Identify this part???

Can anyone help me identify this part? It appears to have a slight seep of oil comming from it. There isn't a drop on my skid but I still don't like that I see it seeping through the side.

It's just behind the oil filter on the left (drivers) side of the engine.

Here's a couple pics

 

Oil cooler?

 

^ oil cooler

 

According to the diagram picture from above ^
It seems that the oil is seeping from #2
Is that a gasket?

Anyone know if I can try tightening the main bolt in the middle?

 

It is actually an "O" ring. Easy enough to replace. Cheap as well. Just take out the center bolt, Pull away from block far enough to replace gasket, and reassemble.

 

Thanks for the help. I'll be doing this tomorrow. Dealer has the O-rings for $8, gonna just go oem since it's lasted until now. Plus it's only 8 bucks