Hopeing someone can help me out. My radiator is leaking water out of the drain plug. I have replaced the drain plug with a new one and it still leakes. It begins to leak after the car gets warmed up and you turn it off. As long as the car is running it will not leak. After the engine cools off it stops leaking. Also IF there is no water in the overflow, which is not often as this is bad I know, it does not leak. Also it has not overheated, used two gauges to be sure, and I recently (4 mnths ago) replaced the water pump and opti. Any ideas would be appreciated.

 

Probably a crack in the plastic, try some radiator stop leak, otherwise the radiator will have to be repaired or replaced.