7 minutes ago, VAskodas said:

Different system different circuit

Yes, but if the various control flaps are mis-directing the air leaving the evaporator, it could be involved in causing asymmetric temperatures, if temperature is uneven across its width, and cooled air is wrongly being sent through.

28 minutes ago, VAskodas said:

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. 

Didn’t get it from your original explanation.

 

Does it cool down after 5 minutes of working, when driving? 
 

I use recirculation immediately, in a minute already is getting bearable in the car and 2 3 minutes later quite fine. 

 

 

1 hour ago, Breezy_Pete said:

Yes, but if the various control flaps are mis-directing the air leaving the evaporator, it could be involved in causing asymmetric temperatures, if temperature is uneven across its width, and cooled air is wrongly being sent through.

That’s right. Indeed if the air flaps are in wrong position and mixing the cooled air and the air from the heater then it can cause asymmetric temps but this has nothing to do with heater core being clogged or not. In fact if it was clogged I wouldn’t have this difference though. 😁

 

Edited 18 July, 20241 yr by VAskodas

If it was clogged unevenly so that one side was hotter than the other you might.

But I agree, it's probably not relevant if you have no silikat 'pollution'.

13 minutes ago, nidza said:

Does it cool down after 5 minutes of working, when driving? 

It does cool down a little bit after around 10 min so after that putting it on recirculation mode has a meaning. 

49 minutes ago, Breezy_Pete said:

If it was clogged unevenly so that one side was hotter than the other you might.

But I agree, it's probably not relevant if you have no silikat 'pollution'.

I want to mention that not only the engine cooling expansion tank could have a silikat bag but the AC system also has a dryer that contains pretty much the same material inside it in form of small balls, so maybe you are right about something being clogged up. 

Edited 18 July, 20241 yr by VAskodas
Adding screenshot

You have a mixing flap problem (or duct sensor) which is mixing hot air with the cold(er) air from the evaporator, that will not be helping.

 

Now I know you have the new "greener" and far less efficient cooling gas which is always combined with an underpowered AC system (to minimise the amount of greenhouse gas) I know that your expectations that the system should work as well as the previous R134a (which aint up to much itself compared to R410 and freon) are way off the mark, you are comparing apples with tonsils.

 

It will get a little better when the mixing flap problem is resolved, it might get a little better if recharged but with 40° ambient temperatures you are going to have to learn to work with its limitations and not push so much airflow through when at idle and when moving off after getting into the vehicle that has been stood in the sun, you need to consider it to not have AC, to choose shaded areas to park, use sunblinds, leave windows open etc.

 

You should see the condensor fans commanded at more than 38% when at idle using the AC to the max (high ambient temp, high blower speed, min temp selected, it may take a couple of minutes to ramp up to it, I have no knowledge of the new gas and its operating characteristics other than everyone unfortunate to have an AC system with it considers it barely capable in frigid UK summer temperatures.

Re recirculation mode.

 

I now live in a very hot place compared to before, it was 33° today and the temperature sensors that saw any sunlight were over 50°c.

 

I never manage to find a shaded spot, other wiser more experienced people have always bagged them, I keep the windows closed for security so when I get in the parked vehicle even if it has been just 10 minutes in a shop then the inside temp is way hotter than the outside ambient.

 

First thing I do is open the windows to let some heat out, start the car, AC on full but not recirc, the outside air is far cooler, today would have been at least 17°c cooler, I drive off as quickly as I can, I can close the windows very quickly and then judge when the time will be right to switch to recirculated air, it will usually be between 3 and 5 minutes, the hotter the day, the longer the car has been exposed to direct sunlight the longer will be the delay before I can switch to recirc.

 

Once I feel comfortable inside I switch back to ambient air, during a journey it might get warmer inside, and I can see from the dash that the ambient air temp has increased, often in slow traffic, if I am uncomfortable I will switch back to recirculated air.

 

This is all with an R134a system in hot weather, I would need to be even more obsessive with the new chocolate teapot refrigerant gas.

8 hours ago, J.R. said:

You have a mixing flap problem (or duct sensor) which is mixing hot air with the cold(er) air from the evaporator, that will not be helping.

 

Now I know you have the new "greener" and far less efficient cooling gas which is always combined with an underpowered AC system (to minimise the amount of greenhouse gas) I know that your expectations that the system should work as well as the previous R134a (which aint up to much itself compared to R410 and freon) are way off the mark, you are comparing apples with tonsils.

 

It will get a little better when the mixing flap problem is resolved, it might get a little better if recharged but with 40° ambient temperatures you are going to have to learn to work with its limitations and not push so much airflow through when at idle and when moving off after getting into the vehicle that has been stood in the sun, you need to consider it to not have AC, to choose shaded areas to park, use sunblinds, leave windows open etc.

 

You should see the condensor fans commanded at more than 38% when at idle using the AC to the max (high ambient temp, high blower speed, min temp selected, it may take a couple of minutes to ramp up to it, I have no knowledge of the new gas and its operating characteristics other than everyone unfortunate to have an AC system with it considers it barely capable in frigid UK summer temperatures.

Thanks for the input. You are right. Eventually I have to deal with this if these facts that cannot be changed. One more thing though, do you know about the ac control valve? It seems like it’s responsible for the flow of refrigerant into the system and looks like most of the time this fails and all the symptoms we discussed here is probably from this. 

https://www.aliexpress.us/item/1005005443109461.html?spm=a2g0o.productlist.main.9.4444xxplxxpl3a&algo_pvid=1ed325cc-4487-4458-832d-a92012d19aab&algo_exp_id=1ed325cc-4487-4458-832d-a92012d19aab-4&pdp_npi=4%40dis!USD!13.13!6.57!!!95.05!47.52!%40210385db17213785601194965e9c45!12000033102304438!sea!SRB!709016433!&curPageLogUid=WNMVGqB0YEYQ&utparam-url=scene%3Asearch|query_from%3A

 

Can you measure temperature of blowing air out of each vent? I can do this on mine to compare? In Belgrade is near 40 ever day past 10 days (after we returned from Greece :D). 

