Hello to everyone. 
My issue is that AC is not so cold and I’m trying to find if I’m missing something before I go to the dealership or at any shop. 
 

The AC gets cold at some degree but not enough not even close to what it should be I guess. 
The second thing is that it seems that from half of the vents (passenger side) I’m getting  heat instead of cold air on lowest temp setting!!!

 

So I guess I have two problems that I don’t know if they relate to each other. 
 

My troubleshooting steps was:

- checking the cooling fans if they activated when ac is working. 
- Trying to use climatronic on one side each time to confirm that only drivers side is getting cold and the other one does not. 
-  Performed an ac flap reset (multiple times, both with buttons combination and by the use of OBDeleven. 
 

Any help will be appreciated. Thanks. 

Its not unusual to get uneven cooling of the cabin when the air conditioning is not performing well due to low refridgerant. I suspect once you sort out your A/C issue, the issue of the passenger side blowing warm(or ambient) will go away.

 

Can you see what the refridgerant pressure is with OBDeleven? This will give you an indication of the charge level

9 hours ago, SuperbTWM said:

Can you see what the refridgerant pressure is with OBDeleven? This will give you an indication of the charge level

I did not yet checked live data but I will. One more symptom of the issue is when pressing the ac button I hear a small hissing noise like gas travelling through pipes while I’m inside the car. 
I read that this is also an indication of low refrigerant. Can you confirm this? Is this something you also know as a low refrigerant symptom?

If you're hearing a hissing noise then it's time to get the refrigerant topped up.

@VAskodas  If you measure the temperature in the cabin when the AC has been on does it ever get down to 16*oC ?

How much cooler than that do you want the interior?

 

What is the outside / ambient temperature? 

3 hours ago, Ootohere said:

@VAskodas  If you measure the temperature in the cabin when the AC has been on does it ever get down to 16*oC ?

How much cooler than that do you want the interior?

 

What is the outside / ambient temperature? 

I don’t have any measuring device to check the interior temp but it certainly doesn’t get to 16°C. If I could measure the temp even from the vents I don’t think it can push 16°C. The ambient temp certainly plays a role but I don’t think 31,5°C is too high for the AC to struggle in producing cool air. Summer time here in Greece can go up to 39°C but still on my old 2003 fiat stillo the ac can cool the air significantly more than my 2016 Octavia 3. 

It is good when you get AC systems like in your Stillo.  But this is VW Group and not Audi or Porsche.

If the temp is 31*oC or 39*oC outside then the inside is higher and you are trying to cool to over 25*oC less.  It does make a difference.

 

A Digital Fridge Thermostat is about 3 euro.

Then you will know how low a temperature the AC can get the cabin too.

(and tyre temps can get checked as well when doing pressures, maybe when there is a TPMS warning and it is a sticky brake caliper, or a bearing going and a wheel getting hot.)

 

 

Edited 15 July, 20241 yr by Ootohere

A lot of people make that observation about later cars where emissions and fuel consumption requirements together with the change to a supposedly greener refrigerant gas means that they dont have anything like the cooling performance of previous generation vehicles.

 

You said "The AC gets cold at some degree but not enough not even close to what it should be I guess. "

 

Did this vehicle ever cool sufficiently in your ownership?

 

In any case after 9 years there will have been a significant loss of refrigerant through the flexible hose connections to the compressor, a recharge should bring back maximum cooling efficiency, whether that is sufficient for your climate I dont know. My 2016 vehicle does not have the ice cold performance that the previous ones had when working correctly, it was sufficient till I moved to the South West, its been around 30°c in recent weeks and its not really as good as I would like, it hit 43° last year and really struggled.

1 hour ago, J.R. said:

Did this vehicle ever cool sufficiently in your ownership?

Yes it gets cool enough when outside temperatures are below 25°C. As you can tell this is not representative ac efficiency because the temps are already low enough to even turn On the AC. 

 

I want to mention again the other problem that I have were I get warm air coming out from passenger side vents on lowest AC temp settings no matter if I use the SYNC button or individual setting for driver and passenger side. Any thoughts here???
 

16 hours ago, SuperbTWM said:

 

Its not unusual to get uneven cooling of the cabin when the air conditioning is not performing well due to low refridgerant

 

I want to mention that even when I turn off the AC and set only the fans to blow outside air into car I still get warmer air from the passenger side air vents compared to drivers side. How you explain this? Does the air flaps not in proper position and allowing the hot air from the engine to pass through??? 

27 minutes ago, VAskodas said:

 Does the air flaps not in proper position and allowing the hot air from the engine to pass through??? 

A fault code scan will tell if there are any problems with the air mixing and distribution flaps not moving correctly, much better than trying to guess.

