What are causes for no heat problems in a Ford Taurus - blowing cold or lukewarm air only?

Answer 1

These are common causes of 'no-heat' when the coolant is flowing:

1. Blocked / plugged heater core

   To check - confirm that both heater hoses going into the firewall are warm. If only one is warm, likely there is a blockage and the core will have to be flushed and/or replaced.

2. Temperature blend door is stuck in the cold air position
   • The door itself is binding and not able to pivot.
   • The blend door actuator has failed - see "Related Links" below for the Autozone.com online repair guide to replacing the blend door actuator / motor. It's only about $15.
3. Water pump - (see way down below) The water pump kind of self destructs on the inside without leaking out the weep hole. The fins just fall apart and you lose heat for your heater and the engine will overheat too.

If your Taurus is only blowing cold air:

Check the level of your anti-freeze, and make sure that its level is normal.....

1. Open the front hood....

2. Look at the anti-freeze storage tank (white plastic tank on the left side of the engine compartment as you face the front of the car). Check to see where the level is and make sure that it is in the recommended temp zone of Hot or Cold.

3. If the anti-freeze level is in the recommended zone, then the thermostat might be shut closed and not letting the fluid flow freely to the engine. If this is the case, the thermostat has to be replaced. But if the thermostat is stuck, the engine will be overheating anyway, and you'd see the temperature gauge on the dashboard getting up to a dangerous level.

More input from WikiAnswers contributors:

• I just bought a 99 Sable and was told by the seller that the heater core needed to be replaced. The cost being $500. My beloved mechanic that I have brought my 97 Status to for the last few years said that the core didn't need to be replaced, the core was so clogged that they had to flush it twice, which saved me $350. Unless you absolutely trust your mechanic like I do... $350 difference.. We were both expecting a replacement... ask for the heater core to be flushed before jumping to a replacement. Always check for clogs.

• Check how high the temp gauge goes. if it doesn't go above 1/3 of the gauge, change the thermostat or check the tap unit on the firewall.

• If the engine comes up to proper temperature: - The heater core might be plugged. Pull the 2 hoses off the heater core on the firewall, then take a garden hose and flush all the muck out of the heater core, and you might then have heat. - The blend air door might not be opening all the way. Check under the hood near the blower motor--there is a vacuum line there, check to see if it's getting vacuum.

• If you flush the heater core and rust comes out, this is usually the water pump's impellers/fins/blades having rusted and broken up, so you should replace the water pump too or the heater core may become clogged again. For some reason, many water pumps are made of a metal that rusts (it's about the only metal that rusts in the entire cooling system), though you may be able to find replacement water pumps that don't have rustable impellers.

• It could be a bad temp blend door actuator, or I have see a lot of those getting rust in the cooling system and clogging up the heater core.

• I'm assuming it did this before you changed the thermostat too. If not, maybe you installed the thermostat upside down. If all is well I'd suspect your heater control valve. As I recall it's vacuum operated so check the vacuum line for cracks/breaks. etc.

• You might wanna think about replacing your heater core. I've had this in the past and it meant the heater core died. After replacing it, it worked just fine. It can die without blowing anti-freeze foul smelling smoke everywhere. That just means it cracked. i get warm air, but LOTS of smoke lol. It could also be that your water is not circulating right. Have you checked your water level? If you do not have a full radiator, it will NOT blow hot air. I've had many problems with cars in my life. Any more questions on Taurus/Sable, feel free to ask me.

• First, flushing heater cores rarely works. The passages are too small. We just replace them. Further, even if you do flush out the core, if you don't flush out the rest of the system, the core gets stopped back up the first time you start the engine up again. Another possibility is that, if the system is or was rusty, the impellers could be rusted off the back of the water pump, and you have insufficient coolant circulation. We see a lot of that here. Another thing that could be your problem, is that you have a temp blend door stuck or the motor that runs the temp blend door is faulty. The dash has to be removed to access either of those two things.

• Are you saying the blower motor does not work? If so, then the blower motor, fan switch, temperature blend door, or the resistor pack is bad, or a fuse is blown.

• If you have checked the temperature of the heater hoses and it appears that heat is being delivered to the core, the problem is most likely with the air flow through the core, not the core itself. The air flow is controlled by the temperature blend door, and this door has a history of failure on the Taurus and Sable. Replacing the door is a fairly involved process and expensive at the dealer. There is a DIY system from HeaterTreater that will help you with the diagnostics and fix. Check HeaterTreater.net for pictures and information. We have a video posted in the Tech section that will show you how to disassemble the center dash console and check for blend door problems. It is a common failure on the Taurus/Sable for this door to break and fall to the bottom of the box, blocking heat. The HeaterTreater is an innovative method to extract the old door and replace it with a metal door that will not break again. The advantage is that it is not necessary to remove the dash and plenum box to do the fix. Full details are on the site.

