Ventilation always blows warm air

NaweedMustafa · Post by **NaweedMustafa** » Mon Sep 18, 2023 9:48 pm

Out of curiosity, ventilation blows hot air regardless if the AC is turned on or off? Im having a similar issue with the AC however, this was suspiciously after i got my thermostat and coolant replaced. Didn't bother to call the garage as summer is ending. Anything specific i need to lookout for on INPA? I'll have a look at analog input of the IHKA module

2.5tdi · Post by **2.5tdi** » Tue Sep 19, 2023 4:53 am

In my case it’s always blowing warm unless i set temp to max, then it was hot.
With ac it was cold.

Maybe bleed your cooling system again and check air mix temperature, also check if flaps motors are moving. Mine was at 0% until i set max temp.

NaweedMustafa · Post by **NaweedMustafa** » Tue Sep 19, 2023 4:24 pm

Everything with the rotary dial and the flaps seems to be ok.

Flap position for fresh air and recirculated air went from 0 to 100 and then later sat at 20, so seems to be fine i would guess (first time diagnosing this)

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Only strange thing i see is when temp setting is set to 17 (or 16) I don't see anything else dropping to those values, especially the mix temp sensor. had it on full blast and evap sensor was reading 23-24. I guess i just need to do an airco fluid service when summer comes around? If this was caused by the coolant refresh, i would guess that my engine temp reading would also be higher than normal right?

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2.5tdi · Post by **2.5tdi** » Tue Sep 19, 2023 4:47 pm

NaweedMustafa wrote: ↑Tue Sep 19, 2023 4:24 pm Flap position for fresh air and recirculated air went from 0 to 100 and then later sat at 20, so seems to be fine i would guess (first time diagnosing this)

This is not flap responsible for inner temperature but for source of air. You should look for air mixture flap.

NaweedMustafa wrote: ↑Tue Sep 19, 2023 4:24 pm Only strange thing i see is when temp setting is set to 17 (or 16) I don't see anything else dropping to those values, especially the mix temp sensor. had it on full blast and evap sensor was reading 23-24. I guess i just need to do an airco fluid service when summer comes around? If this was caused by the coolant refresh, i would guess that my engine temp reading would also be higher than normal right?

Exactly same problem as mine. As i see from second photo there was 16C outside when you did test, so mix temp sensor should match that temperature. If that test was with AC on then you probably need AC service aswell, but first make sure that air mix flap works.

Yes engine would probably overheat and if you are not sure you can bleed coolant system with inpa again.

NaweedMustafa · Post by **NaweedMustafa** » Tue Sep 19, 2023 4:53 pm

2.5tdi wrote: ↑Tue Sep 19, 2023 4:47 pm If that test was with AC on then you probably need AC service aswell, but first make sure that air mix flap works.

Aha, for the past year indeed the difference between 17C and 16C was big (somewhat cold on 17 setting then extremely cold on 16), so i guess that explains the air mix flap. now of course its that plus the AC not working as it was turned on during this test. The Mix flap motor, do you know the specific term for it so i can have a look at a manual on ISTA? difficult do access or not? I definitely do not want to go to a garage for such a thing, other than reconditioning the fluid of the AC of course

2.5tdi · Post by **2.5tdi** » Tue Sep 19, 2023 6:21 pm

It is just flap motor, I dont know any other terms. You have picture of mine on 1 page of this thread.
On ista you can check flap position from 0-100%, that is what i would check.
Yes it is pretty difficult to access it (mostly because car is so small) and it is behind other two motors (footwell and defrost i think). You have to remove glovebox and plastic beneath it then you can access it.

It is number 1 motor on photo.

NaweedMustafa · Post by **NaweedMustafa** » Tue Sep 19, 2023 7:08 pm

Hmm, also out of curiosity, is this responsible for the mixing flap by any chance? was set to not active, i later activated it 2 months ago and left it that way. just deactivated it right now to see if changing it was the cause of all of this.

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regarding access to the motor, i'll try and check some manuals and youtube, not looking forward to this task if it requires a lot coming off

2.5tdi · Post by **2.5tdi** » Tue Sep 19, 2023 8:10 pm

I don’t think it is related.
It does not require a lot coming off, just glovebox and plastic beneath. It is difficult because of space, it helps if you are not tall.
Mine replacement motor should arrive this week, i will take some photos of process.

NaweedMustafa · Post by **NaweedMustafa** » Tue Sep 19, 2023 8:28 pm

2.5tdi wrote: ↑Tue Sep 19, 2023 8:10 pm Mine replacement motor should arrive this week, i will take some photos of process.

I would be very grateful for this.

So from what i can gather here, the Mixing motor % (From my 1st picture) should be adjusting depending on the temperature selection, correct?
For others following this thread, on ISTA, it is labelled as "blending flap"

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NaweedMustafa · Post by **NaweedMustafa** » Thu Sep 21, 2023 2:16 am

After some tinkering around on INPA, it seems i cannot control the mixed air flap servo, so thats a telltale sign. Anyone with working flaps that can try this? i also noticed another strange thing. When trying to alter the fresh air flap, it just went straight to 0%, so not sure if thats a servo we can freely adjust

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2.5tdi · Post by **2.5tdi** » Tue Sep 26, 2023 6:34 am

I think fresh air flap is supposed to work like that.

I got motor yesterday but it is faulty (shows short to ground fault), then i installed back my old motor and it now started to work like it is supposed to (mixed air is changing when i change temperature setting). I have no idea why…

Here are some photos. It’s not necessary to remove plastic under glovebox, i somehow forgot and was wrong in last post.

After you pry out motor you have to wiggle it out with hand, install it in reverse process. You have to have it set in middle position, you can just turn motor with hand slowly.

NaweedMustafa · Post by **NaweedMustafa** » Tue Sep 26, 2023 8:54 am

THanks for the pictures! i will have a look. i'm also hoping that it just needs a good clean to work again. I assumed i didn't need air-conditioning as the outside temps are dropping however, with the mix flap not working, the car constantly fogs up...