Sounds like I may have a rusted freeze plug. The flywheel cover is draining quite freely through the hole in the bottom. The only time it runs is after cranking the engine, so I don't think it's rainwater. Does the stop leak really work without causing any damage? I know we used to use it on our old tractor's back on the farm, but I was not concerned about long term effects. The stop leak sounds like the easy way out until I feel like pulling the tranny and flywheel to replace that 50 cent plug.