Cause of Oil Filter system clog?

[CurrentObsession]

1999 Mercruiser 454 mag MPI with typical oil filter mounted upside down up high on the forward port side.

Went to change the oil and filter yesterday and was greeted with a big mess as most of the contents of the filter was not pre-drained as usual. My previous experience with these systems is that 90% plus drains back down to the sump after the engine is turned off. It was a good 15 minutes since I had turned the motor off. I did loosen it slightly to break any vacuum that may have built up. Seems like the return hole down in the bowl of the cast iron assembly was not draining or draining incredibly slowly.

Should I be concerned? Should I try to poke something through? I don't see any obvious obstruction at the top.

 

[JASinIL2006]

My remote-mounted oil filter is always full when I pull it off. It's a 350 Mag engine, but I thought the standard practice was to have a Ziploc bag around/under the filter as you remove it, to catch the filter and spilling oil.

 

[GA_Boater]

If the filter is mounted upside down with the can up, while the oil is being pumped out or drained, punch a hole in the can to allow it to drain.

 

[alldodge]

I don't see an issue, and GA has the fix.

Which filter part number are you using

 

[Oshkosh1]

No issue. So long as you've got good OP you have no worries. I've had some filters which drain, some that don't when mounted inverse.
You can also simply crank the engine over a few times after the sump has drained to pull oil from the filter and eliminate most of the mess.
NO...it's not going to do any harm.

 

[CurrentObsession]

okay
Thanks