No heat

[Dr.Manhattan]

I feel this is actually a fairly general car question, but to be specific my question is actually in regards to a 2001 Ford Taurus Flex Fuel car. I know this is Explorerforum, but I get some great answers here, and after getting one useless reply on Fordtaurus.net out of 150+ views I figured I'd try my luck here.

In a nut shell, I tried burping the system by running the engine with the cap off and the heat blasting on full (cold air coming out in this case). The temperature gauge wouldn't even climb unless I drove the car around. (I notice overall that even driving around for a half hour to get to my job, the gauge scarcely climbs). This process failed. I checked the blend door and actuator which are both in working order. I felt the rubber hoses for the heater core and they felt somewhat warm. I could only bear to touch the metal parts with one fingertip and I can gather they were hot, but I was afraid to really touch down on it.

I've replaced the stat a number of times and am contemplating flushing the system if I can get my hands on a Flush T. Unfortunately Pep Boys does not carry this. I'd love to know where to get one.

Anyway, if anyone can help me get heat working in this car it'd be great. The air goes from freezing to not as cold at best and I have a 2 month old kid that gets driven around in that car.

 

[swetrid]

Heater cores always go bad on taurus, you can try taking the hose off the heater core and try backflushing it. That usually works for awhile until it gets plugged up again.

 

[Dr.Manhattan]

so even though the hoses feel somewhat hot it's the heater core? I do indeed intend to flush the core as I can't think of any other issues. Is there anything besides the blend door/actuator and heater core that effect heat?

To flush the heater core I need to stop flow to the bi pass hose. How do I do that?

 

[OneLever]

I've replaced the stat a number of times

Why?

The temperature gauge wouldn't even climb unless I drove the car around. (I notice overall that even driving around for a half hour to get to my job, the gauge scarcely climbs)...

The temperature gauge shows engine coolant temperature. Even if the HVAC heat isn't working that should still climb to normal within 10 minutes of idling in the cold. When all else fails check the obvious: Are you sure you've been putting the correct temperature thermostat on there? A sufficiently low opening temperature thermostat would cause your problems.

I felt the rubber hoses for the heater core and they felt somewhat warm.

The upper and lower radiator hoses, and both heater core hoses should all be hot enough that you can hold them but only for a few seconds before it becomes too much. If your engine coolant isn't getting up to temperature though, as stated above, then the hoses wouldn't get very hot.


Edit:

Is there anything besides the blend door/actuator and heater core that effect heat?

Yes. The blower motor which is what pushes air across the heater core. Should be easy to tell if it's working because you can hear it blowing air as you change the fan speed.

 

[Dr.Manhattan]

The first time I replaced the stat was because it was no longer good. The second time, I purchased a 180 degree stat from autozone and for some reason my knowitall girlfriend and her grandmother had to go poking around (she's the primary driver of the car while I have my Explorer). They pulled it out and I never got to see it while she drove around without a stat. This was in the summer mind you. I was told it had all sorts of gunk around it, but because I didn't get to see it, it could have been gasket silicone for all I know.

While in Autozone recently, I got one of those aftermarket performance ones. Can't remember the temperature range. Might have been 160. What did you mean by a sufficiently low stat? Should I be putting in a 190? I also hear Ford's don't do very well with aftermarket stats.

As far as the blower motor, well that's a no brainer. Works fine.

 

[OneLever]

The first time I replaced the stat was because it was no longer good.

What led you to believe this? I'm tracking down possible prior problems.

...girlfriend and her grandmother ...They pulled it out and I never got to see it while she drove around without a stat. This was in the summer mind you.

That is one of the most bizarre symptoms I have ever read on this forum.

What did you mean by a sufficiently low stat? Should I be putting in a 190?

The thermostat is, as you know, a temperature controlled valve. It is normally closed and keeps coolant circulating inside the engine when it first starts. This allows the engine to build up heat to get to operating temperature quickly. When the opening temperature of the thermostat is reached it opens and allows coolant to flow through the radiator. This removes heat from the coolant, and the rate at which heat is removed is determined by fan speed.

If the thermostat has an artificially low opening temperature it will open sooner than it used to. This will cause coolant to circulate through the radiator and loose heat before the engine has been brought to operating temperature. Which means the engine will take a much longer time to reach that temperature. Coincidentally, since coolant is circulated through the heater core to provide HVAC heat this means that you will have no heat.

I'm not saying the thermostat you put in was positively too low. If I were you I'd go to a dealership and buy just the thermostat from them based off your VIN. That way you avoid aftermarket woes and you'll know what the stock temperature was. I have heard of some aftermarket thermostats being of poor quality. The brand I heard good reviews on and have used personally because of them is Stant.

If you put in a thermostat that is rated to open at a temperature higher than stock you could very well blow a head gasket from overheating. So don't take my word for it. You need to find out what the stock temperature was.

 

[Dr.Manhattan]

Ok... what led me to believe this. I actually took someone else's word for it as they sat there and pushed the button inward (which seems like new ones do the same). The car actually was overheating and I replaced the water pump. We've also had the radiator boiled and the timing chain cover needed a new gasket. I've been through the ringer with this cooling system. Might I add that we had rusty colored coolant.

I replaced the stat today and indeed the temperature gauge jumped way quicker. However I still have no heat whatsoever. My next move is to drain the coolant, put in a flush in hopes that it loosens stuff up and then use my flush t on the heater core when it comes in the mail.

 

[OneLever]

Ok... what led me to believe this. I actually took someone else's word for it as they sat there and pushed the button inward (which seems like new ones do the same).

I do not understand what these words mean.

The car actually was overheating

Well a clogged coolant system would prevent you from getting heat to the heater core. I'm surprised that didn't lead to a head gasket failure though. Did the dash temperature gauge show overheating? How was this determined.

I replaced the stat today and indeed the temperature gauge jumped way quicker.

What temperature thermostat did you put in? What is the stock thermostat temperature?

 

[Dr.Manhattan]

What I was saying is, there is the little cylinder that pushes open and closed on the stat. Someone told me that if you can push it it's no good. I kept urging to boil it in a pot, but they threw it away.

I just installed a stock on Sunday. 192 degrees. Operating temperature is now reached in an adequate amount of time, but still no heat.

And actually the heater core can be clogged and the system otherwise be fine as the car has a heater core bipass line.

 

[Dr.Manhattan]

I just received a flush t in the mail and it is telling me to hook up to the heater inlet. Would that be the line that runs from the Water pump to the heater core? These transverse engines are obnoxious. Not like my 94 ex. So much easier.

 

[OneLever]

Well at least you're making progress. That's one issue solved (coolant temperature). Did you test the new thermostat for opening in a pot of boiling water before installing it? Never hurts to make sure although it's not worth pulling it out to check if you didn't.

I honestly don't know which heater hose the inlet would be. If I had to guess I would say the one from the water pump.

 

[Dr.Manhattan]

Yeah that is the hose I am thinking too. I installed it in the parking lot of Autozone in the rain no less. It must be working due to the noticeable change. No way I had access to boiling water there.