Could well be a problem with one of the vent duct temperature sensors, live data or output tests on VCDS will show up any anomolies.

 

From your description of the system working below 25°c it does sound like a low refrigerant charge, once again VCDS used in conjunction with a R134a chart whilst not as good as a manifold set will give you good info, it only measures the high side pressure and the results are incorrect in that it displays absolute and not gauge pressure (might be vice versa) but according to temp and humidity you should see it climbing to the correct pressure when operating, you can only read the low side pressure when AC switched off and the line pressures have equalised, this is of no use, static low side pressure gives a false indication of system charge, you need to see both high and low pressures to decide if the refrigerant level is low or the pump is worn, modulating valve problem etc.

 

The latter is a frequent cause of AC problems on later VAG vehicles and the reason most perfectly functional pumps are needlessly replaced.

50 minutes ago, PetrolDave said:

A fault code scan will tell if there are any problems with the air mixing and distribution flaps not moving correctly, much better than trying to guess.

I already did a scan with OBDeleven and no faults were found. I still need to check live data though for better picture of the fault. At this point theoretically there should be some indication of a fault because of such an obvious difference in temperature coming out the vents.  But no AC fault  stored in vehicle. 
The thing I can’t understand is if there is no faults about the air flaps being in wrong position how on earth I’m getting warm air from passengers side????

5 hours ago, VAskodas said:

I already did a scan with OBDeleven and no faults were found. I still need to check live data though for better picture of the fault. At this point theoretically there should be some indication of a fault because of such an obvious difference in temperature coming out the vents.  But no AC fault  stored in vehicle. 
The thing I can’t understand is if there is no faults about the air flaps being in wrong position how on earth I’m getting warm air from passengers side????

 What J.R is getting at is if there is a sensor reading 10 degrees lower than it should be, the control module won’t know this is a bad reading and may output air significantly hotter than it needs to, to compensate for this. 
 

To self diagnose these issues you need a complete set of data for the car, all the temperature sensors, flap positions etc. maybe some cheap thermometers for comparison. 
 

 

40 minutes ago, SuperbTWM said:

 What J.R is getting at is if there is a sensor reading 10 degrees lower than it should be, the control module won’t know this is a bad reading and may output air significantly hotter than it needs to, to compensate for this. 
 

To self diagnose these issues you need a complete set of data for the car, all the temperature sensors, flap positions etc. maybe some cheap thermometers for comparison. 
 

 

Good point thanks. I will pull the data tomorrow to see if there is a difference. 

Well I checked live data and let me say this is not what I’m getting at day time!! 
Data was taken at nighttime and the AC worked fine. At 31 to 33°C ambient temp I was getting pretty cool air from the AC. There was a minor difference in temperature from right side but later it settled at 2 degrees difference (see photos). 

Im not sure about the refrigerant pressure (8.2 to 11.4 bar) but it was a bit too high of what I saw on YouTube on VW group cars. (Around 6bars). Nvm, again this is not representative data of what I’m getting at day time with higher ambient temperatures. 

I will try live data at day time tomorrow and update here. 

So, I checked the values at daytime and here is what i noticed. 
 

When I set the AC at lowest temperature and the fan speed at maximum it never could produce enough cool air. 
 

But when I reduced the fan speed to half speed I saw a big difference. The readings was nowhere near as before and the air was cool enough not ice cold though!

 

My theory is that due to low refrigerant on AC system it cannot compensate outside hot air to make it cold with the fan blowing on high setting. That’s why when I reduced the blower speed it manages to cool the air. 
Last but not least the pressure of refrigerant seems a bit high at 16 bar(232PSI)!! Does it fit as a symptom of the fault??
 

I’m posting the live data here. 

Edited 17 July, 20241 yr by VAskodas
Adding info about AC pressure.

If the readings are correct, it is blowing cool air, but it always depends on the outer air temperature and fan speed as you noticed. It is able to reduce from 40 to 15C, this looks like thing is working great.  If fan speed is higher, there is less contact of this particular volume of air you measure and you get blowing out warmer - but in general complete volume of air in cabin will be exchanged faster.

 

What I do when it is very hot outside, in the beginning I switch on air recirculation. Later on I switch it back to full auto. These days heat is extreme in our region, I suppose all A/Cs struggle. 

 

1 hour ago, nidza said:

If the readings are correct, it is blowing cool air, but it always depends on the outer air temperature and fan speed as you noticed. It is able to reduce from 40 to 15C, this looks like thing is working great.  If fan speed is higher, there is less contact of this particular volume of air you measure and you get blowing out warmer - but in general complete volume of air in cabin will be exchanged faster.

 

What I do when it is very hot outside, in the beginning I switch on air recirculation. Later on I switch it back to full auto. These days heat is extreme in our region, I suppose all A/Cs struggle. 

