You will need to check the code and see if this is causing your concern. You may have a leaking fuel pressure regulator or faulty IAC to start with. Lets check the fuel pressure regulator first. It is round and located in top of the engine with one small vacuum line. Remove the vacuum line and look for presents of fuel leak in vacuum line or form regulator. If all is dry lets check IAC.(idle air control) It is located on the intake manifold with a 2 wire connector. Unplug connector and start engine. Compare with how it ran while connected. You may have to remove the IAC and clean with carb cleaner or replace. They say you can't clean it but I have had success cleaning for testing and if cleaning fixes concern then replace with new one in case the valve was damaged. Here is the diagnosis pinpoint test if you want to follow it.
Never clean an IAC valve. Carburetor cleaners and other cleaning agents may temporarily repair the drivability concern, but the long-term functionality of the valve is compromised.
For all drivability concerns, make certain the service writer obtains as much information as possible from the customer as to the conditions causing drivability concern. Attached is a drivability concern check off sheet (Figure 2) that if used, can help reduce the time required to diagnose a vehicle.
Use the following Supplemental information for 3.0L 4V Duratec Engines, in the Taurus/Sable, and Lincoln LS.
If the Duty Cycle is out of specification, proceed with the following steps:
after the last time the engine light went on i went to get the code somewhere else for free it still said as follows -- coolant temputure is always low-
explaination - the powertrain control module vertifies the engine is at proper operating temperture
probable cause check coolant level
does your answer still apply ? thats why i thoughtit was the fault of the mechanics who put the water pump in is . this is a different system ? not cooling