Q: 2005 Kia Sorento EX 3.5L eng. Problem: coolant leaking below the air intake. I replaced the "O" rings on large and small water

2005 Kia Sorento EX 3.5L eng. Problem: coolant leaking below the air intake. I replaced the "O" rings on large and small water pipes. I replaced the gaskets on the components around the thermostat. There are no water hoses leaking into the compartments below the plenum. The leak seems like it is coming from the area just below the small water pipe "O" ring in the front of the engine, but I can't observe it when the engine is running. The coolant leak runs towards the back of the engine and spills from the top and back of the transmission. I think the leak is coming from the area below the small water pipe "O" ring. What do you think? And, what would I need to do? Thanks.

My car has 215000 miles.
My car has an automatic transmission.