Oil leaking from base/gasket.

[Korean_redneck]

Thers always very little oil leaking. I used Valucraft, AAP, Purolator, Fram Tough Guard, Hyundai filtesr.. all of them leak.. all of the gaskets were fine. I tried doing hand tightened..still leaks.. tried tightening with a oil filter wrench.. still leaks.. what could be wrong?

 

[Jonny Z]

How is the boss finish where it mates to the gasket? If there is a deep scratch it would do it. Perhaps there is machining defect and that flatness is out of spec? What kind of car?

 

[kenw]

add to the above list of potential causes:

A bent threaded shaft will cause the filter to seat crooked and not seal.

A buildup of crud on the gasket seating surface.

 

[Filter guy]

Filter mounting base surfaces are to be machined smooth. It could be yours isn't. A rare occurance but not that uncommon.