Not much heat

[Kabel69]

I recently acquired my 2005 Explorer from my dad with a heating issue. AC worked great during the summer but now that it is starting to get a little colder I need the heat. My dad said he had changed the thermostat (temp gauge is reading normal operating temps) and the blend door actuator. He told me that the mechanic he talked to said there was a louver or something that wasn't letting the hot air come through and that the dash would need to be pulled to fix the problem at a price of $800-$1000.

When turning the temp dial from hot to cold I can see and feel the lever on the glove box side rotating up and down and there is no clicking nose indicating the gears are stripped in the actuator. I can't hear the blend door moving either.

The heater core is not clogged as my dad had put a hose to the heater core lines and water moved through freely.

When driving I get some heat through the vents but if I turn it up past 2 on the fan control there is more cool air coming through than heat. As I'm driving the air gets a little hotter than when I am sitting at a light.

Since I get some heat but not a lot...could this be a blend door issue and it's not opening up all the way to let the heat come through? I'm at a loss trying to figure this out. Any help would be appreciated.

 

[corkey]

blend door for sure , you should hear it move or feel the temp change ,,,

 

[Kabel69]

I can feel a slight temp change and more so when I'm driving. I cant find a diagram or picture that shows me where the blend door is as I know there is a company called heatertreater that makes a metal replacement and gives instructions on where to cut the heater box in order to replace the door without pulling the dash. I was thinking of buying a little camera scope to run down the vents to see if I can see the blend door. If I can figure out where it is and where I can cut to manually move the door for short term to get me through the winter I would be a happy camper.

I can feel the lever on the glove box side which I've read is part of the blend door and it rotates but I don't know if the blend door has come loose from it's pivot point or what.

 

[Kabel69]

Update.

I bought a camera scope to feed through the front vents to see if I could see anything. The blend door does move when I switch from hot to cold...I get a little bit of temp change but not enough to heat the vehicle once the temps start dropping. Is there a door or anything else I could be missing that would keep me from getting hotter air through the vents?

 

[lincolnshibuya]

is this an automatic or manual climate control? when you change the mode to floor, vents, defrost, recirc does the air flow changes? which vent provides hot air?

 

[Kabel69]

is this an automatic or manual climate control? when you change the mode to floor, vents, defrost, recirc does the air flow changes? which vent provides hot air?

I assume it's manual. regular old turn knobs to change hot to cold and vent selection. No loss in air flow when changing from vent to floor to defrost. It doesn't have the option for outside/inside air. just max AC and then each of the vent selections. Attached is a picture like my controls.

 

[lincolnshibuya]

try checking the heater control valve on the engine bay, with the hood up check if the vacuum hose is connected to the valve and when you move your temp the arm of the valve should move too. if you are losing vacuum due to leaks then that valve will not open or close completely.

the purpose of that valve is to allow heated coolant to go through when heating is required and close the flow when cooling is needed

 

[Kabel69]

I took a look at the valve and it doesn't appear to be moving when I change from hot to cold....I'll check again when I have some daylight and can look at it while someone else changes the temp inside the cab. I did notice that only one hose going into the heater core was getting warm. My dad said he flushed the heater core with a garden hose and there weren't any clogs. I'll see if I can take a hose to it tomorrow and see if anything has changed. He did say that the heater worked for a couple days after he had the blend door actuator changed so maybe something snuck through and clogged the heater core.

 

[imp]

I took a look at the valve and it doesn't appear to be moving when I change from hot to cold....I'll check again when I have some daylight and can look at it while someone else changes the temp inside the cab. I did notice that only one hose going into the heater core was getting warm. My dad said he flushed the heater core with a garden hose and there weren't any clogs. I'll see if I can take a hose to it tomorrow and see if anything has changed. He did say that the heater worked for a couple days after he had the blend door actuator changed so maybe something snuck through and clogged the heater core.

