Heater stopper working gradually.. (first by a little, now no heat at all). All vents blow air, including A/C works perfect still. All ***** work i can adjust the air power, the vents, inside to outside air etc. Checked behind glove box the switch to change cold to hot air is Cable so issue is not there. Car heats fine and doesn't overheat the radiator is properly filled. There is a very faint clicking coming from heater case only when dial turned to hot and air is on9what could that mean).. I have accepted i will need to take the entire dash apart to get to my heater housing to replace it.. but i would like to hopefully just replace the key broken piece instead of the whole thing.. I would first need to order it before I start this task.. that is my dilemma.I suspect it is either the air mix door, the heater core is blocked, (or possibly the entire heater core).. Am i on the right track..can anyone offer me any other advice or angles i may not see?? any solutions or possible problems it may be would greatly help! more in detail the better!

 

It is not uncommon for a heater core to catch trash over the years and clog up. I have never had to replace one because of it. Remove the heater hoses and flush it with a garden hose with a small tipped nozzle. Flush it both directions. Sometimes i have to use air pressure to unclog them. Since you lost heat a little at a time i'm sure it is just clogged though.

 

All right I will start with that it would definitely save me time and money. Hopefully it's as simple as that and I've been stressing over nothing!

 

Ok so I have flushed the hoses both ways. I removed them from firewall to flush not engine would that have made a difference? I have also added the coolant back. It doesn't seem the heat is back I only drove it for a half hour tops.. Should the heat come immediately back? Or does it take awhile.. What would be my next step if this didn't work?

 

Did you use high pressure or just a garden hose? It takes high pressure. What came out? Was it rusty looking? Was there trash? When you grab the hoses at the heater core is one hot and the other cold?

http://www.aliexpress.com/item/2-Pcs...749656989.html

A nozzle similar to this is required.

 

Yes I used that. There seemed to be a small blockage that came out.. I ran it both ways until the water ran smoothly with no discoloration. Should the heat come immediately back? If it doesn't shouldn't try flushing the hoses from engine and not from firewall? Could the thermostat affect the heat in the car? (Engine temp is fine does not overheat)

 

The thermostat could be sticking open. It does not coincide with loss of heat gradually though. Unless the spring is just wearing out gradually and opening too soon or the heat loss was intermittently lost. It is probably time for a thermostat though if it has not been replaced.

 

I will replace the thermostat either way. Should I flush the hoses again, this time through the heater core? If the heat still does not return is my only other option to replace the heater core?

 

Does that mean you did not back flush the heater core the first time around?
If you found gunk in one hose you sure have gunk in the heater core.

 

Yeah that's what in was thinking it was easier to take the hoses off the firewall than from the engine block. So when I flushed it, it didn't go through the heater core.. That would defenitely make a difference right?