Heater Core

Topic: Heater Core (Read 1483 times) previous topic - next topic

Heater Core

December 03, 2007, 12:49:14 PM

As some of you may know, I've had my hands all over the 2.3 in my '86. I pooped the headgasket last October which resulted in a total rebuild of the top half of the engine.
This also included a total rebuild of the coolant system.
So far, I've replaced the heater core (Ford unit), radiator, water pump, thermostat, and 90% of the soft and hard lines for the system.
There really isn't too much left for me to replace.

The car has an overcooling problem, so I recently made a baffle to cover the front of the radiator. It's a large piece of cardboard with long slits cut into it, so it's a little cornball looking, but it does its job well.
The engine will usually run around the 'M' in 'NORM' on the buttstuffog gauge.

Here's the problem: the heat sucks in this car. The air that comes out of the vents is barely warm, and I've never felt hot air come out - even directly after I rebuilt the cooling system I never felt hot air.
I've changed thermostats more than once, too.
I was driving it today with a warm engine and the heater was putting out air that was probably around 60*.
I felt the hoses going into the heater core - one was very hot (it almost burns my hand) and the other was barely warm at all.
I suspect it's only warm because of the ambient heat in that area from the other hose and the turbo being underneath it.
How in the hell could the core be clogged already?
I just don't understand what's going on. It's like the car is jinxed or something.
Ideas?

Heater Core

Reply #1 – December 03, 2007, 01:09:55 PM

I'd say maybe an air bubble somewhere, but it doesn't seem like it's overheating, so hard to say for sure.

The Chevy I drive does about the same thing, engine doesn't get as warm as it does in the summer, and on a real cold day, the heater doesn't blow very warm air.
Sometime this week, I'm gonna flush the system out, including the radiator, and put in a different T-stat.

Heater Core

Reply #2 – December 03, 2007, 01:48:32 PM

Can I purge the system at the core? It seems like it's the highest point of the cooling system, so would it be likely for an air bubble to be trapped there?

Heater Core

Reply #3 – December 03, 2007, 02:05:17 PM

Could it be mixing cold outside air with the air coming from the heater?
Just brainstorming but could there be a foam seal that might be missing or not put in correctly alowing the system to suck in cold air deluting the hot air from the heater core? Or possably blowing arround the core? I did my heater core a few years back and don't recall how it all pipes together.

Don't even know if it's possable.. but something to look at

Heater Core

Reply #4 – December 03, 2007, 05:55:36 PM

So, what if the blend door isn't working as it should?
Is that possible? I've never gotten too deep into the HVAC system.

Heater Core

Reply #5 – December 03, 2007, 06:07:38 PM

the blend door wouldn't explain 1 warm hose.
cold air blowing around inside the core would
if you squeeze the upper rad. hose will air bubbles come out the cap?

Heater Core

Reply #6 – December 03, 2007, 06:18:27 PM

Quote from: daminc;190964

if you squeeze the upper rad. hose will air bubbles come out the cap?

No. Squeezing the upper radiator hose just makes the fluid level rise - no air bubbles have ever come out.
I've done this on an incline, too, with the front of the car higher than the rear.

Heater Core

Reply #7 – December 03, 2007, 06:29:23 PM

sounds like there's now flow through the core. the core was new also?
does your coolant level go down ever? or purge out?

Heater Core

Reply #8 – December 03, 2007, 07:21:52 PM

If it's a full copper heater core you might try some CLR or the like in it.

I've had decent luck with that on a clogged core.

I've just disconnected both hoses from the hardlines and turned them up at the core and dumped the CLR into one hose until it came out the other and let it sit. The vinegar trick you used on the rest of the engine could work here as well.

Heater Core

Reply #9 – December 03, 2007, 07:43:32 PM

thats a good idea. esp. before a flush

Heater Core

Reply #10 – December 03, 2007, 07:50:00 PM

Just been thinking about that. the core has to be plugged for the hose to be that hot on 1 side and just warm on the other. do what chuck said then flush it both ways starting with a reverse flush