The video posted on the HeaterTreater web site in the TECH section will show you how to access and diagnose blend door problems without removing the dash panel. You do have to remove the center instrument console to get a good view of the plenum box. The hardest part is pulling the radio. It requires a special tool to release the catches on both sides of the radio. You can purchase the tool at any auto parts store or make your own out of a piece of heavy wire bent into a U shape. Or...find your local car thief, they can pull one in seconds!!!

The other thing you want to be sure of is that there is no air trapped in the coolant system. On a cold engine remove the radiator cap and check that the radiator is full, not the overflow tank, the radiator. If air is trapped in the system, it will affect engine cooling efficiency and the HVAC system.

• You may have a stuck temp blend door in the heater case or the motor that runs it may be faulty. To access either of those items, the dash needs to be removed. The heater core could be clogged, that's what happened on our '98 Taurus SE. Also check the coolant levels and see if it needs to be flushed or topped off.

• Various cars have various ways of making hot and cold air. Most everyone uses a set of air vanes to switch between hot and cold. Some cars keep the A/C on in the defrost setting. Bottom line here is that it sounds like your A/C clutch is not turning off and the cold air is outdoing the warm air.

• On mine, the heat stopped working and I replaced the thermostat and the heater core was replaced, and it turned out that it was the water pump. Try replacing that. It worked on mine. I even went as far as replacing the radio console.

• The first place I would look is the heater core. My own experience tells me that yours might be clogged. If you have hot water going in and coming out of it but no warm air flow, then I would start there. Until you confirm whether or not the core is clogged then you are wasting time and effort trying to solve this one.

• The good news is that it might open up with an acid flush. I tried that with my Taurus and had some success with it. I did eventually have the core replaced. They are aluminum and hate it when you have an open cooling system (mine was open due to a cracked reservoir that I didn't know about). Corrosion and mineral deposits get in there and kill the coolant flow. This is why using distilled water for your antifreeze/water mix is preferred over tap water. I hope this puts you on the right path to solve this one.

• What both of your problems probably are is a clogged heater core, it happened to me and upon investigating I found out it was ridiculously common for that make and year range of Taurus to get its heater core clogged up with rust. Ford even put in a bypass on the heater system so that the whole cooling system wouldn't get clogged. What you want to do is let the car run, then locate the two hoses that go into the top middle of the firewall, just below the windshield--most likely one will be hot, which would be the input to the heater core, and the other cold, the heater core's output. If both are cold, it may be because the core is clogged.

• I have a 97 Taurus GL Wagon that has the same symptoms. I have been searching for the solution for a few days now and hope we can figure this out soon or my wife will not be too happy. Is it possible that the vacuum lines that control the heater are not working? When I replaced my stereo 3 years ago I remember that all the controls were vacuum lines. However I am not sure where they get the vacuum from. When I change the settings it seems to make the same noise as always. it sometimes will start heating then quit after a while or when you turn off the car then turn it back on. Is this also something new to Ford's Taurus or maybe I find it strange that so many people have the same problem but I have not seen the answer online anwhere yet. I have solved a few problems online and hope this one is the same. Good luck and I will keep hunting for an answer. I will check back to see if we can figure this out.

• No heat can also be caused by blown engine head gaskets. This messes with coolant flow through the system, preventing enough coolant from flowing through the heater core. But if one or both of your head gaskets are blown, your car will have other symptoms, such as smoke coming from the tailpipe (oil mixing with the water), overheating, etc.

• There's a door under the dash that directs air over the heater core. If it is broken then you will not get heat but you will still have A/C. To fix it you will have to take the dash apart.

• Check heater blower fuse and blower motor; coolant level; heater hose from radiator to heater core, and from heater core to water pump, for water shutoff both hoses should get warm with engine running and temp selector on hot.

• I have a 2001 Ford Taurus and have the same problem. When I consulted a Ford dealership they ask me if the coolant was brown and yes indeed the water looked more like mud water than the usual green anti-freeze. They told me that it is very common for the Taurus heater core to get blocked and that was more than likely what was going on. I flushed the system with no results because the heater core involves removing the dash to access, and the dealer book shows that job in the 6 hour range. I'm going to try all other options before I replace the heater core but that might be the only solution, besides winter is coming soon.

• Taurus heater cores are well-known for clogging - especially if something along the lines of "stop-leak" was ever poured in the radiator, or the radiator has not been serviced regularly.

• One solution is to flush the heater core - this can be done by disconnecting the heater core hoses at the firewall and simply flushing it with a garden hose and nozzle. However, you should also do a more complete flush, which would include the engine too, since there may be rust in its coolant passages too, which may re-clog the heater core if you don't clean it out. Otherwise take it to a shop and have this done.

• Your heater core is probably clogged. To fix this remove both hoses that go to the heater core, they would look similar to radiator hoses, but smaller diameter. Then run water through both ways until the water runs through clean. That may fix your problem.

• If there is no air at all blowing, then check the fuse for the heating. If the fuse is good, replace the blower motor. If there is air, just no heat, replace the heater core. You will find the core on the passenger side of the dash panel.

