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Air through Air con

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Theantony
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Air through Air con

Post by Theantony » Sat Jan 23, 2021 3:55 pm

Hi.

I’m getting cold air coming through my air con vents even when it’s not on. This happens when the heater fan is on. I’m not sure it even works, when I press the air con switch you definitely hear it engage and the fan working but nothing seems to happen.

Cheers

Antony.

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635sharknose
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Re: Air through Air con

Post by 635sharknose » Sat Jan 23, 2021 4:33 pm

Well, we get cold air in our vents here as well in Holland, I think it related to the ambient winter temperatures :D .

Just kidding, now serious, you aren't getting any heat correct?

That the air conditioning is engaging and not working is most likely caused by insufficient amount of refrigerant.
Is your car still running on R12 or was it converted to R134a before?
Paul
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1987 635CSi Bronzitbeige

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Theantony
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Re: Air through Air con

Post by Theantony » Sat Jan 23, 2021 4:42 pm

“That the air conditioning is engaging and not working is most likely caused by insufficient amount of refrigerant.
Is your car still running on R12 or was it converted to R134a before?“

I have know idea. How would I find out.

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635sharknose
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Re: Air through Air con

Post by 635sharknose » Sat Jan 23, 2021 5:28 pm

Check the filling nipples on your car, are they R134a, like on the photos, or R12?
Just Google the nipples and you will see the difference.
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wfwright2
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Re: Air through Air con

Post by wfwright2 » Sat Jan 23, 2021 6:07 pm

Depending on which series e24 you have, this is normal, proper operation of the AC/heating system.
On the series 2 two cars (late 82 - 89), the dasboard vents supply either unconditioned outside air or cooled air if the AC is engaged. Airfow is controlled by the middle slider and the individual vent control. No way on these cars to get heated air from these vents. Well described in the owners manual which you should acquire to help expain some of the idiosyncrasies of these cars.

There is a thermal cutout for the AC system, so the compressor probably not engage below about 45f.

If you are a luck series 1 owner, one of those that are experienced in the earlier cars will need to offer assistance.
Wfwright2
Chesapeake, VA 23322
88 M6 Black (5/87)
07 X5 4.8l
02 X5 4.4l I killed, ignored chain rattle, 00 528iT took out by 89 t-bird
87 635csi A. Gone to new keeper, 88 535is Gone to new keeper

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Theantony
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Re: Air through Air con

Post by Theantony » Sat Jan 23, 2021 6:55 pm

635sharknose wrote:
Sat Jan 23, 2021 5:28 pm
Check the filling nipples on your car, are they R134a, like on the photos, or R12?
Just Google the nipples and you will see the difference.
Great thanks I’ll check.Where is this located by the way.

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Theantony
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Re: Air through Air con

Post by Theantony » Sat Jan 23, 2021 6:57 pm

wfwright2 wrote:
Sat Jan 23, 2021 6:07 pm
Depending on which series e24 you have, this is normal, proper operation of the AC/heating system.
On the series 2 two cars (late 82 - 89), the dasboard vents supply either unconditioned outside air or cooled air if the AC is engaged. Airfow is controlled by the middle slider and the individual vent control. No way on these cars to get heated air from these vents. Well described in the owners manual which you should acquire to help expain some of the idiosyncrasies of these cars.

There is a thermal cutout for the AC system, so the compressor probably not engage below about 45f.

If you are a luck series 1 owner, one of those that are experienced in the earlier cars will need to offer assistance.
Yes mine is a mid 82. August. Everything you described is what is happening, but does that count for the steam of cold air I’m getting through the grill above the ashtray.

wfwright2
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Re: Air through Air con

Post by wfwright2 » Sat Jan 23, 2021 7:18 pm

That sounds like one or both of the flaps internal to the heater box has either been jammed by some foreign material or deteriorating foam from the seals, when the AC is engaged the flaps are suppose to move to allow airflow through that grill, then evaporator coil and then out dash board vents. When the flaps get stuck in a partial open/shut position it allows the condition that you have.

I remember reading a discription of a "fix" years ago either on this site or mye28.com (very similar system with same hvac box under dash). I did a simple correction to my e28 about 15 yearrs ago without removing the box but do not remember how I went about it. I think I had to access the lefthand side of the heater box, a pain on my lhd vehicle, but easier, not easy on your rhd example. Assuming because of your location.

The Bently e28 manual has a pictorial of the system which should help if you can find a copy.
Wfwright2
Chesapeake, VA 23322
88 M6 Black (5/87)
07 X5 4.8l
02 X5 4.4l I killed, ignored chain rattle, 00 528iT took out by 89 t-bird
87 635csi A. Gone to new keeper, 88 535is Gone to new keeper

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Theantony
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Re: Air through Air con

Post by Theantony » Sat Jan 23, 2021 7:55 pm

Ok cheers. I’ll pull the havac and have a look.

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Theantony
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Re: Air through Air con

Post by Theantony » Sat Jan 23, 2021 8:26 pm

wfwright2 wrote:
Sat Jan 23, 2021 7:18 pm
That sounds like one or both of the flaps internal to the heater box has either been jammed by some foreign material or deteriorating foam from the seals, when the AC is engaged the flaps are suppose to move to allow airflow through that grill, then evaporator coil and then out dash board vents. When the flaps get stuck in a partial open/shut position it allows the condition that you have.

I remember reading a discription of a "fix" years ago either on this site or mye28.com (very similar system with same hvac box under dash). I did a simple correction to my e28 about 15 yearrs ago without removing the box but do not remember how I went about it. I think I had to access the lefthand side of the heater box, a pain on my lhd vehicle, but easier, not easy on your rhd example. Assuming because of your location.

The Bently e28 manual has a pictorial of the system which should help if you can find a copy.
But with you saying that, the slider for the footwell air is stiff and a clunky when you get to the ends. So maybe that’s it.

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Theantony
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Re: Air through Air con

Post by Theantony » Tue Jan 26, 2021 4:56 pm

635sharknose wrote:
Sat Jan 23, 2021 5:28 pm
Check the filling nipples on your car, are they R134a, like on the photos, or R12?
Just Google the nipples and you will see the difference.
I can’t seem to find these. Hmm. Where are they situated what am I missing.

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635sharknose
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Re: Air through Air con

Post by 635sharknose » Tue Jan 26, 2021 5:35 pm

I have an 87 model, which is different from yours.
On my car they are situated (under the hood) on the right side just behind the headlights. And the other one is left from the suspension.
Paul
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1987 635CSi Bronzitbeige

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