Could be the head gasket. Very common problem with this engine and model year Windstar.
my 2001 ford windstar is still overheating even though i changed out the thermostat. what could it be?
Is your fan coming on?
are the cooling fans coming on
fan clutch?
Year, make and model would help us help you.
possiable head gasket
have a blown head gasket is my guess
Inoperative radiator fans, bad water pump, failed headgasket?
Could be a collapsed lower radiator hose, perhaps a bad thermostat.
After 10 years radiator may be plugged or restricted - try to flush or boil out May need replacement
Have flushed complete cooling system replaced water pump radiator thermostat clutch fan added 2gal straight anti freeze then filled to capacity with water and truck is still over heating. What else could possibly be wrong
A thermostat is one cause of over heating engines.The "Related Question" below lists a few other suspects to investigate that can also contribute to overheating.