924Board.org

[melon]

I have a bit of a problem with the heating in my car, and being that it's now getting colder outisde I suppose I should ask to see if anyone knows how to fix it. My defrost vents seem to blow hot air just fine, but my middle console and side vents blow freezing cold air, as if it's coming from directly outside. At the moment I don't have a clue how to fix it, so I've taped over the center vents so the air doesn't blow into the cabin, and shut the side vents. But since only the defrost vents work the car doesn't warm up very quickly, in fact doesn't seem to really warm up at all.

Thank you for any advice and help you guys can give me.

-Liz
_________________
1980 n/a with EDIS and Megasquirt II Injection v2.684 betacode.
Porsche - Live it, Love it, Fix it

[timstar92404]

what year is it?
_________________
78 924 sold.
85.5 944

[melon]

it's an 80 n/a, though I'm not sure if that makes too much difference for this sort of problem, correct me if I am wrong.

-Liz
_________________
1980 n/a with EDIS and Megasquirt II Injection v2.684 betacode.
Porsche - Live it, Love it, Fix it

[Smoothie]

Heaters were changed at some point in '82 and I have the later version in my car. Not that it matters much - I don't know much about the inner workings of either, but from a look at the diagrams, your top control lever should control the outer flap that you can see from the engine compartment - so to start with, see if that flap opens and then closes completely as you move the upper lever. Your middle lever should operate the water control valve and that's apparently open if you're getting heat out the defrost, so your prob shouldn't be with that. It's tough to tell from these pics what the lower lever controls, but I'm guessing it opens/closes a lower flap that controls airflow to the footwell area. Actually, it looks like the passages to the defrost and middle vents originate from a common area inside the heater box and I don't see any flaps there to alter the flow between them, so why you'd get hot out one and cold out the other isn't making sense.
Anyway, to start - make shure the upper lever moves the engine comp flap, and the middle lever moves the arm on the water valve (below the coil in the engine comp), and the lower lever moves a flap down below (if you can locate it).

Then if all the flaps check out ok, you might have to start suspecting the water flow - either a valve problem or a blockage (formed for instance by a build-up of something like radiator stop-leak that might have been used by a previous owner.
_________________
"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[CMXXXI]

The answer is, that the air directed through the side vents and the center vent in the dash is air directly from the outside, before it has passed throught the heater core. When you slide the bottom slide to the right, it redirects the <heated> air to the floor, and when the slide is to the left, the <heated> air is redirected to the defrost. Look at the photo below, and you can see what I mean.

All air comes in from R2D2's head, and air to the side/front dash vents is blow through the round ducts on the left in the photo (another one on the other side). You can see that these ducts come off the chamber that is above (before) the heater core. When the slide is operated, air that has not gone through the dash vents is either directed to the floor (sort of oval vent at bottom right in photo-another on opposite side) or it is directed up through the large rectangular vent which goes to the defrost vents below the windshield.

The bottom line is that, by design, you won't get heated air through the dash vents. The best you can do is to close off the dash vents so all the air coming from outside is blown through the heater core and goes either down by your feet, or up to the windshield (or both).

Last month when I replaced my heater fan & core I replaced all the worn out weather stripping and seals on the damper, vent hoses & flaps and such. Doesn't make it any warmer, but at least there aren't as many leaks now.

(edit Jan 4 2005 - new server location)
_________________
'79 Eurospec 931

[-nick]

We should have an area dedicated just to cmxxxi's pics!

You may also want to double check that the coolant is bled well. The back of the head is a high spot and easy for air bubbles to get trapped in.

I never could get any decent amount of heat out of the early heater. That's why I went through the ridiculous process of converting to the later setup (only recommended if you like torturing yourself!).

Time to add electric socks to your christmas list?

best of luck
nick

[Smoothie]

Interesting how that works. Less sophisticated than I'd imagined, but nonetheless interesting - I was giving ol' R2D2 credit for being more high-tech than that. Oh well..
One advantage of the newer version then, is you can have hot air from the center and side dash vents.

I'm imagining adding a fan under the dash plumbed-in to blow interior air into R2D2 and recirculate air rather than always pull in all fresh cold air for heating. Hmmm....


Mine put out negligible heat until a couple years ago when I found a clog of radiator stop-leak that had built-up near the heater valve.
_________________
"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[numbbers]

Yep, you have to close the dash vents in winter. Put them in the defrost position.
_________________
1980 924 Turbo