But do you think that if one of the motor went bad, I wouldn't get an error through scan?
Should I change it anyway just to see if that solves it?
Should I change it anyway just to see if that solves it?
Does anyone actually know how to fix hot air from passenger side vents with A/C on?
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You might not see an error, sometimes the plastic linkage arms break as well. Ideally you need to start taking your dash apart to check all the linkage arms and actually see if all the motors are working, but that is a pretty big job because the motors are dotted about in different places and most of them are very hard to get to. This is why I've given up with mine for now.
I just took out my glovebox today, everything seems to run just fine from that side. I don't really know what to check anymore. Through OBD11 all the flaps seems to turn normally but I think it only register the motor from the glovebox side, not the actual flaps
On the A6 there used to be a common fault where the drivers side vent were hot and the passenger side vents were cold, it was not caused by the distribution housing inside the car, it was a fault with a coolant valve inside the engine bay. The fault happened on my C6 and after replacing the valve the temperature was normal again on both sides. Maybe worth looking at the A3 coolant system diagrams to see if there is a similar valve system on the 8V models.
This what what the valve unit looks like on the A6.
This what what the valve unit looks like on the A6.
I don't know if my recent experience will help, or even if it's relevant, but I was having a problem in my S3 with lack of heat, even when it was frosty outside. Turned out to be a defective valve: Part No. A4HO 121 671 D 'Coolant Pump/Valve' (£116.58 + labour + vat).
I always have the right hand A/C knob turned on 24/7 (stops misting up in winter and keeps things breezy in summer) and the left hand Auto knob I also have turned on and let it do its own thing. The passenger side is set at 74 degF (the wife's a chilly mortal) and my side at 70 degF and, since the fault was rectified, we've been perfectly comfortable once again.
I always have the right hand A/C knob turned on 24/7 (stops misting up in winter and keeps things breezy in summer) and the left hand Auto knob I also have turned on and let it do its own thing. The passenger side is set at 74 degF (the wife's a chilly mortal) and my side at 70 degF and, since the fault was rectified, we've been perfectly comfortable once again.
How can I check that? Through VCDS or OBD11?
And where exactly does it go in the bay? I looked but no luck..
And where exactly does it go in the bay? I looked but no luck..
Not sure if your question is for me, Alin, but I'm no expert unfortunately. I find that if you press in the left hand knob so that the red light in the centre comes on, that seems to get the system to call for heat up to the temperature chosen by the individual thermostat knobs. Not all versions of the A3/S3 have the same heating & ventilation panel though, so a quick read up in the manual might also help. This pic is borrowed from elsewhere, so not mine, although the same version as in my car (I never have understood what 'eco' setting means!):
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According to http://www.manualesaudi.com/AudiA3/en_GB/onboard/o_m00248.htm
The "eco" mode*1) is activated if you press the AUTO button briefly while automatic mode is active. Fuel is saved in "eco" mode* because the settings respond more passively. The "eco" mode* is on when eco appears in the console display. The "eco" mode*is deactivated when you press the AUTO button again
The "eco" mode*1) is activated if you press the AUTO button briefly while automatic mode is active. Fuel is saved in "eco" mode* because the settings respond more passively. The "eco" mode* is on when eco appears in the console display. The "eco" mode*is deactivated when you press the AUTO button again
Appreciate the guidance Craig, thank you. If the settings 'respond more passively' in eco setting, what exactly happens? Does it just take longer to adjust to temperature variations, or what?
That I got it but I just can't seem to find the control valve in my engine bay. There are no diagram for this, I looked for days...
I don't think the S3 has such a valve, I believe all the 'mixing and diverting' of hot air is done in the cabin via the heater flap motors rather than a valve in the engine bay diverting hot water into the cabin, I'm pretty sure hot water is piped into the cabin permanently and then distributed as required by the heater flap motors. I may be wrong of course. FYI I still have the some problem, I'm currently unemployed again due to COVID so I just can't justify giving an Audi an open cheque to sort it out.
You are correct in relation to the 8V platform not having individual heat exchange valves. The ones pictured above are for the A6 which has a 2 zone heater core. The valves limit coolant flow to each side of the heater core depending on selected temperature in each zone for that system. For that platform they have been known to hold air pockets and seize up.