• Either there is a vacuum leak going to the Heater Control Valve, or the heater core is blocked, or heater hoses blocked, or NO thermostat or it's stuck open. OR the mixer/blend door actuator is bad or disconnected.
• The cooling system is pretty straightforward in how it works, so it is possible that the 'wire' that links the 'temperature-control' on the dash board to the 'interior heater unit' broke or became disconnected (at one end or the other) while last being in the 'Cold' position. Does the 'temperature control' knob or handle for the temperature seem easier to move than previously? That may be an indication of that situation just described. This isn't usually a quick fix item as, unless you can locate both ends of the controlling wire, you'll have to get into the dashboard or floor board to fix it. The floor board may be your starting spot as it may be more accessible. Second thought is that your internal heater has become plugged up significantly. That could have to be due to adding over-the-counter 'STOP-LEAK' type chemicals to the cooling system, but this is a somewhat 'remote' probability. However, if you haven't done a coolant flush since the car was built in 1999, there could be rust and other build up within the coolant system to certainly at least restrict the flow of coolant to the heater. However, if you haven't noticed a gradual loss of heating over the years, my bet is on the control linkage I spoke of. Good Luck.

• The thermostat may be stuck and need replacing. Also, this is pretty rare, but if the car is older, and the coolant has not been changed per specs, sometimes the vanes in the water pump may corrode and fall off. That causes a reduced coolant flow and can get expensive real quick Replacing the water pump is something the do-it-yourselfer can usually do, unless you want to keep a dealer service dept happy. But replacing the water pump is probably the last thing to try, though even if it appears unnecessary, it may be worth it in the long run if the water pump has 100,000 or more miles on it, since it will need to be replaced soon anyway.

• We own a 1997 Taurus GL Sedan and have had our own issues with the heater. Based on that, here is what you are most likely looking at: a clogged heater core. The good news is that you might get lucky and have it cured by doing an acid flush of the cooling system. The bad news is you may have to have the heater core replaced. That is an expensive fix as most of the cost is in labor to having to disassemble the dash and firewall to get to the core itself.

• If you know any mechanics, you are in luck. Hopefully one whose life you saved and he owes you big time. I don't know if I would call this a do-it-yourself job, it may depend on your skill level under the hood. I bit the bullet and had my local dealer do the core swap for me. Final damage: $2160.86

• I am also trying to solve no heat issue in 99 Sable. New water pump, thermostat, heater core, replaced corroded steel lines leading to core. No heat still. Just wanted to let you all know, the heater core job can be done in 2 hours or less if you check out on Google video, search heater core shortcut. The vehicle shown is a Taurus, but twin of the Sable. I actually did as he shows in video and it sure was easier than the water pump job. I did find that to pull the core it helps to push the inlet pipes from inside the engine compartment to pop the seal on the rubber grommets holding them in place, then allowing you to actually pull on the no longer recessed core from the inside of the car.

Other Ideas & a water pump culprit:

It could be a lot really. Heater core stopped up?

Have you checked the thermostat?

If your Taurus - Sable has 150,000 or more miles on it, you may need a water pump. They wear out. They have fins on them and I have a 2000 Taurus and was what was wrong with mine. The water pump kind of self-destructs on the inside without leaking out the weep hole. The fins just fall apart and you lose heat for your heater and the engine will overheat too.

Please refer to the related questions for more information.

Answer 2

The most likely problem is due to lack of radiator fluid. Very easy to check the level in the storage tank. I know because it happened to me. Why the fluid disappeared is still a mystery. The same problem has occurred in two Taurus wagons I've owned, 1996 and 2000 years. It is amazing how my wife did not notice, and the engine did not overheat and seize.

Answer 3

Well it can be anything from having a small air pocket in your coolant system or something more involved as a bad heater core. There are quite a few different reason a car may not be blowing hot air with the heater on. Best thing you can do is take it to a shop and let them diagnose it. Sure anyone can run down a list of reasons it could be happening but at the end of the day, if you have to ask why a car isnt blowing hot air, you more than likely dont have the know how, skills, or tools to diagnose the problem. Not meant to be and insult. Just meant to be the truth. So the best thing you can do is take it to a shop.

But if you insist on knowing some causes heres a few:

Air trapped in your coolant system.

Thermostat not opening to allow coolant to circulate properly

Thermostat stuck closed not allowing coolant to circulate

Bad water pump

Not enough coolant in the system

Clogged radiator/coolant system

Bad heater core

Climate control switches are malfunctioning

bad inlet and outlet radiator hoses

The problems can range from something simple to something much more inolved

Answer 4

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Answer 5

it could be that you have a leak in an zircon hose and so the system has no gas. In this case it would be a new hose and a full top up of air con gas.

Answer 6

restricted flow,water pump starting to fail,thermostat is stuck or not opening fully,heater core is restricted,in or out lines to the heater core could have a blockage...