That sounds pretty nasty... The secondary air system sounds pretty plugged up.
I've assembled a number of related questions that could be related to this symptom.
Check out the about a rough idle / codes 171 & 174 on a Windstar. This is about a TSB isssued by Ford and the Windstar Intake manifold "isolator bolts", AND a change in the valve cover design that causes lots of oil in the wrong places. Strikes me as something to be seriously looked into for your vehicle.
where is air flow relay on 2000 ford windstar
this model does not have a heater control valve, it has a specail thermostat that controls flow.
If the valve cover is leaking it may let oil flow down the head and make the Head gasket appear to be leaking. Clean the engine and then use oil dye or watch for leaks. If there is a coolant leak it is not the valve cover.
Carbon build up. Sticky or stuck EGR valve. Vacuum supply line damaged/leaking. Faulty EGR valve. Faulty EGR Position sensor/wiring.
Means flow when purge not commanded. Bad or stuck purge valve Broken damaged or leaking vapor control system Bad purge control solenoid.
Check the transmission cooler, located in front of the radiator. Flush the coils with a hose to insure that air can flow to cool it.
i'm not sure but is this orange slugdge dangerous to the tank, my over flow is leaking water too.
It does not have a water flow valve in the heater plumbing.It does not have a water flow valve in the heater plumbing.
2001 ford windstar has code PO401 erg insufficent flow.
The vehicle will surge at idle because of the vacuum leak. If the PCV valve has come apart it will take you 2 seconds to inspect. Just remove it, turn it upside down and look at it. If the spring loaded valve is gone, it has come apart. Try lowing through it one direction, then the other. It should flow fairly easily one way, but should feel somewhat restricted the other way.
out of the over flow
Flow valve for what? Coolant, transmission fluid, fuel, what? You need to be more specific.