 

Well I believe that still there is a problem somewhere in the system because it should be able to cool the air no matter how hot is outside. I’m saying this because I had an old fiat stilo 2003 that doesn’t has this problem. Also at my workplace we have a VW pickup truck AMAROK that doesn’t have this issue of not be able to cool the hot outside air enough at full blast. That’s why I’m insisting. In fact I never experienced this issue on any car I drove. My brother’s Hyundai accent 2004 still can cool down the air enough at any fan speed at any ambient temperature. At least it’s not so obvious to me compared to my Octavia 2016. 
 

Plus, I hear a brief low sound hissing noise in cabin when I turn on the AC so I think this is also an indication of some problem in AC system. 

The key thing is the after evaporator temperature, 5.7°c with an outside air temp of 40°c is excellent, putting the fan on high increased it to 25°c confirming your thoughts that the system does not have enough power to cope with the refrigeration demand on full blower setting.

 

That could indicate a low refrigerant charge but I think that your pressure is correct, the stupid VAG/VCDS set up reports absolute pressure and not gauge pressure so you can deduct 1 bar/15psi from your figures, the figures that you have read on Youtube are almost certainly for an ambient temperature of 20°c.

 

R134a static system pressure (guage pressure not absolute pressure) will rise from 70psi at 20°c to 130psi at 40°c, the high side pressure when system running with an ambient temperature of 40°c will be between 180 and 225psi, that is a figure to cover all vehicles and the variable output VAG type with the modulating valve will be lower than this unless under maximum load, my gauge measurements at 20°c vehicle idling at standstill show the high side pressure rising to 150psi at which point the fans cut in and it drops to 100psi, this falls within the range given on the R134a tables of 100-150psi at 20°c.

 

Are the fans running correctly on your vehicle?

 

Your system will never have enough power to cool your car right down when idling with 40°c ambient temperature, if you look at the figures the air coming out of the vents has dropped by over 25°c at the lower fan setting, aside from the sticking flap mixing hot air to the left vents I say your system is working perfectly, it was designed for average European temperatures probably biased towards the cooler countries.

 

If you want maximum cooling on maximum fan speed you need to drive the car at speed.

 

Most of us have gradually worked these things out, we know high fan speeds at standstill create less cooling, when my car has stood in the sun I leave the windows open initially, use the AC on min temp and fan speed 1, once moving I will switch up to fan speed 2 and close the windows, when the interior temp has dropped enough I will switch to recirculation mode and put the fan on the highest setting.

 

I think you are expecting too much of your system and have a problem with the blending flap for the left hand side.

 

 

Edited 18 July, 20241 yr by J.R.

2 hours ago, J.R. said:

Are the fans running correctly on your vehicle?

The fans are running but on live data I noticed that they won’t go above 38-40% speed. Never seen the speed close to 100%. 
 

The AC system has the new type of refrigerant (HOF 1234 yf) or R1234yf and don’t know if a slight deviation of refrigerant capacity is playing a major factor or not (in case of a leak). 
 

And yes I do expect from AC to be able to handle summertime temperatures at full blast cuz it’s been for me like this forever and can’t get it when I have newer/modern/in theory better car and cannot have the cooling that I I had with older ones. It’s a shame for me. 
 

I think the last step for me is to visit a shop for ac recharge and address the air flaps being possibly in wrong position. 
 

Thanks for the input. 

Looks like too much expectations. There are cars with a/c sharp as razor, but not in this price segment. 
 

Turn on recirculation when it is 40C outside. 

Refill refrigerant,  then troubleshoot if necessary.

 

May not be any remaining problem to solve after that.

 

Oh, just one other thing, does your engine coolant expansion tank say "Mit silikat" on the outside?

I'm sure I've read about asymmetric heating/cooling when heater matrix gets clogged up. (Maybe only heating, now I think on it).

 

Edited 18 July, 20241 yr by Breezy_Pete

55 minutes ago, nidza said:

Turn on recirculation when it is 40C outside. 

When outside temperature is 40°C inside the car is at least 42°C I measured so no gain from there. 
 

As J.R stated in his comment it’s better to cool down interior temperature gradually and then use the recirculation mode because it will be already lower than outside air. 
 

Either way, I still think my expectations are reasonable because it is almost certain that the system has some sort of irregularity so when I sort it out any gain at this point will be beneficial. 

43 minutes ago, Breezy_Pete said:

(Maybe only heating, now I think on it).

You are right it is only for the engine cooling and heating the interior of the car. Different system different circuit. 
 

But to answer you question about mit silikat, no it doesn’t have this bag. I think on late 2013 and up they removed this expansion tank bag.