Rear heat still not working properly.

Make sure the flapper doors that control air flow within the air box are moving properly. With the engine hot and the heat turned up, see if the hoses to the rear are hot.

I took all the things apart to expose the heater core and watched the actuators work, and they moved properly. I felt the heater hoses going to the rear and they are not hot. I cannot remember which hose leading to the rear hc is hot, but only one is--I think it is the hose coming off the quickconnect...If I feel the two hoses at the rear leading into the hc, they are not hot. I was thinking air was trapped, but now I have no idea. I am really at my wits end on this thing. What could be causing hot coolant from not going through the rear hoses? The heater core is not clogged as I flowed water through it. Does that mean it is still not bad? What else could it be? I appreciate any help to get this resolved cause we are in for a cold winter.

Check the valve controlling coolant flow to the rear. Something is blocking the flow if neither hose is hot. Valve not working, plugged hose, or something similar.

Ok, got home from after driving across town and the hose farthest to the rear is hot, and the other line is not. Also, my upper radiator hose is very hard now...I sure hope there is not a head gasket issue now. A service place in town told me there is another valve in that line at the rear heater core, but I don't see one. I will look again. The coolant comes to the heater core and that is it--it is not going through the heater core. A place in town told me my gauge should be showing hotter than it is...it is at the solid line between the 100 and the 210 degrees. There are three small lines in between the solid lines, so I am not sure where it...Approximately 155 degrees? What a ridiculous numerical division at that gauge...There has to be a reason that coolant is not getting through that rear heater core.

Yeah, 155 sounds pretty low. Normal operating range is between 180 and 200. The stock thermostat for your vehicle is listed as a 195 degree model. This means it opens at 195 degrees. None of my drawings show the heater control valve for the auxiliary unit. You'll need to trace the heater hose until you find it.

The upper radiator hose being hard may be due to increased pressure because the coolant isn't able to flow throughout the system.

It's looking like you may have a plugged up rear heater core. You might try backflushing it with water pressure from a garden hose but you may ultimately have to replace the core.

Absolutely it sound like that would be the case, but I have flushed it twice--twice at the heater core itself, and twice in the lines...I did the heater core first, then the lines separately with lines disconnected at the heater core and at the hcv area...I then connected the heater core lines and flushed at the hoses in the front in a "U"...it all flowed properly...if it got plugged again, I can check that again. I am not sure what has happened. Perhaps the rear heater core is not freeflowing enough and needs replaced. Have you heard of this happening before exactly like this?

Yep, sounds like you need to replace it. Be sure to flush the rest of the system thoroughly first.

Since the rear heater core is a part of the overall system, any contamination can be transferred to the rear heater core, as well as the front core and the engine block. Until and unless all of the contamination is removed from the whole system, it can very easily dislodge from where it is and move to the rear core.

I took the lines lose again and flushed out the rear heater core. Unless there is still air trapped in the system, I don't see why coolant is not making it back to the heater core. I am almost positive that I hooked up the lines at the heater control valve properly. I don't think there is a way to hook the lines up improperly. Is there another control valve between the engine and the rear heater core? A place in town said there was, but I cannot find one...thanks...

Check the rear heater box. I'm not seeing any diagrams with hose routing, but I would think that there should be a second valve controlling flow to the rear core.

A service place in town told me there was, I just don't see one yet. I have the panel off and the hc exposed so I will look that tomorrow. This system should not be that difficult to diagnose and repair, but things happen, and it is a learning experience for me. I truly appreciate the help.

Wrenchtech, Half of this picture and legend are cut off...5,6,7, and 8 of the legend and the right side of the pic cannot be seen...is there a way you could send it to my email? dcplace2007@yahoo.com Thank you very much...

Try this

The valve itself

Thanks buddy--those look good, I will look at these and the vehicle here in a little bit...since I am keeping this vehicle for a while, I was wondering if there was an online repair manual that is worth buying? I have heard of several, but I need one that is specific (not like the Haynes manual or Chiltons)...

You can contact Chiltons or Haynes and get their professional books. They're about 4 inches thick. Or you can a parts and labor guide. Not sure if you need a resale license for them or not, but I'll ask my father the first chance I get and let you know what he says.

www.alldatadiy.com They will sell youy a single vehicle subscription to the same database that we use.

That number 5 looks like the heater control valve solenoid...this actuates to allow vacuum to the hcv when the a/c is kicked on. This is working properly. When it actuates, it shuts off the heat to the front heater core. My concern is if there is a valve that control the rear heater core. As of now, I don't see any in the line...

That valve and solenoid IS for the rear. There is no valve for the front.

Hmmm, I am going to take a picture of the way I have the hoses hooked up and post them. You are definitely helping me progress to resolve this matter. I will definitely send some money your way once we get this resolved...

Donations just go to operate the site.

Here are two pictures showing the setup of the hoses going into the hcv...larger hose to quick connect and smaller hose to water pump. The two connections on the hcv, on the left, as the hcv sits are to the front heater core. The two connections on the right of the hcv run down the two lines to a tee and a Y that are in line with the rear heater core supply and return lines...I believe it is hooked up right, but I may be wrong. The hvc vacuum line goes up to the solenoid, which you say controls the rear only? The only time this hcv actuates is when the a/c is turned on, stopping heat to the front. This is the only valve that I know of, and could not see the valve that was in the pictures you posted.

I believe the 2 hoses in front of the valve go to the engine and the front heater. The valve controls the third hose coming out behind the valve which should be the input to the rear unit. The other hoses that are tee-d should be the return lines from both front and rear. I'm not positive but I believe that is how they are hooked up.

Does it look like it is hooked up properly? Also, is the hcv open or closed before the vacuum is applied. When does vacuum get applied? Does it happen only when the a/c is turned on?

You can test all that stuff with a hand held vacuum pump and vacuum gauge.