Hi,

I hope someone here can help me.

I am having problems with my heater. Sometimes I get a little heat, and other times I get only cold air.

I have read probably a hundred posts on the subject, both here and elswhere. I have joined eAutoRepair. com, as well as bought the Ford service manual on a CD, and I am stuck.

Here is what I know:
I have a new thermostat and new coolant, and have backflushed the heater core. There wasn't anything in there... no sludge.
The heater hose going from the pump to firewall (on the left) is hot, and the heater hose going from the firewall to the block (on the right) is also very hot. They are both almost too hot to handle after idling for 10 minutes.
I took out the center panel so I could watch the blend-door actuator, and it rotates fine, without a hitch, and moves the arm up and down.
Just to be sure, I removed the acuator and manipulated the arm/lever by hand, and it moves very smoothly. I can hear something that sounds like a door or panel moving and closing with a bit of a "thunck." Very quite, but I can hear/feel it.
When I turn the temperature dial, the volume of air decreases when I turn from "cold" to "hot." It is the same when I removed the actuator and moved the arm up and down by hand.
The volume of air is quite strong when in the "cold" position, and drops, sometimes a little, sometimes a lot, and sometimes to almost nothing, when I move it to the "hot" position. The fan is still turning just as strongly, but it sounds as though something is obstructing the air flow.
Like I said, sometimes I get a little heat, and sometimes I get cold air.I don't know where to go next. The diagnostics in both eAutoRepair and the Ford manual seem to stop there, and say replace the temperature blend door, but I can't see where it is, and neither resource shows me. Neither does my Chilton Manual. The door sounds like it's working to me, but I can't see it to know for sure.

What do I do now? How do I get to the blend door? Does it sound like it may be something else entirely?

If the heater core where bad, would the hoses be hot going in and out?

I'm stuck. If anyone can help me diagnose this, I would appreciate it.

Thank you,

Marc

Do you have Electronic Automatic Temperature Control System or manual?

Even if the blend door actuator is working the blend door could be broken. I have seen a broken blend door on a 99 Marquis and a 2000 f150. Not sure if your taurus is the same design. The pivot on the opposite side of the actuator went bad. It's a real pain to replace. The instrument panel might need to be removed?? The Marq did.

Have you checked the pollen air filter (if you have one). It's located under the Cowl vent screen on the passenger side. Maybe it's plugged.

Water pump blades can wear down to just enough to circulate water but not sufficent circulation for the heater. Replace the water pump.

Hi,

Thanks for the input. I really appreciate it.

This is what I did.

I replaced the air cabin filter -- it was totally clogged, with dirt and leaves, etc.

Also, when I took off the cowling thing to get to the cabin air filter, I realized that I wasn't as smart as I thought I was.

I'm sure many of you knew this, but I didn't. The hose from the water pump runs into a "T," and so does the return hose. These "T"s go to the heater hoses AND another hose that I have since found out is a bypass hose. Those hoses were hot to the touch, but the heater hoses (which I couldn't see with the cowling thing on) were cold! Aha!

So I backflushed the heater core again, but this time I pinched off that bypass hose.

In swear that rust came out of the heater core for over a half hour. I kept turning the hose on and off, which brought more rust out. I was shocked.

I buttoned the whole thing up, and lo and behold... heat!

I think I will run the heater once a week or so, even in the summer, to keep coolant circulating in the heater core, so it won't get clogged again. I think that is the problem... long periods where nothing circulates in the core, and it sits and rusts.

I hope my ignorance, and what I learned, will help out others with the same problem.

Marc

Its going to stop working again, rust is coming from the engine . . . . put in a filter! rust junk floats in antifreeze which will plug the core again. Also reverse the in/out core hoses. See my prior post!

"I think I will run the heater once a week or so, even in the summer,"
You should always do that, and run the AC in the winter to. You've got rust pockets settled in the low spots of your engine so go to the auto parts store and get some of that cooling system cleanser and you should find a few different kinds. Take the t'stat out and follow the directions and make sure you wear protective glasses or goggles because the clean is highly caustic and can cause severe burns to eyes and skin. You want to drive as long as the directions say with the heater on wide open and get the coolant hot & churned up then do a complete flush and get every last drop of the flushing agent out taking the rust with it. Some have a neutralizer so put that in and drive it according to directions then flush it again. Now it should be relatively rust free ready for fresh anti freeze 50-50 mixture never exceeding 50% anti freeze.:nono: Not a good idea to put cold water in a hot engine so let it cool down awhile lest you crack the block or heads.

