I have a 08 mkx 3.5L. I replaced the water pump and put the car back together. I left the oil drain plug out while I filled up the coolant. The coolant ran out of the drain plug as quick as I poured it. I took everything back apart to look for the leak. I found a small round hole on the back right side of the water pump that was the problem. It looks like a small freeze plug hole. I contacted parts stores, mechanics and ford themselves and no one knows of a plug that goes in there not do they offer one that small. Any ideas would be greatly appreciated.