Keith, like Jay I cant think of any unthreaded port back there. The oil temp port has machine threads, the tach drive has male machine threads, all else is NPT.
The temp port takes a AN crush washer, the tach drive should have a seal around the shaft and/or have a cap on it.
And as Matt mentioned and Im sure you know, oil can appear in strange locations far from the actual leak.
Do you have a Casper labs or B&C filter adapter on it?
On Sep 19, 2021, at 10:06 AM, Keith Spreuer <kspreuer@...> wrote:
I have a new and significant oil leak. I haven't confirmed yet but think it is coming from a port on the accessory case just left(airplane left) of the oil filter adapter. I attempted to plug this port with a plastic cap and suspect that cracked. This port has no threads and I have no idea what it is for. Question what is it for? Should it be plugged? How? If you don't know from this description I send photos later