If there is hose on either side, inlet and outlet, of the vacuum controlled valve, feel both sides of the valve with your fingertips; inlet (from manifold) should be hot, outlet side leading to the heater core should also be hot. If it isn't, the valve is not operating for some reason, either lack of vacuum, or a defective valve diaphragm. Another possibility is failure at the control on the dashboard, possible hose connection failure. imp

 

[gary ds]

It's my understanding that the vacuum valve is open fully; when there's no vacuum or it's disconnected from vacuum line. And it's closed fully when it gets vacuum. When heater controls are turned on; no vacuum is given to the valve and it should be open. As others have said; both inlet and outlet hoses should be hot; you should have flow. Since you said it's better (hotter) while driving (increased pressure and flow from water pump) and one hose is cold; I'd say your heater core is clogged or valve is clogged/stuck closed. Or your're low on coolant. I reverse flushed my heater core and valve by disconnecting the heater hose at the front of engine. On the v6, the vacuum valve is very accessable to clean or lube. Hope this helps. gary ds

 

[Kabel69]

It's my understanding that the vacuum valve is open fully; when there's no vacuum or it's disconnected from vacuum line. And it's closed fully when it gets vacuum. When heater controls are turned on; no vacuum is given to the valve and it should be open. As others have said; both inlet and outlet hoses should be hot; you should have flow. Since you said it's better (hotter) while driving (increased pressure and flow from water pump) and one hose is cold; I'd say your heater core is clogged or valve is clogged/stuck closed. Or your're low on coolant. I reverse flushed my heater core and valve by disconnecting the heater hose at the front of engine. On the v6, the vacuum valve is very accessable to clean or lube. Hope this helps. gary ds

Thanks, I plan on working on it today. I attempted to flush the heater core the other night by putting a couple clear plastic tubes on the heater core lines but the tube I got had quite a few kinks and flattened spots that I couldn't get good water pressure through. It seemed to help a tiny bit as the heat felt like it might have increased a little while driving. It also gets a little cooler when I come to a stop so I'm thinking I might have some air in the system or it's low on coolant and not pulling from the recovery tank.

I'm going to get some new tubing that has held it's shape and possibly change out the heater control valve to see if that fixes the problem. I'm also going to pull the recovery tank and drain it as I think there might be a blockage in there. Supposed to be nicer weather today and Sunday so it's a good time to try to figure this thing out.

 

[gary ds]

I clamped my outlet hose from the heater core directly to the nozzle of my house hose handle and tried to "pulse" flush, I was carefull not give it too much pressure. Mine blasted through and had a lot of flow and pressure. Remove the vacuum valve and look thru it. Should be open and clear. I've heard of people replacing the valve with a short piece of plumbing pipe temporarily. 3/8? Good 195* thermostat? gary ds

 

[Kabel69]

Ok, here is where I'm at. I flushed the heater core again and I get flow through it. I might try again as I don't believe I was getting as much flow out as I had going in. I also replaced the heater control valve with a new one since the old ones lever felt like it wasn't moving freely. $20 part so I wasn't too worried about it. My upper radiator hose and also the in hose to the heater core get hot but the hose coming out of the heater core doesn't feel very warm to me.

I plugged in my bluetooth diagnostic tool to monitor the coolant temp and I noticed once it got to 90 degrees C it would drop back down to 85 degrees C which is a range of 185-194 degrees. I thought the coolant should be a little hotter than that. When I am driving I can feel the air in the vents get a little warmer but when I come to a stop it definately cools down. I tried burping the system and driving it around thinking I might have air in the system and it doesn't seem to pull anything out of the recovery tank.

I pulled the bottom hose off the radiator coming from the recovery tank and it has good flow and the coolant coming out of the radiator was nice and green and not dirty. Anyone have any suggestions as to what to look at next?

 

[Kabel69]

Ok, here is where I'm at. I flushed the heater core again and I get flow through it. I might try again as I don't believe I was getting as much flow out as I had going in. I flushed it until all of the water coming out was clear. I also replaced the heater control valve with a new one since the old ones lever felt like it wasn't moving freely. $20 part so I wasn't too worried about it. My upper radiator hose and also the in hose to the heater core get hot but the hose coming out of the heater core doesn't feel very warm to me.

