Can you describe this "water test"? If the headgasket is leaking, then we have an el cheapo headgasket test to confirm. If the UIM/LIM gasket is leaking, then try changing the UIM/LIM gasket. Check out our Duratec Maintenance FAQ.
Duratec Maintenance FAQ
Do the el cheapo headgasket test.
Fill coolant to the brim on recovery tank (leave cap off). Remove all spark plug wires. Remove all but one spark plug and have someone crank the engine. If the coolant bubbles over, there is leak from that portion of the engine (or cylinder). If not, go to the next cylinder, and then the next.... Note, it could be more than one area or more than one cylinder.
