

The oil drain plug just let a little out first to see if there is coolant in bottom of oil pan. When those o-rings go bad it won't stop leaking. Just let it set awhile like a few days and check now and then for coolant on bottom of liner or on the steer axle and floor.

If you don't have a way to pressurize the radiator to make the liner o-rings leak, While you there you can have someone bar the engine over and check the cam lobes for wear. Next thing I would do is drain the oil and drop the pan, roll the engine over so you can look up and check the piston and liner for scuffing and coolant droplets collecting on the bottom of

Well either it has broke some rings on #1 cylinder, or you have some liner O-rings leaking coolant that scuffed the piston and bore, or an injector is puddling fuel at a great amount.