They have shops with coolant flushers and I don't know how much they charge and some radiator shops will do you a flush without taking the radiator off. Make darn sure you have a knowedgable technician because to much pressure can blow up your heater core. :uhoh: http://www.redwoodgeneral.com/cooling_systems.htm

"Also reverse the in/out core hoses. See my prior post!"
I have a 03 Vulcan and please tell me how to reverse the heater core hoses.
Reversing the flow seems like a good idea to keep acumilated crud churned up.

not sure about your engine, but to reverse just find the IN and the OUT hose at the core on the fire wall pull them off and switch them. Why spend the time, work and money on a pro flush which will never clear all the junk perminitly.. . . you need to install a filter $12 its a perminit fix, forget the flush stuff, see my prior post

not sure about your engine, but to reverse just find the IN and the OUT hose at the core on the fire wall pull them off and switch them. Why spend the time, work and money on a pro flush which will never clear all the junk perminitly.. . . you need to install a filter $12 its a perminit fix, forget the flush stuff, see my prior post

I totally agree and is exactly what I did. I also blocked off the bypass hose. The only reason I can think of for the bypass hose is that Ford knew that a plugged heater core could make the engine overheat. When my filter plugged up the engine began to run hot. New filter, problem solved. So if you run a filter, watch your engine temps.

I have a question: If the cooling system is properly maintained, drained and flushed and put in new anti-freeze every three years, then how do you get rust in a cooling system? I drained and flushed my 03 in about an hour and it sure is a whole lot easier to do that than go through all the aggrivation with rusty systems and plugged up heater cores. The filter sounds nice, but why would you need to do that if you properly maintain the cooling system?

OK, so you're not mechanically inclined. Then take it to the Ford dealer and pay them $75. and let them flush it and put in new anti freeze because it is a whole lot less hassel and WAY younder less expensive than messing with plugged heater cores. Preventive Maintenance 101: You take care of it and it will take care of you. Pay me some now or a lot later.

Without going into detail, I KNOW the cooling system is the most overlooked component in the average motor vehicle, and it is one of the most important. Just like regular oil changes, it contributes greatly to trouble free vehicle, but instead of following the maintenance manual people will wait until they have trouble with the cooling system THEN wonder why. "An ounce of prevention is worth a pound of cure."

Truckers engines run 500K miles and never rust, but they get them serviced because they make their living with them. Tug boats we drained and flushed every two years and the engines run 15,000 hours and never rusted. You want rust then use plain water. Anti-freeze contains rust preventitive package so IF you mix it say 40% anti freze and 60% CLEAN water you're good to go. But it's the same as engine oil and you must drain and change it or eventually you will have a problem.

Me, I spend the six bucks for a fresh gal of anti freeze and spend an hour change my coolant every two years. I'm 66 and owned a lot of vehicles, boats and tractors in my day and I have NEVER had a rusty cooling system on any of them. BUT I maintained the cooling system properly. If you READ and FOLLOW the recommended maintenance schedule it IS a piece of cake and without a doubt the cheapest way to go. :2cents:

The engine blocks were not cleaned good enough from the factory. You should never see sand in the coolant. That sand abrates the block and water pump impeller. Then the rust begins.

Normal flushing will not remove the build-up (sand ect) that occurs in the heater core. The heater core acts like a filter and plugs-up. The only way the remove it is to reverse the flow of collant and expel it from the system, something that most service techs don't do.

I have back-flushed my heater core 4 times, and get particles everytime. Now I just replace the filter. Much easier to do.

I understand, but ethylene glycol anti-freeze contains a rust inhibitor that coats the metal and prevents rusting otherwise the system would be spewing rust in a year or so and I totally agree, flushing and backflushing is a good thing.

This may surprise you, but there is a change that takes place with ethylene glycol and as it gets old and heats up and cools off hundreds of time it slowly decomposes and changes it's chemical composition and slowly turns into a corrosive compound. Say what? Yup, it turns into a sort of acid and loses it's rust inhibitor properties and starts eating away inside the cooling system hence you get R U S T in the cooling system. The situation then escalates because the rust particles retain heat and the rustier the coolant becomes the hotter your engine runs. The rust coats the metal surfaces preventing the coolant making proper contact to transfer the heat from the metal to the coolant.

I freely admit, I am from the old school and I belive discretion is the better part of valor. Some may claim their coolant is good for 5 years or 100K miles but for my money and time I will drain, flush and change my coolant and use 40% anti-freeze and 60% water every two years. :2cents:

I post this link not to sell or promote anything but to verify the info I have shared. Take time to read it and I believe you will learn a lot about anti freeze 'cause if you leave it in to long it becomes one of your engines worst enemies. http://www.neosyntheticoil.com/coolant.htm

"Remember that ethylene glycol is a toxic substance and dispose of it as required in your community. Not only is it toxic itself, but used ethylene glycol anti - freeze will undoubtedly contain toxic heavy metals."

Our country furnishes recycle centers to dispose of used motor oil, anti freeze and almost anything recycleable or toxic wastes.

