Heater not putting out heat

**thedhgroup** · 09-16-2011, 09:43 PM

It got cold the last couple of days here in South Dakota so I hooked up the cable that goes to that valve on the engine side of the firewall and turned up the heat. There is a problem though. No heat. After the engine was warm I felt the hose going to the radiator and it was hot then I felt the hose going to the heater core and it was relatively cold. I then tested to see of the valve opened and closed with the temp dial and it does. One thing seemed odd and that was the reservoir. It was reading completely full when hot which I suppose is normal but when the engine cooled off it was still full.

Is it possible there is air in the line? What is the possibility the water valve controlled by the heater is blocked? What else could be wrong? Is there another thermostat that prevents coolant from going to the core?

gilbertguy · 09-17-2011, 12:04 AM

This reminds me I need to probably hook up my cable to the heater core valve soon. So give this a try and let us know what you find:
- disconnect the end of the control cable under the hood that moves the heater core valve
- have someone sit in the car with it running and with the system in AUTO and have them move the dial from full Hot to full Cold
- you should be able to see the cable moving back and forth while they turn the dial back and forth from hot to cold
- if the cable moves then your valve that lets the hot coolant into the heater core is frozen or stuck, try moving with a pair of plyers but careful not to damage it.
- If the cable fails to move at all then the valve is fine and you need to trouble shoot the motor that moves the cable or the control panel that the dial is on.

Let us know what you find.

Willie Williford · 09-17-2011, 12:16 AM

gg helped on the heat.
Possible air in the line, or a partial leaking headgasket (sorry).

Willie

**thedhgroup** · 09-17-2011, 10:31 AM

Quote:

Originally Posted by gilbertguy

This reminds me I need to probably hook up my cable to the heater core valve soon. So give this a try and let us know what you find:
- disconnect the end of the control cable under the hood that moves the heater core valve
- have someone sit in the car with it running and with the system in AUTO and have them move the dial from full Hot to full Cold
- you should be able to see the cable moving back and forth while they turn the dial back and forth from hot to cold
- if the cable moves then your valve that lets the hot coolant into the heater core is frozen or stuck, try moving with a pair of plyers but careful not to damage it.
- If the cable fails to move at all then the valve is fine and you need to trouble shoot the motor that moves the cable or the control panel that the dial is on.

Let us know what you find.

I guess I kinda did all that to help troubleshoot the situation. As my kid moved the knob back and forth the cable went back and forth. I took the cable off the valve and moved the valve by hand and it moves very easily.

I guess my next step may be to confirm the valves operation by taking it apart.

**thedhgroup** · 09-17-2011, 10:40 AM

Quote:

Originally Posted by Willie Williford

gg helped on the heat.
Possible air in the line, or a partial leaking headgasket (sorry).

Willie

Leaking headgasket? That ain't good. When I took the cap off the radiator when cold I did not see any fluid but the core is so close to the top that I'm not sure I would. Maybe I'll try to get the fluid from the full reservoir back into the radiator.

Maybe I should just bring it in to my mechanic. He has all the cool tools but thinks I'm a little off my rocker driving a car like that.

Willie Williford · 09-17-2011, 04:00 PM

Assuming the coolant bottle was full when you removed the rad. cap. Was there any pressure in the radiator?
Fill your radiator to the full mark, (to where the cap seal is on the inner neck) start the engine and you will see some bubbles flowing and as the air is expelled you will see the level go down. Add coolant as needed to see the bubbles being expelled. When the bubbles stop, put the cap back on and shut off the engine. Then go to the bleeder valve and hook up a small line to a funnel and fill the funnel up a liittle so you can see the level of the coolant. Start the engine and let it idle. If there are any bubbles inside the system they will exit via the funnel. When the bubbles stop or the level in the funnel starts to rise, shut off the engine. Reinstall the bleeded valve cap and clean up your mess.
Drain the overflow bottle down to the max. level line.
Go drive the car hard to get the temp up. Heavy throttle, at a low rpm should do it as the engine will go way retarded and heat will be built up in the coolant system.
Shut the engine off and see what the level is. The next day....when ultra cold the level should be at or slightly below the max line.
MAKE SURE THE CLIMATE CONTROL is set to the MAX TEMP before the above scenerio..
HTH
Willie

**thedhgroup** · 09-17-2011, 09:13 PM

I got heat from the core finally. I think the root problem was the reservoir. The bleeder hose went to the cap but there was no hose to the bottom. (there is supposed to be one, right?) Anyway I used a large bulb syringe and put it in the radiator to the top and started it up. Some bubbles appeared but not as many as I thought there would be. It was just enough to get some fluid to the heater core so now I have heat. I'll probably have to add more fluid as I go through a couple of cycles of running. I also added a section of hose to the reservoir.

Thanks for the help.

Willie Williford · 09-17-2011, 09:21 PM

Great. Sometimes the simplist things work. Definately bleed the system with the climate control on MAX. The heater core has several air pocket areas in it.

Willie