A/C problem - left side cooling, right side heating

[betmen]

I have a problem with the cooling in the car, the left side is cooling, and the right side is not, it even heats up a bit.
I was in the service because I thought there was no gas, but they told me that the air conditioning was working well and that the pressure and temperature in the pipes was good, and that the air deflector was probably not working well.
I checked all the air deflection motors and they all work, I also checked all the temperature sensors, 4 pieces, took them out and tested them and they are all OK.
I scanned the climate with VCDS and there are no errors.
I measured the temperatures when the A / C is running and it can be seen that there is a high temperature to the right front and behind the evaporator.

Does anyone know what the value of the correct sensor after the evaporator is? This is suspicious to me because the measured temperature is 32.3 ° C behind the evaporator and in the right cooling opening.

 

Does anyone know what the problem might be?

 

[J.R.]

You need to look at the measuring blocks directly beneath the ones that you have ticked, those for the right temperature flaps, I suspect it is stuck in the hot position.

 

AFAIK there is only one post evaporator temperature sensor which whould be less than your value if the left hand side is cooling.

[ords]

This may be of some help.

 

[betmen]

1 hour ago, ords said:

This may be of some help.

 

No help from this hread, this is when heating is not working, nothing to do with A/C.

[J.R.]

And I think it gives misleading information (no doubt where the person swallowed the BS of the repairing garage) that the the car has a dual heater matrix half for the drivers side the other for the passengers, to my knowledge and having removed mine its one matrix and the control valves blend heated and coooled air to get the desired left & right side temperatures.

 

Happy to be proved wrong but once something is written, accepted and oft repeated its very hard to disabuse people of the notion.

[betmen]

3 hours ago, J.R. said:

You need to look at the measuring blocks directly beneath the ones that you have ticked, those for the right temperature flaps, I suspect it is stuck in the hot position.

 

AFAIK there is only one post evaporator temperature sensor which whould be less than your value if the left hand side is cooling.

I recorded this video and you can see that motor for the right flaps is working and the gears are turning, because of that I think that this flap is working,

Only if they don't spin in idle and the fault is inside the evaporator housing but I think that's unlikely.

Here is the link for video it is to big to post it here:

https://photos.app.goo.gl/q2f1cRUi2fu7n11o8

 

If I will have time I will measure blocks for the right temperature flaps, I am going avay to the weekend.

 

[Ecomatt]

Have you actually had the air con serviced at all because these issues can be caused by low refrigerant. Or did the garage check the levels only?

Edited 23 July, 2021 by Ecomatt

[betmen]

6 minutes ago, Ecomatt said:

Have you actually had the air con serviced at all because these issues can be caused by low refrigerant. Or did the garage check the levels only?

I wrote that in the first post I was in service and they said that everything is fine with the cooling system and that the problem is probably in the air control wings, I checked all that I can and everything is OK, now I don't have idea what can be wrong.

[varaderoguy]

4 minutes ago, betmen said:

they said that everything is fine with the cooling system

Arh - that old chestnut! Everything looks fine - a usual catch-all to say that they probably don't have the equipment to check the HVAC system properly or the levels of the R1234y coolant.

Typically, the HVAC system need servicing every 2 to 3 years - if it hasn't been done (or you don't have a record of it being done) then get the system serviced first and try again.

[betmen]

6 minutes ago, varaderoguy said:

Arh - that old chestnut! Everything looks fine - a usual catch-all to say that they probably don't have the equipment to check the HVAC system properly or the levels of the R1234y coolant.

Typically, the HVAC system need servicing every 2 to 3 years - if it hasn't been done (or you don't have a record of it being done) then get the system serviced first and try again.

They connect car`s A/C lines to the some device for I think gas filling and extraction and told me that with A/C sistem is everithing OK, good presure and good working temperature.

Edited 23 July, 2021 by betmen
error

[J.R.]

2 hours ago, betmen said:

I recorded this video and you can see that motor for the right flaps is working and the gears are turning, because of that I think that this flap is working,

Only if they don't spin in idle and the fault is inside the evaporator housing but I think that's unlikely.

Here is the link for video it is to big to post it here:

https://photos.app.goo.gl/q2f1cRUi2fu7n11o8

 

If I will have time I will measure blocks for the right temperature flaps, I am going avay to the weekend.

 

I cant open the video without jumping through hoops for Google, they already badger me on my phone to give them my date of birth, - yeah right, they can whistle for that.

 

Its possible that the gears are turning but the shaft not, the measuring blocks should tell you what is going on, maybe try changing the set temp to something very different and use the same setting for the passenger one, maybe maximum heat and see if they both have the same temperature, then go down in steps of a few degrees, that should tell you something without the work up of VCDS.

 

I cant accept the assertions that this problem can be caused by low refrigerant, I would expect that to affect both sides equally unless it favors the passenger.

 

What temp is coming out of the rear vents? I think they are slaved to the passenger setting.