I agree that regular changes are good but as we know most people dont do it until theres a problem of rust in the system so my answer, now that the damage is dune a filter will catch the rust. Anyway its how I solved my pluged heater after flushing 5-6 times didnt work . . . perminitly.

Cuda Jim: I pulled the cover off the passenger side vent and there IS a filter there and was it ever a awful disaster never chaged since new in 2003! That puppy had mold & mildew growing on it out the kazoo and completely clogged with dirt, leaves and gosh knows what else. I got a ultra fine house a/c filter at walmart and cut it to size and stuffed it in and sure does smell better. Thanks a lot and I was told that before but never took the time to look.

I remember asking the Ford service writer about it and she said if it didn't make reference to it in the owners manual it didn't have one. I looked and doesn't say a thing about a cabin filter, so she's not up to speed. Now, why doesn't that surprise me ? ? ? ? ?

I got a ultra fine house a/c filter at walmart and cut it to size and stuffed it in and sure does smell better.

Good idea, I bought 1 from Autozone, it was 15$ IIRC. It didn't seem to fit all that well and had to be crushed to get it in the opening.

IThis may surprise you, but there is a change that takes place with ethylene glycol and as it gets old and heats up and cools off hundreds of time it slowly decomposes and changes it's chemical composition and slowly turns into a corrosive compound. Say what? Yup, it turns into a sort of acid and loses it's rust inhibitor properties and starts eating away inside the cooling system hence you get R U S T in the cooling system.

I have my own theory about rust formation in the cooling systems. Rust is caused by oxidation, no oxygen, no rust. The only oxygen in the cooling system comes from water (h2o) so 18 years ago I filled the cooling system of our yard truck with 100% AF after replacing the radiator and freeze plugs in the block. It's still as green as the day it was put in. I partially drain the cooling system every year or so to get a look in the radiator, guess what I find....no scale or rust. I don't recommend this but how can argue with success. BTW: This yard truck gets used or should I say abused, everyday. Heck 1 time it was left running over a long weekend and didn't over heat in 80-90F temps. Flame suit on and ready!

Hate to be a nay-sayer but in order to work properly anti-freeze must be mixed with water and it's appearance can be very deceiving. Anti freeze is a pretty complicated thing and this link explains it well. http://www.phmeters.com/New_Folder/antifreeze_application_note.htm

"To combat corrosion, one must monitor the rate of corrosion within the cooling system. The rate is caused by a number of factors, including the acidity or alkalinity of the coolant. The acidity and alkalinity is measured on a pH scale and is very important. If the coolant remains alkaline, corrosion is inhibited but if it becomes acidic, the coolant begins to eat away at the interior of the system."

We have a pool and pH test strips and tomorrow I'll dip one in my coolant and check the pH and let you know what it is..

I did say it was an experiment, OK maybe it is not an experiment, I really don't care what happens to the yard truck. Heck it hasn't had an oil change in 3 years, just keep adding it as it leaks/burns out. I don't recommend doing this to any vehicle. You got my curiosity up so I tested my 18 year old AF and guess what, The PH is 10. hmmm.

I found this interesting. Same article in your link:
"The alkalinity of an antifreeze/water mix varies because of the additives used and the ingredient ratio but should be between the pH range of 8 and 11. The average antifreeze pH value is 10.5. When the antifreeze is mixed with water and added to the cooling system, the pH decreases to 8.5 to 9. A higher pH level is not always better because some new long-lasting coolants have a pH of 8.3. As long as the pH value stays stable, the cooling system is fine".

i have a 2000 ford taurus with all the same problems i have no heat changed therm, water pump had no fins, flushed everything. so i took it to a shop they said blown head gasket but did no compression test. said that was what caused the engine miss and no heat. i do not believe him. i been around cars all my life i have never seen a headgasket blow and have no symptoms like smoking, engine oil in coolant, coolant in engine oil, outside leak on head gasket, overheating, my taurus has none of these problems just no heat and engine miss

Welcome to the forum!

Have you had the codes read for the engine miss? Most auto parts stores will read your diagnostic codes at no charge, and if there is a bad enough misfire, it will set a code in the form of P030x where x is the cylinder number that the misfire has been detected on. If that narrows down to a single misfire, then you can inspect components related to that cylinder such as compression, spark plug, plug wire, fuel injector, etc. If the spark plug is abnormally clean or slightly green on that cylinder, then you might suspect coolant in that cylinder. If you find something else such as a bad plug wire and fix the misfire, then you can focus on the head issue with reasonable assurance the problem is not a head gasket.

If you do not have a diagnostic code for a misfire, then you may want to find a scan tool that can read the component parameters and check the individual cylinder misfire counts. In the component parameters, you can display cylinder misfires, even if the counts were not high enough yet to trip the Check Engine Light (CEL).

There have been NUMEROUS threads related to lack of heat, so I'm not going to address those here.

-Rod