I have a 2001 F150. My heat doesn't work at all but my air conditioner works fine. I really don't want to have to replace the heater core because of all the labor with the dashboard and all that unless I absolutely have to so what are some other things to do first? Is the only option to flush out the hoses or could it be from something else?

 

coolant level ok?

 

Explain "doesn't work at all", please?

 

Coolant level is fine and by doesn't work I mean air blows out but it never gets warm, even after an hour of driving.

 

I had the same issue and this heater control valve was stuck closed.

http://www.rockauto.com/catalog/more...888&cc=1434764

 

The F150 doesn't have such a valve.

It's probably either bad thermostat, air bubble in the system, a worn out water pump, a clogged heater core (check both hoses to see if they are both hot or not), a stripped temperature control ****, a bad blend door actuator, or a busted/stuck blend door.

This ain't rocket science to pin point.

 

Ok so I am having problems with getting good heat out of my 99. I have felt both heater core hoses inside the engine bay after running for 30+ mins and they are both luke warm at best. I was planning on replacing the heater core but want to confirm before digging in.

 

Your problem is under the hood, not in the dash.

Check coolant level, thermostat operation, water pump, in that order.

Like I said, this ain't rocket science.

 

OK I'll do this. It's for my brothers truck. He recently had I want to say the head gaskets [both] replaced (It was leaking/burning oil on the passenger side, had them do both) and the mechanic who replaced them said the heater core was plugged. Tried flushing it multiple times. I tried purging air bubbles last time I was up by letting it run without the rad cap on for 15-20 mins. When the gaskets were done, they replaced the radiator at the same time too.

Which makes me think that they should've replaced or at least checked the thermostat. The way to check that is after the truck is running feeling the upper and lower hoses going into the radiator correct? Both should be hot is my understanding.

Lastly, from what I can read about the water pump and heat, is that if it's going out (impeller fins worn) that the heat will be good when you're working the engine into higher rpms. This isn't the case with his truck, it blows luke warm always. And as mentioned before, the heater core hoses from the engine bay are also luke warm after a considerable amount of time warming up.

 

AUGHHH! I am having the same problem with my '02 F150 4.6 L and had hoped to find some info here but the more recent threads related to this problem are all dead ends. I will add that the selector **** for the heat/air is difficult to turn in addition to the lack of heated air. (Also a friend told me the AC compressor sounds as if it's running even in heat mode? Don't know if that's so but is it a symptom of anything?) Coolant odor through vents when heat first turned on but gradually dissipates after a little while. Coolant level below minimum cold level when problem first appeared. Haven't been driving the truck lately due to ridiculously cold weather & snow/ice, so haven't checked since adding coolant/water mix to expansion tank...

 

As an update for you Redeckkhikkchik, we replaced the thermostat with an OEM Motorcraft one, which the one we pulled out was the exact same. So the new parts list goes such as this:
- Motorcraft OEM thermostat
- New heater core
- New, updated blend door

Among the repairs he had done that we didn't do:
- New head gaskets because of oil leak on passenger side
- New OEM radiator

We've attemped purging the air out by letting it run slightly on an incline with the rad cap open. As of late when asking my brother (who owns the truck), he said that sometimes the heat is great after running for a bit, but for the most part it's luke warm. It seems sporadic and am out of ideas other than waterpump as to what could be causing this.

 

If it's not fixed by now, here's a few ideas.

When you (or he) had the heater core replaced did anyone check the temperature control ***, and make sure the blend door actuator like SHO89 mentioned? If you haven't done so already pull straight out on the temperature control *** look to see if there is a crack on the underneath side, that's the culprit. I have taken a file and made a small groove around it, rap a small piece of wire ( stainless is better) and twist. If there's a dealer close just buy one. The actuator can be removed and tested by turning the temperature control *** to see if the actuator moves. Apply a little pressure to the shaft as to put a little load on it. If it moves good it's not that either. There's one more thing, in one of the heater hoses there's an orifice to make a pressure drop across the heater core. For good info [URL="www.heatertreater.net/"]
Good luck, let us know what worked so this won't be one of those dead end threads.

 

I'll give that a try once we get to it. My brother lives 4 hours away and basically has conceded until spring when it's warmer out. We changed the heater core and checked the actuator once everything was back together. I didn't think about maybe applying 12v when it was taken apart, but what do you do. When you turn the **** to cold, it goes cold. When you turn it back to heat, it gets warmer, just not as much as it should. The blend door wasn't broken but we replaced it with a Dorman unit that had a aluminum sleeve on the shaft to supposedly strength the piece.

I'm not sure what you mean with the wire? Are you doing this to the shaft that the **** sits on to turn it by hand? A little more explanation if you wouldn't mind.

Heater hose does have an orifice in it and it was there before and still is there now. I believe that was in the hose that we couldn't remove because it was all the way in the back of the engine by the firewall. Couldn't get that spring clamp off to take the hose completely off. It was too far back there. There may be some merit in that being blocked but as of now we don't have a way to get it off to clean it.
My brother said that it gets nice and warm (not as hot as it should) but warmer than average on very rare occasions so I would think that rules out the orifice blockage as that should have consistently low flow.

Finally, how do you actually get that blend door actuator out? It looks like it's riding on the floorboard of the truck. I couldn't figure out quickly how to take it out. If you have a DIY available that would be great. Like I said, I didn't think to check it when everything was apart, because you couldn't just turn the ignition on and turn hvac on. I think I would have had to apply 12V of power to it and it didn't come to mind when doing the repair.

We have followed SHO's steps up until the water pump. Bought a brand new thermostat and assumed it was good. Didn't do the little flame test or whatever test is supposed to be done to the thermostat. Coolant level was fine. Haven't touched water pump yet. Truck has only aobut 112k if I remember right. I've heard these last quite some time in the 5.4 Fords.

I appreciate the ideas and will try and update whenever we do something more.

Also one last thing. The temp inside that cab seems to somewhat relate to the temp outside the truck. If it's warmer out outside, inside is warmer too according to my brother.

 

As for the ***, on the underneath side of the *** where the shaft goes in, you use a triangle file ( if it is cracked ) and file a notch in the plastic just enough so the small wire won't fall off, twist the wire as to tighten so the shaft can't move inside the ***. Or just buy one at a dealer some auto parts stores may sale them

http://www.heatertreater.net/magento...150-97-04.html this is a url to a site where you can watch a video on replacing a blend door, it shows how to remove the blend door actuator and turn the key switch on and move it to cold and hot to see if the actuator move while putting a little pressure on the actuator shaft. Good Luck

Turtle

 

Well, it had better be. Otherwise, the air conditioner is on....