We do have valve in our system which controls coolant flow to our single zone heater core (component 10 in alpesh26's link above). This is used to divert coolant to the rest of the engine if not heat is requested by the climate control head. As mentioned in a previous post, this valve may be a culprit but symptoms would be no heat out of all vents or limited heat but equal across all vents. These N82 valves have been known to fail and let coolant into the connector so may be worth checking to be safe.
If you are experiencing issues with just one vent, it is most likely due to a temp sensor or flap motor inside the cabin. I would also make sure you verify the issue with the climate system set to Auto and Eco mode turned off. If you still have an issue, check faults and see if there are any range faults for any flap motor. There have been cases where these flap motors can freeze up. I would run the basic setting (via VCDS) to relearn all flap motor end stops and see if that fixes the issue. If it returns, most likely you will need a new flap motor.
Lastly, the temp sensor in the ducts can give a false reading (I have not seen this though). Simply run the system as above and use a temp gauge in the vent outlet. Compare your reading to what the measuring values are reading in the climate control head.
VCDS will be your friend here as it can help you complete the above diagnosis. Hope that helps you out.
My issue is the passenger vent blows quite a lot hotter than the drivers vent so even with the climate set to very low the passenger side always blows warm/hot (not ideal at all in the Summer). Audi re-learned all the motors flaps their start and end points which made no difference and they didn't see any error codes associated with any of the heating system. I also ruled out the temp sensors behind the vents by swapping them over and still having hotter air from the passenger side.
I see. With all those steps done, one would lead further toward the blend flap motor. One other variable I am not aware of is if Audi has seen this issue and created a TSB or software update. I would assume not as you have brought it down to them and they only adapted the end stops.
The blend flap was the conclusion I came to, it was a while ago now so I may not be remembering correctly but I tried to get at the blend motor myself and simply couldn't without taking the whole dash out but I'm sure I got a torch down the center heater vents and could see the blend flap operating correctly. Whether what I was looking at was the actual blend flap I can't be sure. Unless anyone knows an easier way of actually getting eyes on the blend flap and/or its motor I'm lost for what to do next.
Our HVAC assembly consists of 5 flap motor / position sensor units. There has been some uploads earlier in the thread but for consistency, I will sum up below:
24 - Recirculation flap motor
25 - Right side temp control flap motor
26 - Left side temp control flap motor
27 - Air distribution flap motor
28 - Defrost flap motor
Number 25 would be the unit you would want to verify for operation (assuming left hand drive for my documents). You may be able to swap 25 and 26 to see if the issue moves but I am uncertain if the connectors are the same from side to side.
Right temp control motor is below the defrost motor:
Left temp control motor location:
What is interesting is all the flap motors have position sensors integrated inside. If they do not get to their desired spot it should set a fault. I would also make sure the flap door moves freely when the motor is removed. Best of luck.
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I have the exact same problem with my 2006 A3 2.0 TDI. Audi has already replaced both flap motors and it does fix it for a bit, but the problem seems to come back after a while. On a lot of forums find to check/replace the position resistance transducer inside the motor housing. They are cheap as chips so will give it a go.
This years warm weather showed me that my aircon needed recharging so I've had that done and now both sides of the car blow cold, I've not yet had the temperature probe in there to actually measure what each side is reading but I will when I remember to do so and post the results here. So maybe the whole warmer air on one side thing is an early sign that the aircon system needs a recharge.
Thought it was worth mentioning anyway.
Thought it was worth mentioning anyway.
I think it is normal..
When I turn AC on mine drivers side is cold but passengers is warm or less cold
When I turn AC on mine drivers side is cold but passengers is warm or less cold
Mine definitely was not normal because in the summer my passenger side roasted whoever was in the passenger seat. Since the AC recharge it's very cool on both sides now.
Or looks like over years it will get blocked one side or vice versa
I had AC re-gassed in 2019 and noticed this year it is warmer on passengers..
Audi A3 AC not working - causes and how to fix it
The air conditioning is a blessing, especially in hot temperatures. Do you still sweat while driving your Audi A3? Your air conditioning system no longer...
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I have the same fault on my A3 (2017). I had it re gassed by Audi but the fault has returned within a month. I have a Audi Used car warranty but annoyed Audi couldn't fix it first time. I have dual climate which is a pain in the BUTT.
