94 Ls Climate Control And Little Heat

[crow1]

Hello,

anyone know if a climate control unit can cause a low temperature heat? Until recently the heater would run you out of the car. Now on max hot it is not very warm at all. If so, anyone know of a rebuilder?

If not the climate control, other possibilities?

Unit has never been touched. LCD's are still working.

thanks in advance.

Bill in NC

[wwest]

Hello,

anyone know if a climate control unit can cause a low temperature heat? Until recently the heater would run you out of the car. Now on max hot it is not very warm at all. If so, anyone know of a rebuilder?

If not the climate control, other possibilities?

Unit has never been touched. LCD's are still working.

thanks in advance.

Bill in NC

My 92 LS has a heater coolant flow control valve in the engine compartment near the top center of the firewall. The valve is driven by a cable through the firewall attached internally to the reheat mixing vane/door servomotor. If you move the setpoint from max heat to max cool you should see the valve move about 90 degrees, from fully open to fully closed.

If you detach the cable and it doesn't move full travel then the problem is inside the dash, probably the servomotor.

[crow1]

thanks. I will check that. If it is the servo motor, does it require taking the entire dash apart?

My 92 LS has a heater coolant flow control valve in the engine compartment near the top center of the firewall. The valve is driven by a cable through the firewall attached internally to the reheat mixing vane/door servomotor. If you move the setpoint from max heat to max cool you should see the valve move about 90 degrees, from fully open to fully closed.

If you detach the cable and it doesn't move full travel then the problem is inside the dash, probably the servomotor.

[MeBob]

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

[crow1]

thanks. The temperature guage is just below halfway. Is the thermostat still a possibility?

I have checked the control valve and it is functioning properly.

The way this thing just started not heating all of a sudden makes me wonder if there is a sensor bad. The parts lists an in-car temp sensor for the heating system but does not show where it is.

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

[wwest]

thanks. The temperature guage is just below halfway. Is the thermostat still a possibility?

NO

I have checked the control valve and it is functioning properly.

The way this thing just started not heating all of a sudden makes me wonder if there is a sensor bad. The parts lists an in-car temp sensor for the heating system but does not show where it is.

What happens if you put the control in max heat, 85F, and leave it there, do you then get TOO much heat??

Max heat or max cool bypasses the sensors.

And OPEN cabin temperature sensor (little window above the driver's right knee), or even an open OAT sensor (in front of the radiator/condensor behind the bumper) would result in poor or no heating.

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

[crow1]

thanks. The temperature guage is just below halfway. Is the thermostat still a possibility?

NO

I have checked the control valve and it is functioning properly.

The way this thing just started not heating all of a sudden makes me wonder if there is a sensor bad. The parts lists an in-car temp sensor for the heating system but does not show where it is.

What happens if you put the control in max heat, 85F, and leave it there, do you then get TOO much heat??

Max heat or max cool bypasses the sensors.

And OPEN cabin temperature sensor (little window above the driver's right knee), or even an open OAT sensor (in front of the radiator/condensor behind the bumper) would result in poor or no heating.

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

I just changed the thermostat. The old one only got between one quarter and one half. Now it is on half steady.

Got heat for awhile when on max heat. Got hotter when running hard above 3K rpm's. I then turned it down to 80 degrees.Then it started only warm at best again. Now even on max heat it is only warm.

Any suggestions? Could it be the radiator cap not holding pressure enough to put water through the heater core?

[eatingupblacktop]

I just changed the thermostat. The old one only got between one quarter and one half. Now it is on half steady.

Got heat for awhile when on max heat. Got hotter when running hard above 3K rpm's. I then turned it down to 80 degrees.Then it started only warm at best again. Now even on max heat it is only warm.

Any suggestions? Could it be the radiator cap not holding pressure enough to put water through the heater core?

Having changed your thermostat, I'm sure you have checked your coolant level. In some cars, if your level is outside the marked range it will affect how much heat you will get. You also have the possibility of an air bubble when filling up after replacing your stat. Your heater core could be starting to block up. Did you do a flush before filling up the coolant? If not, I would use some radiator flush, set the heater to max heat, and let it run for 5-10 minutes. Then drain and refill. If your heater's only partially blocked you should be able to clear it this way.

[crow1]

I thought about all the above posts. Put a new radiator (reservoir) cap on it and now there is heat. Apparantly not enough pressure to allow water to reach the highest part of the system.

thanks for all the help folks.

thanks. The temperature guage is just below halfway. Is the thermostat still a possibility?

NO

I have checked the control valve and it is functioning properly.

The way this thing just started not heating all of a sudden makes me wonder if there is a sensor bad. The parts lists an in-car temp sensor for the heating system but does not show where it is.

What happens if you put the control in max heat, 85F, and leave it there, do you then get TOO much heat??

Max heat or max cool bypasses the sensors.

And OPEN cabin temperature sensor (little window above the driver's right knee), or even an open OAT sensor (in front of the radiator/condensor behind the bumper) would result in poor or no heating.

Bad thermostat can cause that. In cold weather, engine never reaches corret operating temperature.

I just changed the thermostat. The old one only got between one quarter and one half. Now it is on half steady.

Got heat for awhile when on max heat. Got hotter when running hard above 3K rpm's. I then turned it down to 80 degrees.Then it started only warm at best again. Now even on max heat it is only warm.

Any suggestions? Could it be the radiator cap not holding pressure enough to put water through the heater core?