Mitsubishi Repair: 89 Galant 2.0 SOHC Bolt on front of block, banjo bolt, jb weld

Question
Replaced all 5 belts, water pump and plugs using a Haynes manual.  Before I even started my teardown, it said to empty the coolant from the block by removing the drain plug.  The manual was not clear so I accidentally removed a small plug(bolt) on the  front of the block.  This plug is located slightly below to the left of the leftmost sparkplug when looking at the engine from the front bumper.  It is below the valve cover level(on the main block). I tried to put it back immediately when I removed it but it doesn't get tight.  I stuck a screwdriver in the hole with the bolt out and there is metal stopping it about 1" in.  I've asked everyone(shown pictures), no one knows what this plug is. It was not stripped when I removed it.  Also, Oil drips out under pressure from the hole when I start the engine even with a new plug in it. I tried reinstalling with loctite(NG), I tried retapping the hole to 7/16" which is just above the original metric size. I put in a brass plug with teflon(NG). The entire water pump/belt job went great, this is what I can't figure out.
The original plug(bolt) is approx 3/8"+ and about 1/2 long.
Any ideas would be appreciated.  

Answer
Tom,
From 89-92, the engine used in the 2 liter Galant was also used in the Eclipse.  The plug you removed may have been used on the turbocharger models.  On the turbo model, it would be fitted with a banjo bolt with an oil line coming off it.  It would be the turbo oil feed line.  

If loctite and teflon tape doesnt work, you can try to use JB Weld and a bolt.  Otherwise, you may just have to take your car to a welder and ask them to weld up the hole.
Good luck!