I have noticed the drivers vent (right hand drive car) next to the window is always blowing air even when windscreen only is selected.
Audi use cheap plastic clips everywhere, so I have read online, so thanks German engineering. Audi owned by VW and it shows in the parts you don't see.
I will check the motors with VCDS (well worth buying if you own a VW group car) but it looks like aircon gas......again.
I have noticed the drivers vent (right hand drive car) next to the window is always blowing air even when windscreen only is selected.
Audi use cheap plastic clips everywhere, so I have read online, so thanks German engineering. Audi owned by VW and it shows in the parts you don't see.
I will check the motors with VCDS (well worth buying if you own a VW group car) but it looks like aircon gas......again.
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i have the exact same issue with my A3 saloon, had it booked in with a specialist. Who tested all the flaps and motors. They have traced the fault to a fault gas regulation valve which is built into the end of the air con compressor. The air compressor runs fine and put out 10bar but the valve isn’t allowing enough flow through the compressor. They accessed audi TPI’s and supposedly its a common fault with certain compressor used.
But like audi the valve can’t be replaced by itself it requires a whole new compressor. If you have your aircon running and you close the drivers vent the cold air then comes out the next vent along and so on.
But like audi the valve can’t be replaced by itself it requires a whole new compressor. If you have your aircon running and you close the drivers vent the cold air then comes out the next vent along and so on.
Hi
Thanks for that. Audi dealer diagnosed fault under Audi Approved Warranty as corrosion on condenser causing a leak. After consulting a friend who is a registered gas safe engineer I would be wary of putting a sealer in an AC system on a car you want to keep. He pointed out it can block small pipes and parts causing compressors to fail which are about £500.
Also you need to drain the AC system and apply a vacuum to remove all moisture as well as you have to use a known weight of gas or you can over stress the AC system including the compressor.
Glad it worked for you and tempted to try but pushing dealer to pay for repair.
Thanks again for the help.
No worries.
I topped up the system only. So no concern really.
I’d already had the AC service at the dealer (Oct 2019) and it was around early spring in 2020 when I noticed the passenger side wasn’t as cold.
A top up with the can has restored it.
I’ll be getting the system properly emptied then filled later in the year.
I’ve a friend who is an AC engineer and he advised me on topping it up.
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Most AC places add a leak tracer when doing a regas anyway.
If the system has a leak and been left open then the filter drier needs replaced as that absorbs all the moisture.
When doing an aircon regas the vacuum process is done for two reasons and the first is to see if the system will hold a vacuum and the second is so that the system will draw in the new refrigerant in to the system.
As for leak additive only time will tell if it causes any problems.
With a dealer regas or a diy regas the main thing that needs to be checked is the system pressure, yes over charging the system does add extra stress to the compressor but that’s the same whether dealer or diy.
A trained aircon specialist will check pressures to make sure the system is healthy pretty much the same as the diy version.
Usually if the system is over charged then the first thing you notice is that the system doesn’t chill properly because the pressure is too high the compressor cuts in and out .
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If the system has a leak and been left open then the filter drier needs replaced as that absorbs all the moisture.
When doing an aircon regas the vacuum process is done for two reasons and the first is to see if the system will hold a vacuum and the second is so that the system will draw in the new refrigerant in to the system.
As for leak additive only time will tell if it causes any problems.
With a dealer regas or a diy regas the main thing that needs to be checked is the system pressure, yes over charging the system does add extra stress to the compressor but that’s the same whether dealer or diy.
A trained aircon specialist will check pressures to make sure the system is healthy pretty much the same as the diy version.
Usually if the system is over charged then the first thing you notice is that the system doesn’t chill properly because the pressure is too high the compressor cuts in and out .
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And the fans will run at full speed if it’s over filled, the system will shut down also to protect the components.
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Hi
My condenser has a split in it, pics attached. You can see the split on drivers side (UK) if you look into the front grill. Must have had moisture in it that ate its way out.
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Your condenser is more exposed than mine on the RS3.
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Yes but the fault looks like corrosion from inside causing a crack. Rubbish VW group design putting the dryer inside the condenser but Audi do recommend a 2 year AC service which I assume includes dryer replacement and re gas?
