Grab ahold of the opti drive-shaft and see if it will wiggle. I bet it will.

Not everyone plugs the hole. But, it will be a potential oil leak.

 

I think it's pretty easy to damage the water pump drive seal during installation. I replaced mine last week and it was kind of a pain in the butt to install. The opti seal was pretty simple.

 

Okay, try to stay with me on this. This is how you're getting oil in your Opti, but only on the optical sensor side and NOT on the cap side.

During NORMAL operation of the vented Opti, fresh air is drawn through the distributor cap hose rubber tube into the Opti and removed from the Opti by the vacuum hose tube connected to the metal base of the Opti, right.

If however, the gasket between the phenolic distributor cap and metal base is compromised (i.e. broken, missing or leaking) .......... the vacuum supplied through the Optispark base takes the "path of least resistance" and "vacuums up" the air leaking past the cap/base seal. Got it so far.

Now if ANY of those three(3) seals in the timing cover are leaking oil, (i.e. the water pump drive seal, (in your case, the unsupported "dangling" WP drive seal ), the Opti seal itself, or even the crank seal); any oil "wetting down" the timing cover, gets "vacuumed up" past the leaky cap gasket and runs though the Opti's back, (i.e. optical side), side toward the vacuum hose connection in the metal base. This leaves the cap side dry (no oil there!) while soaking the Opti with oil just where your photo's show. Mystery solved!

When you take this all apart........in addition to replacing, (at the very least), ALL the cover seals, (and hopefully(???) even removing the timing cover, WP drive gear and shaft, and "plugging" that now unused WP drive hole, (thereby eliminating that source of leaking)), also check and/or replace the distributor cap to Optispark base gasket and make sure the cap is on well/correctly, and airtight!.

 

Makes sense for sure, thanks for the in-depth post....I'm tearing it down today.