I plugged in my bluetooth diagnostic tool to monitor the coolant temp and I noticed once it got to 90 degrees C it would drop back down to 85 degrees C which is a range of 185-194 degrees. I thought the coolant should be a little hotter than that. When I am driving I can feel the air in the vents get a little warmer but when I come to a stop it definately cools down. I tried burping the system and driving it around thinking I might have air in the system and it doesn't seem to pull anything out of the recovery tank.

I pulled the bottom hose off the radiator coming from the recovery tank and it has good flow and the coolant coming out of the radiator was nice and green and not dirty. Anyone have any suggestions as to what to look at next?

Edit: It also seems like I have no pressure build up in the system. After driving around and getting the engine up to operating temps I can unscrew the recovery tank cap and there is still no hissing sound. I'm wondering if the water pump isn't pushing enough coolant through. The engine never overheats and sits a hair under the halfway mark.

 

[Kabel69]

Ok...I made a 3rd attempt to flush heater core and noticed a bunch of air bubbles coming out of the tubes. I left the hose going until I had a nice steady stream going both ways. While sitting in my driveway on an incline I held the rpm at 2k and my heater started to blow hotter. When I let it idle back down in would start to cool off. I took the cap off the recovery tank and gave the upper radiator hose a few squeezes and replaced the cap and held it at 2k rpm again for a little bit. I used my meat thermometer in the vent to see how hot the air was coming out and I got it up to 121 degrees.

This brings me to my next problem. I took it for a little drive and at first the air was hot but I could feel it start cooling down as I was driving. Is this an indication of air still in the system? I made a couple short drives after coming back home and sitting in the driveway holding the rpm at about 2k. I get heat in the driveway but not when I'm driving around. How much air could be trapped in the system if that's the case. I've been giving the upper hose a few squeezes and replacing the cap each time I get back.

I'm a lot closer to heat than when I started but something is still not right.

 

[lincolnshibuya]

did you check your heater control valve if it's working properly, it looks like you're loosing vacuum when under load. Is the air still blowing in the same vent or it switches to defrost mode?

 

[Kabel69]

I replaced the heater valve last weekend. From what I can tell is that it stays open because the hose going into the heater core is hot. It seems to get hotter the more load I put on the engine which makes me wonder if the water pump is going bad. But it only works when sitting at an incline in my driveway keeping it at 2k rpm. When driving around at 2k rpm it gets cooler but when I floor it and the rpms get up to 3-4k I can feel the air get hotter.

My air is still coming out of the vents unless I switch it to defrost or floor and then it comes out those vents.

 

[lincolnshibuya]

best way to diagnose this issue without throwing parts at it is to monitor the coolant temp via a scanner while you're driving. If the coolant temp remains stable and you're experiencing inadequate heating in the cabin it could be an issue somewhere in your HVAC controls (blend door, vacuum) otherwise if the coolant temp fluctuates a lot then it could be a water pump, clutch fan, thermostat issue..

 

[Kabel69]

best way to diagnose this issue without throwing parts at it is to monitor the coolant temp via a scanner while you're driving. If the coolant temp remains stable and you're experiencing inadequate heating in the cabin it could be an issue somewhere in your HVAC controls (blend door, vacuum) otherwise if the coolant temp fluctuates a lot then it could be a water pump, clutch fan, thermostat issue..

I'm always ok with not throwing parts at it. I used my bluetooth diagnostic to check coolant temp. It gets up to 90C which is about 194F and then drops back down to 85C or 185F, so I assume the thermostat works. Blend door actuator is new and I verified the door is working by sticking a camera scope down the vents. I'll have to look into the vacuum part but I assume the heater control valve isn't shutting on me when driving. When sitting in the driveway and reving it to 2k rpm should create some vacuum and the heat works but yet same scenario while driving doesn't. I'm thinking a large sledgehammer should do the trick.

 

[faberj]

Correct me if I'm wrong but the blend door redirects the air through the vents or defrost right. If so mine has been broken for a couple of years now, but I still have heat. What I have had problems with in the past when there is no heat is the thermostat quits working properly. The temp gauge will still read in the normal range or maybe a hair below normal. This happens about every 2 years and once I replace the thermostat I have heat. I have tried after market and OEM thermostats but have had the best luck with OEM.