Some oil filters have an o-ring and can definitely be removed/replaced multiple times. This is not about those...
How about the standard flat rubber gasket type oil filters? Specific example would be the 51394 for the '90's Toyota 5S-FE engine, but same general type is used on many cars I've worked on. The gaskets on the filters that come off the car appear to be compressed compared to the new gaskets.
Why do I ask? I just did an oil change on my car and have a mystery oil leak (nowhere near the drain plug or filter of course as that would make diagnostics too easy). My best guess is that it's seeping around the oil filter gasket, and running along something for a couple feet before dropping off as the drain plug is bone dry on the outside (and easily accessible). The filter's in a horrible location, there's no way to see the "top" half of the filter adapter even with the filter off (so cleaning it during the change is done by feel). With the filter on you can't see anything and are left trying to work around a hot exhaust and oil filter with a rag trying to determine if any oil is leaking. So, I want to know if it's safe to remove the filter (that only has 2 minutes of run time on it), re-clean surfaces, and reinstall. Or, will I have to buy a new filter?