2 hours ago, VAskodas said:

do you know about the ac control valve? It seems like it’s responsible for the flow of refrigerant into the system and looks like most of the time this fails and all the symptoms we discussed here is probably from this. 

 

Yes, all too familiar with it!

 

It's failure mode is it sticks or fails and stops working = no refrigeration, - not your case.

 

With your high side pressure the system is definitely pumping, without putting a manifold set on it and seeing the ralationship between high and low side we cant deduce any more like a partial blockage, freezing of the gas at the evaporator nozzle etc.

 

A regas is very expensive for the new gas and many garages are not equipped for it, I think you have already invested in VCDS, you should consider buying an AC manifold test set.

In the set up menu, have you got it on the strongest setting?

12 minutes ago, ords said:

In the set up menu, have you got it on the strongest setting?

 

I was just about to put this!

 

I know some cars don't always have this option but in driver modes I can set my air con to economy or normal.

 

 

16 minutes ago, ords said:

In the set up menu, have you got it on the strongest setting?

I didn’t noticed any other option in AC menu other that SYNC, AUTO/MANUAL, and some monitoring figures that change when you adjust each option. 
 

I don’t remember if the little gear/setting button does or has some extra options….i will check it. 

Yes if you have a drive mode button and put it onto individual you can set air con to normal or eco. Also the plug A on the condenser can be faulty from factory so there is and update for plug and seals.

2 minutes ago, Blue8793841 said:

Yes if you have a drive mode button and put it onto individual you can set air con to normal or eco. Also the plug A on the condenser can be faulty from factory so there is and update for plug and seals.

Nice. Thanks for the info. Will check will check tonight. 

That would be a very good resolution!

 

You still need to attend to the blending of hot air to the left side problem though.

Indeed it has that option to individually set some options and yes it was set to ECO. But I do not believe that this was the cause of my issue because I did not use that mode. I used only normal and sometimes the sport mode. All measurements that I checked previously was while in normal mode and cannot really tell if the ac setting wasn’t or was on eco mode. In fact now I’m thinking that probably when used ECO mode the ac is set to ECO and when used NORMAL OR SPORT MODE the ac setting is on normal.  So that’s that. 
 

But it still cannot handle the 33°C ambient temperature in lowest temp setting and full blast. The only solution for now is to use the recirculating air when the inside temperature is lower than external. 

Edited 19 July, 20241 yr by VAskodas

24 minutes ago, J.R. said:

That would be a very good resolution!

 

You still need to attend to the blending of hot air to the left side problem though.

Yes I agree. I noticed something else tonight. While I was set the air vents to  the footwell air flaps I was getting air also from the left and right side vents although on the infotainment screen menu the graphic representation of the airflow showed that the air is going only to footwell vents!! So it must be the air flap mixing problem here for sure. 

Edited 19 July, 20241 yr by VAskodas

On 19/07/2024 at 22:24, VAskodas said:

Yes I agree. I noticed something else tonight. While I was set the air vents to  the footwell air flaps I was getting air also from the left and right side vents although on the infotainment screen menu the graphic representation of the airflow showed that the air is going only to footwell vents!! So it must be the air flap mixing problem here for sure. 

 

I'm not sure if an element of that is normal, I know for sure when I have the windscreen only selected I also get *some* air from the vents at each side of the car, presumably to aid in keeping the side windows mist free in winter. Never tried to see if there is any when the footwell is selected though

 

THe belnding flap is a different flap to what diverts the air to each section so if it is abnormal it will not be the blending flap at fault I don't think.

Edited 22 July, 20241 yr by SuperbTWM

Just FYI, bear in mind this manual is for a Passat but it gives a good reference for expected temperatures at a given ambient:

Edited 22 July, 20241 yr by SuperbTWM

4 minutes ago, SuperbTWM said:

 

I'm not sure if an element of that is normal, I know for sure when I have the windscreen only selected I also get *some* air from the vents at each side of the car, presumably to aid in keeping the side windows mist free in winter. Never tried to see if there is any when the footwell is selected though

Maybe it is true but the thing that confuses me is that on the ac menu screen it shows you the air flow vents that you have selected and when you use let’s say the front vent setting it shows you the side and the front vents being activated and when you use the footwell setting it shows only the according vents but not the side ones. So either it’s it a default set up for side vents being active all the time or something is wrong here. 

50 minutes ago, VAskodas said:

Maybe it is true but the thing that confuses me is that on the ac menu screen it shows you the air flow vents that you have selected and when you use let’s say the front vent setting it shows you the side and the front vents being activated and when you use the footwell setting it shows only the according vents but not the side ones. So either it’s it a default set up for side vents being active all the time or something is wrong here. 

Just been to my car and can confirm air is ditributed to both side vents whatever the setting.

 

If it showed air to these vents all the time on the screen people would think there was something wrong with the selection so you can't please everyone either way I don't think.

17 minutes ago, SuperbTWM said:

Just been to my car and can confirm air is ditributed to both side vents whatever the setting.

 

If it showed air to these vents all the time on the screen people would think there was something wrong with the selection so you can't please everyone either way I don't think.

Ok. That’s good. So no issues there.  
It is helpful to know that this is how it should be. Moving on then…😁

On 18/07/2024 at 12:18, J.R. said:

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.

 

 

How much difference could a clogged condenser cause? Flies and dirt etc? Could it be only that which is the case of poor cooling?