter cavity. It also used a paper gasket beneath its outside lip-I replaced this paper gasket with silicon Goo-Gasket. Its required 24 hour cure time is nearly over-hope its nice out tomorrow!

[Arizoni]

My 2011 G5 also has the two bolt cover.
The O-ring provides all the sealing that's needed if it is in good condition and wasn't damaged by someone removing it while they were changing their oil.

The thing to remember with these bore fit O-rings is they need to be lubricated before they are squeezed into the bore.

From a design point of view, the only reason for that paper gasket that I can think of is it spaces the cap slightly out relative to the oil filter.  That can lower the bypass pressure a little.
I doubt that this is why the paper gasket is really there though.  It's probably a carryover from the old days when the Iron Barrel used a flat gasket for its oil filter cap.