Q&A

Maybe first have a chemical test known as a "block test" done, it looks for the presence of carbon monoxide in the cooling system which would only be present if the head gasket was blown or mildly blown. The Jaguar 4.0L engine similar to your engine did have water pump impeller failure. Call the Ford parts department ask them do they sell many water pumps for that year/model.
There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online