I have a major coolant leak coming from the location identified in the Hi- res photo taken from underneath the van and an engine diagram showing the location. Note: that coolant was poring pretty good out this capped area, It took about 6 -10 minutes to completely drain the coolant . I was unable to take a photo until it had almost finished draining. I did verified that the leak was not coming from the line above that goes to the water pump, it was completely dry. The leak was coming out of a capped hole (one of three capped holes shown in photo and diagram). It appears the caps are pressed in and maybe replaceable? Does anyone know why it would be leaking here, if it's a big problem or simple repair. Any information would be greatly appreciated.

 

Freeze out plug, aka expansion plug.

 

Those are the block plugs - the bores they plug are originally for cleaning sand out of the block after casting the block.

They can be replaced with new steel or brass plugs of the same size and a thin layer of high temp silicone RTV around the perimeter. Follow curing instructions on the tube of silicone.

You can also use expandable rubber plugs that will seal with about 10 ft-lbs of torque.

In either case, a parts store should have them in stock or available next day. Make sure to thoroughly clean the lip on the block as well, otherwise neither will seal properly.

The old ones can be removed by hitting one side with a chisel to get it to rotate, then pull it out with a pair of pliers.

Expect coolant to drain everywhere once you knock it loose - even the best efforts to drain the block won’t get it all.