ive been trying to fix my heater (its cold here :P ) many people say the heater core might be clogged. 2 questions.

1) both hoses going to the firewall get very hot. if one is an in and the other is a "return" if it was clogged, wouldnt one of the hoses not heat up?

2) what is the procedure to attempt to unclog it?

and i know the heat only works at the feet and defrost. and neither produce heat.

 

if both hoses are the same temp i can't see it being plugged. i read a post awhile ago about some one hooking up a pump & flushing it thru backwards to unplug it. they used some type of cleaner & let it flow for abit. said it worked, can't find the post right now but search it's there somewhere

 

^ https://www.rx7club.com/showthread.p...ht=heater+core. It was bajaman that posted about unclogging it that way. But I agree that it doesn't seem to be the problem though.

 

I will just add to your thread as there is no need to start a new one for same problem…hope you don’t mind


How much is a new heater core?
Has anyone purchased one from Ray recently and could give a estimate on cost?

Do you have to buy the whole plastic housing assembly, or is it possible to just purchase the core separately and swap it out?

If a core flows well and heats up correctly, what is the likely cause of no “hot” air blowing? My core reaches ~74C , and when blowing air across the core with a fan (HVAC doors manually opened), seems to supply much warmer air than when installed in the car.

Both my HVAC actuators physically work according to the manuals test procedures. But i cant verify they are in the correct position when the heater controls are triggered, because of the simple fact there is no way o run the heater under "stock" conditions without the entire dash mounded, and impeding the view of the heater gates.

Are there issues with the controllers at all that would not allow them to control the HVAC correctly sometimes? Similar to what we see with the AC issue and PFC perhaps?


Any tips to make the heater work properly before I throw the dash back in?

 

Back in October Ray quoted me $341.71 for a new heater core. Mine blows hot air - it also blows hot coolant.

After looking at the cost of the core AND the labor required to swap it out I decided it doesn't get that cold in Texas...

 

I dunno much about heater cores except that they are sharp and to be careful when you change one.

However, seeing the same temp on both hoses from the heater might not mean much. The cooling system is continuous, so once the car is warm I would expect both of the hoses to be of similar temperature.

Dave

 

^ Dave is right. Even a tiny trickle from the return will heat the hoses up to the same temperature.
It is pretty easy to check the flow per my original thread.

I was SO happy I was able to fix mine because frankly....even as inclined to tackle ANY automotive project as I am....changing out the heater core had me saying, "Meh...who needs heat anyway...."

 

Thanks habu2 did you find out if you have to buy the whole plastic housing assembly, or is it possible to just purchase the core separately and swap it out?

was the price quote merely for the "heater core" heat exchanger, or the heater core assembly? did you make the distinction clear when ordering?

i will call him monday but it would be nice to know what to expect..

hopefully the assembly is that price, because i am fairly certain my core works fine, but i want a properly working heater.

 

I just sent Ray the part # out of the FSM and he quoted me on that. The FSM link is in the stickies...