[betmen]

On 23/07/2021 at 17:08, betmen said:

Today I made some measurements, table is in the attachment and in this post,

I think that 

Right temp.flap-actual value is not responding like it should. what can cause it, please give me some comments. ADJUSTED TEMPERATURE LO 22,5 25 HI LO HI LO AUTO 24 AUTO HI AUTO Left front temperature 17 17 26,3 45,3 18,7 35,7 23 23 24,3 Right front temperature 27 27,3 27,3 38,3 28,3 42,7 32 32,3 34 Left temp.flap-actual value 0,00% 10% 55% 100%           Left temp.flap-actual value 19 41 136 231           Left temp.flap-specified value 14 42 136 236           Left temp.flap-cold stop 19 19 19 19           Left temp.flap-warm stop 231 231 231 231           Right temp.flap-actual value 0,00% 0,00% 10% 99,50%           Right temp.flap-actual value 20 20 42 231           Right temp.flap-specified value 15 15 44 237           Right temp.flap-cold stop 20 20 20 20           Right temp.flap-warm stop 232 232 232 232           Front air distribution flap actual         1% 49% 0,50% 12,50% 49% Front air distribution flap actual         22 126 21 47 126 Front air distribution flap specified       14 127 14 46 127 Front air distribution flap air outlet stop       236 236 236 236 236 Front air distribution flap footwell air outlet stop     19 19 19 19 19 Defrost flap actual         0% 55,50% 100% 79% 55% Defrost flap actual         10 131 228 183 130 Defrost flap specified         5 129 233 228 129 Defrost flap stop open         228 228 228 10 228 Defrost flap stop close         10 10 10   10                     Refregerant pressure 8,0 bar                 Compressor current actual 0,815 A                 Compressor current specified 0,820 A                 Compressor current spdecified 800/min               Compressor current load 5,8 Nm

 

AC measurements.xlsx

[betmen]

I went to the holiday few days ago and it was very hot, about 35C outside and about 40 inside.

I closed passengers vents but this did`t help. I suspect that evaporetor sensor is not good, anybody knows what the originals sensor worth in ohms should be?

On the pics is the actual sensor.

Quote

 

 

[betmen]

Here is some more measurements, any advice anybody;

 

ON/OFF	ALL OFF	VENT OFF	VENT ON	VENT ON	VENT ON
A/C		A/C OFF	A/C ON	A/C OFF	A/C ON
SET TEMPERATURE		LO	LO	LO	LO
PARKED/DRIVING	PARKED	PARKED	PARKED	DRIVING	DRIVING
Refrigerant pressure	7 bar	7 bar	10,6 bar	6,6 bar	7,2 bar
Compressor shut off requirement	A/C off or fan control switch in 0 position	A/C button off	compressor active, no shut off condition is present	A/C button off	compressor active, no shut off condition is present
Compressor current actual value	0,00A	0,00A	0,80 A	0,00A	0,745 A
Compressor current specified value	0,00A	0,00A	0,82 A	0,00A	0,820 A
Compressor load	0,5 Nm	0,5 Nm	8,5 Nm	0,5 Nm	2,9 Nm
Coolant fan activation actual value	10,00%	10,00%	32,00%	10,00%	10,00%
Coolant fan activation specified value	0,00%	0,00%	28,40%	0,00%	0,00%
Outside air temperature	31,5 C	33,5 C	34,0 C	27,5 C	27,0 C
Outside air temperature internally calculated	29,5 C	29,5 C	29,5 C	27,5 C	26,5 C
Left front temperature	35,0 C	36,3 C	31,3 C	34,7 C	28,3 C
Right front temperature	32,3 C	36,0 C	36,0 C	35,7 C	35,0 C
Temperature after evaporator	37,7 C	35,0 C	34,3 C	33,3 C	34,0 C

[MarsnW]

Digging up old threads, but I've just had this exact issue (relatively cold air from driver vents, hot/warm air from passengers) and had it fixed so may save somebody the time if they have the same symptoms. All I needed to do was to get refrigerant refilled.

 

There were no error codes associated with the AC, however when looking at system parameters using OBD, I could tell it wasn't efficient enough - evaporator temp was at 12C and the refrigerant pressure was at 9 bar. After recharging it, both sides started blowing cold air and the evap temp dropped to single digits.

[Snapper1725]

On 03/07/2022 at 22:35, MarsnW said:

Digging up old threads, but I've just had this exact issue (relatively cold air from driver vents, hot/warm air from passengers) and had it fixed so may save somebody the time if they have the same symptoms. All I needed to do was to get refrigerant refilled.

 

There were no error codes associated with the AC, however when looking at system parameters using OBD, I could tell it wasn't efficient enough - evaporator temp was at 12C and the refrigerant pressure was at 9 bar. After recharging it, both sides started blowing cold air and the evap temp dropped to single digits.

Hi 

I’ve a temperature fault between passenger/drivers side on a 2013 Superb.

spent ages stripping/checking things etc and all seems ok with the motors/sensors ( even put two new sensors in which didn’t make any difference) 

You say you got the refrigerant refilled and all was ok. 
So will this effect the temperature if using heaters normally without aircon.

My heads battered with this fault 🙄

Showing no faults on Obdeleven apart from a temp difference on live reading