multiple problems...

I have a 01 6cyl Taurus SE 3.0L OHV. First off a couple months ago the check engine light came on. I took it to a place to check it and they said it was code P0174 (lean code). Well my husband could not fix that problem because of work. It is making a hissing sound from inside the hood. Sounds like it is coming from someplace by the front windsheld. Husband checked, but couldn't tell what hose it was. Our car is starting to stall after we stop at lights or signs now. Is that because of the code?
Another problem we are facing...cold air is coming from the vents not hot or even warm. Husband did replace the thermostat about a month ago when he replaced the sparkplugs & wires. We have been having problem w/the radiator. It dose not get hot or anything like that, but we have noticed that steam (i guess) comes from the right side of the hood at times. One strange thing that happens is the hot/cold gauge will dip down to C when we turn on the heater. What is going on w/this car? My husband wants to try & fix it himself but where to begin? :shakehead Thank you!

You should visit the Sticky from the Taurus main forum page titled "Codes P0171 and P0174."

As for the lack of heat, I was ready to suggest you search the forum for "water pump" to read all the stories about impellers failing, but since you mention that the guage drops to C when you turn the heat on, my first suggestion would be to bleed the air from the cooling system. It sounds like you may have a big air pocket in the cooling system.

-Rod

Yes, your stalling is because of the air/ stalling/lean code. Depending on the timing of the spark plug change and the lean code 0174, your problems could be related. Strange you didn't get another code that would indicate that both sides of your engine are getting too much air because of the vacuum leak you hear hissing. Rod directed you to the common problem of a cracked tube to the PCV. Not sure for that year if the pcv is on the front or back valve cover. It probably was on its way out even if your husband bumped it. If that is the only problem, it probably will also clear up the no heat problem inside as vacuum is used to operate the hvac system blending doors. It may be possible your husband bumped the vacuum line that goes through the firewall to the hvac. It commonly enters as a small tube near or at the heater hoses to the hvac. Get rid of your hiss/leak, you'll take care of things. Can't remember if you will need someone to clear the codes for you, if they go away on their own or you can pull the battery cable, which some don't like as it erases the "learned" unique operating parameters of the engine.

One way to check for air in your cooling system, grab the upper radiator hose. It should be firm and you should hear and feel the fluid inside. Air will have to be bled at high points in the system, tstat, upper rad hose, heater hose, rad cap...you need to judge. Sometimes elevating the front of the car will help with this and deciding where to let the ari out. Add coolant to push the air out.

To convince yourself you are getting hot coolant to your heater, grab BOTH hoses. They should be good and hot. Not sure about the cold radiator and steam unless that is coolant steam you can smell. You may have a bad radiator cap that isn't properly closing. It be trying to burp out the air trapped in it. Are you loosing coolant. needing to replace it, overflow reservoir emptying?

Our Taurus is finally back to normal....hot air & all! Husband replaced the water pump (making a squealing noise all the time). Then he replaced the whole PCV & hose (a crack was on the old elbow part). Code 0174 is now gone. A vaccum leak was the cause of no heat in our car. Thanks!

Glad to hear it. Thanks for the follow-up post!

-Rod