924Board.org

kenaijoe · Joined: 13 Aug 2006 Posts: 4 Location: MO

Hi: Just purchased a 924 and noticed that even with the AC on, there is major heat coming throough the vents....I have the controls set to shut it off but I can't figure out why I'm still blowing hot air...by hot Imean engine hot...not outside air hot...any ideas would be appreciated...thanks....pat

alexvex · Posted: Sun Aug 13, 2006 7:38 am Post subject:

I've got that problem too..no clue why though

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--Alex--
1992 Porsche 968 (VW 2.5L I5 Turbo swap in the works)
1995 Audi 90 Quattro Sport (4.2L V8 Swap)
2010 Touareg TDI
Past Pcars: 80 931, 87 924S, 87 951

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

Have you checked that the water-control valve for the heater is not jammed open?
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1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you

924RACR · Posted: Sun Aug 13, 2006 11:41 pm Post subject:

This is a very common/well-known problem with the 944's... there's a clip for the control flap that's plastic and often breaks; when it does, you get hot air all the time. Assuming it's not, as Peter points out, a heater control valve that's not operating properly. Check out Clarks' Garage:
http://www.clarks-garage.com/shop-manual/hvac-01.htm
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
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3d914 · Joined: 11 Aug 2006 Posts: 28

924RACR,

Thanks for the info, as I have the same problem, but the link is for 944's. The 924S has the 924 interior with quite different setup. Is there any data on the 924 setup for similar problem? I looked on Clarks site, but nothing like this for 924.

Where is the water-control valve Peter mentioned?

TIA,
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Gerard
74-914 2.0L Ravenna Green
87-924S 2.5L Alpine White

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

My 79 did this, as does my 80. Take a look at the heater control valve while an assistant operates the lever. If the cable has slipped, the valve never closes.

You can adjust the cable itself, sort of like a bicycle cable at the valve end.

rasta
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WeiBe (1987 924S 2.5t) - 931 S3

D Hook · Joined: 02 Nov 2002 Posts: 3158 Location: Omaha, NE

924RACR · Posted: Wed Oct 04, 2006 11:37 pm Post subject:

If you have constant heat in a 2.0L car, your heater valve is probably leaking and allowing continuous flow of coolant, or the cable that controls it is not properly adjusted.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

3d914 · Joined: 11 Aug 2006 Posts: 28

OK, let me try again.

I have an 87 - 924S. I attempted the 944 fix from the link provided. I even went out and bought the parts. But under the dash - near the steering column - my setup is nothing like that shown in the illustrations for the 944.

So I concluded the the 924S in fact has a system more like the 924's than the 944's.

I will try the "heater control valve" fix suggested, if someone can indicate where its located. I only have the 944 book, and haven't purchased the 924 book.

TIA,
_________________
Gerard
74-914 2.0L Ravenna Green
87-924S 2.5L Alpine White

924RACR · Posted: Fri Oct 06, 2006 9:58 pm Post subject:

It's above the bellhousing, back of the engine, by the firewall.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Smoothie · Posted: Sat Oct 07, 2006 12:41 am Post subject:

3d914 · Joined: 11 Aug 2006 Posts: 28

Thanks guys. I'll take a look in the next week and get back with what I find.
_________________
Gerard
74-914 2.0L Ravenna Green
87-924S 2.5L Alpine White

Smoothie · Posted: Sat Oct 07, 2006 7:56 am Post subject:

A nice long pair of needle nosers like these come in handy when dealing with the heater valve and hose connections back there. You'll at least have to remove the coil to get at it [actually, this applies to the 924NA/931 - I don't know about the 924S].

Another possible problem area is the controls - with the change from the early 924 hvac to early 944 style, the controls were changed to plastic from metal, so those levers inside the dash that move the cables are plastic and can crack. Mine did.. Instead of buying new, I was able to repair and reinforce those parts with wire and epoxy (and a lot of patience) - with the reinforcing, now those pieces are stronger than if I'd replaced with new controls.
-But check the operation of the heater valve before opening up the dash.

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