oil leak showing under oil filter adapter/housing

[Andreas68]

Have a small oil leak that you can feel (can't see it because of the location) under the oil filter housing and eventually drips down the aft side of the cowl onto the ground...slight amount of oil clinging underneath the oil filter adapter/housing after each flight. I've tightened every nut and bolt I can see in the oil filter adapter including, obviously, the oil filter itself (recently changed the oil but had the leak before then). It's not coming from the bottom seal of the filter. Any ideas on what might be the source of this small leak?

Andreas
RV-7A
Aerosport O-360 (1000 hrs)

[Steve Melton]

Originally Posted by Andreas68

Have a small oil leak that you can feel (can't see it because of the location) under the oil filter housing and eventually drips down the aft side of the cowl onto the ground...slight amount of oil clinging underneath the oil filter adapter/housing after each flight. I've tightened every nut and bolt I can see in the oil filter adapter including, obviously, the oil filter itself (recently changed the oil but had the leak before then). It's not coming from the bottom seal of the filter. Any ideas on what might be the source of this small leak?

Andreas
RV-7A
Aerosport O-360 (1000 hrs)

a neighbor spent about a year chasing a similar oil leak. it turned out to be a pin hole in the oil adapter casting itself. the pin hole in the adapter casting was on the lower right side, aft looking fwd.