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Is it the heater core or blend door

I have a 98 Ford Taurus SE stationwagon. Now with winter upon us I have found my heater does not work up to full heating. If I turn the heat on as soon as I start the car I get nothing but cold air. Once the car has reached it’s normal wamred up temp, I will then turn on the heat. Luke warm air will come out. If I turn the temp gauge over to cold, the air most definitly will get cold. When I turn it back to warm it warms up, just not real warm but I do hear sound from the dash which I believe is the blend door moving.

So, is my blend door just not going all the way and giving me a mix or warm and cold? Or could the heater core need to be drained? Since I am getting “warmer” air when I switch over from the cold to warm setting wouldn’t that mean the blend door is not closing completely?

Also, if I was to have the heater core drained, is that hard to do and what is a fair price to have done?

" If I turn the heat on as soon as I start the car I get nothing but cold air"

Ummm…How could you expect to get heat from a cold engine?

That detail aside, the first thing that I would do is to have the cooling system “burped” to purge it of possible trapped air. If you have some air trapped in the heater core, that would explain a low level of heat from a warmed up engine. If that low-cost fix does not improve things, then you can go to the much more expensive route of tearing into things to see which of the blend doors might be stuck.

Well in my former 2005 Malibu, I could crank up my car and within a minute or so have hot air coming out, so maybe I am spoiled. How do you burp it? If it is the blend doors I will just survive with “luke warm” air as I have been told that it is very expensive to work on those.

The cost of changing heater cores and blend doors/blend door motors can be very model-specific. Some of them are very difficult to get to, others are not. Either could be your problem.

You need to check the temp of the heater hoses. Can you get your hands on an infrared thermometer? If not, try taping an instant-read thermometer to the heater hoses or feel with your hands.

Warm up the engine fully and turn the blower to high and set to full heat. Check the radiator hoses. If the flow through the heater core is good, there should not be much or any temperature difference between the heater core inlet and outlet hoses. If there is, unhook and flush the heater core with a garden hose. If you are doing this yourself, be very gentle with when removing the hoses from the heater core lest you damage the core. It may not be easy. If the hoses are accessible at both ends, just cut them off and replace them if they are not expensive.

If the heater core passes, try to find out where the blend door motor and door are and if you can see them. YOu might be able to tell by watching if they are going full travel. I would try to find a Taurus board for that info.

“The cost of changing heater cores and blend doors/blend door motors can be very model-specific. Some of them are very difficult to get to, others are not.”

If the '98 Taurus is like the '86 Taurus that I had, the heater core is VERY difficult to access, necessitating removal of the dashboard. IIRC, I paid something on the order of $700 for this job back in 1991. With inflation, I would hate to think what that job would cost 18 or 19 years later.

A sticking thermostat is also a good possibility.

I remember my ol’ '79 Toyota taking forever to warm up…and then only luke warm…until I changed the 'stat.

There is a video on YouTube that shows how to access, diagnose, and repair the Taurus. You need to make sure that the heater core is clear and operating correctly. A stopped up core is common on the Taurus/Sable due to the OEM antifreeze used in the system. Regardless of other actions, a good flush of the system is always a good idea. Any of the oil change franchises can perform this service. The best way to check the temperature manually is to check both heater hoses from a cold start and verify that they warm up at about the same rate and get uncomfortably hot.

There are reported problems with the blend door and actuator motor on this model and you can find more information in the video.

I think this is the third Taurusable heat issue posted this evening. Cgallen’s youtube suggestion (above) is a good one. I just looked at it after reading his post to one of the earlier questions. There is also a video on how to change the heater core in an hour and a half. (WOW!)

That said, I’ve never had to replace a Taurusable heater core. I’ve had good luck with flushing them out with a 50-50 solution of CLR. You don’t have to remove the heater hoses at the core itself where they go thru the firewall. You can separate them, in and out, probably a foot away from the core. It makes it much easier to flush with a hose or to give the core a CLR treatment.

This is something I occasionally experience at home. I believe this is just few and the same with some heater or blend half door… Sometimes I felt like it’s sticky, the one with ionizer? Do you have that? Well that’s the case for me… Right now, Im making sure I use it at a considerable time interval to avoid overheating or something…