Could be that the heater core is slightly clogged. Take a pressure washer (like one at a car wash if you don't have one at home) and flush out the heater core in both directions. Back in the mid 80's....I had to do this to my Maverick every two weeks or so if I wanted heat.
More pressure on the core very possibily cause leaks. Better yet replace the heater core and be done with that part. I always fine alot of debris the unit I have removed. At the same time clean and repair and breaks in the case and hoses. If is a daily driver by another HVAC unit, rebuild it and have it ready to install over a weekend. IMHO http://mmb.maverick.to/showthread.php?t=57977 Can't be a bad as replave the core in my 96 Ranger (remove the whole dash unit) over the weekend. Rick
I did flush it in both directions with just normal water hose pressure. Is it true that it will only work if the water flows in a certain direction? I can't fathom how that could be right since it flowed both ways very easly, but who knows. The car does have factory AC. I just asked O'Reillys for a thermostat for it, I wasn't smart enough to specify a certain temp range. CommieHook
Do you want water that just got cooled off in the radiator going to the heater or hot water about to go into the radiator going to the heater?
I see what you're saying, but one of the heater hoses pushes the water and the other returns it to the system. Does it matter which heater hose is attached to which heater core outlet/inlet? Either way it circulates through the core. Or am I oversimplifying? CommieHook
Doesnt matter at the core in this car. This is getting too complicated. With it at tmep are both hoses at the core hot. If they are its flowing fine. You ahve a problem in the box. Door etc.
A few thoughts. As asked before, do your heater hoses get hot? By hot, they should be to where you can't hold them for more than a few seconds. Do you hear a " clunk " when you move your Cool - Warm lever? You should. If the heater hoses don't get hot, but the engine and radiator top does, do you have the outlet heater hose connected to the thermostat housing? If so change it's position to come out of the head ( on a 6 cyl ) or from the intake manifold ( on a V8 ). The return hose should go to the water pump on either engine. As for the temp control lever, if you don't hear a " clunk " when you move it back and forth, the cable may have come unhooked. It's a contortionists job to get to, but if the cable doesn't move the blend door properly, you won't get good heat! Good luck! I know it's getting cold where you are! By the way, that's a nice looking " 51 " in the background! How about blowing up the flat on it!
I just don't understand.....I drove the car in town and back home, about 40 minutes of driving. I had the heat on the entire time, it might have got just a tiny bit warm, maybe..... Park the car, raise the hood, grab the heater hoses. One of them is pretty warm, the other is downright cool. So it would have to be that valve is stuck closed or that the heater core is clogged, right? But I removed the valve and it is open by default. And I flushed the heater core both ways and it was in no way clogged. Ugh. So now what do I check? By the way, I did check the temp control valve and the cable is opening and closing the "door". Thanks for your help guys. CommieHook
Hoses shud be more than just warm as Simple Man states. If ur engine is heating the coolant properly I got think it's ur heater core, since u have bypassed the valve. I can't see it being anything else. I know u flushed it out. I think ur going to hve to remove the heater box an examine the internals and while u have it out - think new core. U do have the thermostat in w/ the flow in the correct direction - Right?
Pull the vacuum line off the bypass valve, plug the line, go for a drive and see if you get anymore heat.
When I replaced the thermostat I put it in just like the other was in, but I do feel like it is opening because I watched the water in the radiator and saw the water level change and the water warmed up when it got to temp and opened. Is removing the heater box difficult on a Mav with factory AC? CommieHook
It depends on who u ask - removed mine last winter and brought it in the house for rehabbing. I put it bak early spring this year. It's not to bad. I wud suggest takin the pass seat out since ur going to be under the dash quite-a-bit. It was easier for me that way - others may have diff opinion. I believe there is four fastners holding it in, 3 in the fire wall and one in far pass side holding it to the dash. One man can remove the unit but two people to replace it - at least for me that's how it was. I have a CD with all the parts and drawings of the car which makes things easier. I have only bn working on this kind of car two years but learned a lot and got a lot done on my car. I have to credit a lot of my success to being on this forum. There are many folks hr w/ decades of experience and things easier for them cuz they know exactly what their doing. Check out the link below; Jeff has a lot of gud stuff on his site and vry experienced w/ this stuff. http://1bad6t.com/Maverick/maverick.html
Just did what DDB suggested, disconnected the vacuum lines from the inlet valve and took it for a good long drive. No change. The heater hose that has the inlet valve on it, which is the upper, was really warm/almost hot, on both sides of the valve. The other heater hose, the lower, was downright cool! Which would suggest to me that the heater core is completely clogged up. Yet just this past weekend I flushed it from both hoses, both directions, and it flowed just fine. (Sorry to keep repeating myself.) Unless Eastern Raider was right and the hose are reversed and it does matter which hose goes where. Mojo, I do plan on taking your advise and pulling the heater box altogether and replacing the heater core at that time, but I won't be able to get to that for a couple of weeks and since this is my daily driver I am trying to get it a little warmer so my young ones won't freeze on the way to school in the mornings. Again, thanks for all your suggestions. CommieHook
Ok Hook! If it's getting hot water up to the box and no heat or the return hose is cold, it's got to be a problem in the box - IMO. It does seem strange that u flushed it and still not getting hot. It's flowing but prob not like it shud. I understand if the car is a DD u have to pull it apart when time permits. Being as ur in Ark u can drive a while longer than we cud here B4 having to have heat. We're gettin gud frost hr in the AM and going w/o or just a little heat is not an option. When U get it solved U shud get heat big-time. Wished my AC worked as well as the heat. Curious to know what u find.
