Heating problem in my 92 MX-3

[kevace1]

Hey guys......

I'm having an issue with my MX-3. The heater just will not work. Here's what I have tried and done so far.....

The air mode flap works, you can hear it change from heat side to the ac side. I just change the thermostat, even though my engine never overheated or stayed relatively cold, always reached regular running temperature (in the middle of the temp gauge).

I disconnected the hoses leading to the heater core and ran my garden hose through it, and water flowed through it both ways.

I flushed my cooling system and replaced with fresh mix or antifreeze/water. I always check my radiator filler cap before I go to use it in the morning and its always right at the top of the neck.

My heater core does not get hot at all.....I let the engine run and warm up and I can touch the heater box and its COLD!!! Like the coolant is either not even there or the coolant is cold itself.

Any help with this subject would greatly appreciated....winter is a coming...please help asap.


Kevin

[Mooneggs]

not sure... I know my heater doesn't work very well either and I haven't taken the time to figure it out... bump for somebody who knows...

[shameem]

You may have a blockage in the coolant line - warm up the engine to operating temperature (needle at middle of the gauge) - take off the coolant lines going to the heater core and crank the engine (dont start it) - see if coolant shoots out of the line.
Also you may have installed the wrong thermostat or installed it the wrong way - double check...

One good way to heat up the coolant is to take it on the highway for a bit and then get off and idle for a bit.....

[kevace1]

well i did get a regular thermostat at the local autozone. But the coolant lines that lead to the heater core are HOT, both...but if you go to the heater core box itself its cold. As i said before...I ran a garden hose through it reverse of the regular flow.

what i want to know for certain from somebody is if the pipes coming out of the firewall, are those PART of the heater core itself? or is there another connection inside of the heater box? According to the images on the shop manual, its all one piece but a little verification from someone that may have taken apart eh interior already would be helpful. That would i guess be my last draw. I really cant think of anything else that could be a culprit.