The heat will not work in my car. I get no heat throught the floor or defroster vents. I flushed the heatercore with water and compressed air. It flows really smooth. I took the thermostat out and ran it open loop. Still no heat, jsut cold air.

Any ideas?

 

Are you sure it is flowing coolant through the core?
Maybe take a small section of clear tubing and a duel male coupler and first see if is even flowing through the core.
I think I read somewhere that the heater system can sort of vapor lock in a sense and trap air in the core not allowing fluid to run through it. Though that would seem almost impossible if the core was not clogged, and it was hooked up correctly with the high pressure side and low pressure side where they belong.

 

If you have coolant, and you have flow, you have heat. 99% of the time no heat means low coolant.

 

1) No AIR flow from the heater & defrost vents?
Check out the heater/AC controls for loose cables and (IIRC) vacuum hoses that control the flaps in the heater.

2) You HAVE air flow but it's cold even with heat set to hot?
Same as #1, plus, check the water hoses/tubing from the engine compartment to and from the heater core - if they are hot, hot water is getting to the core, if not something is blocked or routed wrong.

 

Can you see the vacuum hoses from behind the golve box? Or do I have to take the dash out? Also can I take out the heater consol form outside the dash?

I felt the heater core hoses and they were warm. The water form my gardenhose was flushing smoothly through the heater core also, I dont believe its clogged.

This tells me that it could could possible be the flapper door that switches the heaterbox form cold to hot. It could be stuck on COLD

Does the "heater core" make a noise when switched form hot to cold?

 

Maybe there is a giant "air pocket" in the heater core, i could try and flush it again, by keeping water in the core and pushing any air out, then hook the hoses back up again.

I think the hoses felt "warm" beccuse the rubber had absorbed the engine heat, because I dont remember them feeling "hot" while engine was at normal running tempature.

Ill keep pluging away, any sudjestions are grealty apreciated.

 

the heater core lines should be about as hot as the other coolant line (rad hose etc) pinch one of the line together with your fingers and rev the car up do you feel flow? if one line is hot and one cool the core is plugged possibly by air. if you think it is air just loosen one of the clamps on the core with it running and let some coolant flow out. if both lines are hot then you have a door mixture problem

 

Im having a similar problem with my heater not blowing hot air at all. Can you get to those clamps to loosen it without taking the dash out?

 

Not really. YOu can flush the heatercore form the outside of the car. Just follow the hoses on the firewall that connect into the cooling system and motor, and disconnect there.

 

Can you post pics of said hoses please? I couldnt find them when I looked.

 

oops, double post.

 

The heater-core hose connections are on the engine side of the firewall, one above the other, just behind and below the ABS unit.

 

Ok thanks. Can I get to those from above the engine? Or will I have to remove the ABS/go from below?

 

You may be able to get at them from the top without removing anything. With the pre-cat in place, I don't think you can access them from the bottom. If it's too tight, you can remove the ABS heat shield (remove the 2 bolts holding the ABS and the shield nearest the engine, and loosen the 2 bolts toward the fender holding on the ABS). The heat shield is a tight fit, but you should be able to get it off. I had to trim it slightly near where the 2 bolts go through it to get it back on.

I took the shield off and replaced it when I installed my DP and replaced all my water hoses.