99 Windstar, different no heat problem...

[superdutydave]

I searched for my particular symptom but didn't see it. Sorry if I missed it.

The heat will blow hot, but not consistently. I can switch between the different blends no problem, with the inconsistent heat blowing out each combo. Speed makes no difference.

The odd thing is the rear blows stone cold no matter what.

Any ideas?

[olopezm]

Hello Dave, welcome to the forum!

I believe you have a problem with your blend door actuator, it changes it's position to either provide hot or cold air to the interior, if it fails you will be stuck with either air being cold, hot or a mix of both.

Check here

Best regards,

Oscar.

[wiswind]

I would look at the front and rear heat issues as separate problems.
Front, it is possible but not at all likely to be a issue with a clogged heater core.
This is because the coolant ALWAYS flows through the heater core, regardless of your temperature setting.
This prevents stuff from settling out in there during the warm times of the year.

Blend door issue is very common.
Maybe the linkage between the electric motor that drives it, and the door is broken.....letting the door move about at will with each bump you hit.

Rear heat......check to see if the heater line is HOT back there.
If it is, then you have a blend door issue back there as well.

[superdutydave]

Thanks for the replies guys!

I've seen that thread on the blend door but wasn't sure if I should look there first. I guess I will.

I hoped the rear wasn't going to be a separate problem but maybe it is. I'll find out the week after Christmas while I'm on vacation.

I'll be sure to come back and let everybody know what I find.

Hope everybody ate enough today. I know I did and I ain't done yet!

[superdutydave]

Okay well I definitely don't have the blend door/actuator issues. I pulled the actuator out and it moves nice and smooth lock to lock, even with slight resistance applied with my fingers. I was also able to stick a screwdriver into the blend door slot and can turn that lock to lock as well, and can hear it flipping back and forth. No broken hinges.

I topped off my coolant, maybe a 1/2 gal's worth. I seem to be getting a bit more heat out of the front but it doesn't seem to be as hot on full heat as it used to be. It also seems to cool down slightly at idle.

I'm guessing that it might be the heater core. The hose on the right (looking at the firewall from the front bumper) is hot hot, but the one on the left isn't nearly as hot. They should both be the same temp right?

I guess my next step is to yank those 2 hoses and try flushing it out. Do I need to completely drain the system or should I be okay without doing that?

As for the rear, I still have no heat at all. I'll worry about that after getting the front dealt with.

[olopezm]

How about taking a look to the thermostat. If it's not working properly you can also loose heat to the inside of the car. I might be wrong on this but the hoses can have different temperatures depending on the thermostat's action.

I would replace the thermostat since it's a cheap part that doesn't takes more than minutes to replace. It is located after the upper radiator hose.

Best regards,

Oscar.

[superdutydave]

Good point. Maybe I will toss one in since it's still the original. 211,000 miles.

[superdutydave]

Does anyone know for sure about the 2 core hose temps? Are they supposed to feel the same?

[mark_gober]

Originally Posted by superdutydave

Does anyone know for sure about the 2 core hose temps? Are they supposed to feel the same?

I would guess that they'd be roughly the same temp. Theoretically, the output should be slightly cooler since you've cooled it down with the cool inside cabin air, but to the uncalibrated hand, they'd be pretty close.

Mark

One being cool could indicate a clogged heater core. I've had success in other vehicle by disconnecting the hoses and reverse flushing it with very low pressure (20-30 lbs, air) or water hose.

[superdutydave]

Thanks for the reply Mark.

[serge_saati]

If your temp gauge's needle is static at ~45% of the way of the gauge when it heats up, it indicates a good working thermostat and it'll be useless to replace it.
It could be a clogged core like the others mention it, or an intermittent coolant leak that cause lack of coolant pressure thus heating. Especially if you loose a lot of coolant intermittently from manifold.
Or maybe your water pump is weak or it slips on the belt.