Air con stopped working dealer won't regas it

[amwphotos]

I had my 2014 Octavia Mk3 2.0TDI CR150 serviced at the dealers in Oswestry recently, and asked them to do an air con service at the same time. When I got the car back they said they couldn't do the air con as it wasn't working, so they couldn't re-gas it. I didn't get much more info as it was the Ford service front of house person and they're not as helpful as the Skoda chap.

 

As far as I know if there is an issue, like it's low on gas it would turn itself off. So they can't re-gas it because it's not working, but it might not be working because it needs more gas!

 

 All the fuses are fine, the light still comes on when you press the AC button, I've not got it on eco or turned off in the settings, and there were no real symptoms.

 

Any ideas? Thanks!

[J.R.]

I am guessing that the static pressure was above the threshold to shut down but the high side was not increasing when the A/C was switched on, they were right not to recharge it.

 

An educated guess would be failure of the N280 modulating valve, shear plate failure on the pulley or the central splines stripped on the pulley, all of those would result in no cooling but no fault codes with a correctly charged system.

[ords]

Was it working when you took it to the garage?

[amwphotos]

1 minute ago, ords said:

Was it working when you took it to the garage?

It probably stopped working a week or so before taking it to the garage, I didn't notice anything much happen, only that the car took a little longer to demist than usual.

I needed the car after the service as I was on out of hours call out for work, but they said to take it back when I wanted so they could investigate. I thought I'd investigate the web, and ask on here first to see if it was something I could diagnose or even fix first. I need to do all 4 discs and all the pads when the weather improves too but that's another story!

[SuperbTWM]

Don't want to teach you to suck eggs but are you aware that the air con will not run at around 5C or below.

[amwphotos]

14 minutes ago, SuperbTWM said:

Don't want to teach you to suck eggs but are you aware that the air con will not run at around 5C or below.

My other half has a rapid, and the AC does work below 5'C, it dries the air making it demist much quicker.

[SuperbTWM]

The car will not let the evaporator get near to freezing temperatures as it will ice up causing no air flow at all. So if you have outside air that is just above freezing coming in how can any condensation form if the evaporator is at the same temperature?

 

Its not physically possible. Thats why in cases where the ambient is low you have to use a dessicant style Dehumidifier, for example: Drying out a garage or other outdoor building

Edited 14 February, 2021 by SuperbTWM

[GreenMachine1.6]

My garage could not regas my MKII because it had a very slow leak and it is now illegal to regas a leaking (no matter how slow) system. Is it possible the garage did not give you a full explanation?

[amwphotos]

3 hours ago, SuperbTWM said:

The car will not let the evaporator get near to freezing temperatures as it will ice up causing no air flow at all. So if you have outside air that is just above freezing coming in how can any condensation form if the evaporator is at the same temperature?

 

Its not physically possible. Thats why in cases where the ambient is low you have to use a dessicant style Dehumidifier, for example: Drying out a garage or other outdoor building

Yeah I know how an AC/Heat pump work, usually at low temps, below 0'C there's less moisture in the air anyway, and most dehumidifiers, fridge units, and heat pumps run a defrost cycle to get rid of ice build up. It was a few weeks ago that it started not working and and it was +10 or so then.

The other responses have given some good leads, so I'll see where they take me.

[ords]

If the a/c won't work when it's around freezing point, how do they get on in cold climate countries? How do they stop windows misting up?

[SuperbTWM]

25 minutes ago, ords said:

If the a/c won't work when it's around freezing point, how do they get on in cold climate countries? How do they stop windows misting up?

 Use the blowers and heat or a cloth like everybody did before air con was pretty much standard equipment

 

50 minutes ago, amwphotos said:

Yeah I know how an AC/Heat pump work, usually at low temps, below 0'C there's less moisture in the air anyway, and most dehumidifiers, fridge units, and heat pumps run a defrost cycle to get rid of ice build up. It was a few weeks ago that it started not working and and it was +10 or so then.

The other responses have given some good leads, so I'll see where they take me.

 I’m not suggesting that is your issue, I was kindly making you aware of the fact so you don’t end up chasing your tail while fault finding. 
 

what is strange to me now, is that they didnt do the service. Regardless of the air con working or not, the service should at least consist of removing the old refrigerant and refilling of new refrigerant, therefore making sure it has the correct amount in there. This can be done regardless of whether the air con has any faults.
 

Even if it had a leak, you need to connect the machine up to it and test it under vacuum, or better yet a full pressure test with nitrogen. 
 

 

[J.R.]

Would you service a car that had been dropped off by trailer where the engine had thrown a rod?

 

I am only speculating but customer finds that aircon is not working so asks for it to be serviced, they hook up the guages adnd find that the static pressure is OK so refrigerant charge is sufficient but the high side pressure does not rise when system is operated, = not working, their instruction was to service it and not diagnose the fault.

 

If they had done the service as you advocate and told the customer that there was a fault, even if they could confidently say what it was the customer might swear blind that it was working perfectly before they serviced it.

 

 

[SuperbTWM]

Yes, I see your point, they may not even of had gauges on. Number one on their check list could be ‘make sure air con works before you touch it’ and if it doesn’t they stop the job there. 

[TDIum]

10 hours ago, SuperbTWM said:

 I’m not suggesting that is your issue, I was kindly making you aware of the fact so you don’t end up chasing your tail while fault finding. 
 

 

Also it's useful info for the rest of us. Sometimes even new members use the search function to look for answers to the question they come here to ask. 

[Rodge]

On 14/02/2021 at 22:00, ords said:

If the a/c won't work when it's around freezing point, how do they get on in cold climate countries? How do they stop windows misting up?

Cold air holds less moisture than warm air. The aircon dehumidifies warm wet air by cooling it down so that the moisture condenses out. It then warms it up again to give warm dry air suitable for demisting the windows. If the air is already cold then it doesn't need dehumidifying. Just warming it up will give the warm dry air that you need.

If you don't have aircon and the outside air is warm and wet, then you can still demist your windows by warming the air up some more. This will make it uncomfortably hot inside the car, but it will clear the windows, and is what you had to do in the olden days or if you've bought a cheap car.

[brettikivi]

also: clean windows mist less than dirty ones. Up here you'll see below -15 or so that rear windows ice up on the inside... and thick snow on the outside can mean condensation on the inside if you're using a cabin heater. 

 

Bottom line? humidity is far more of an issue above zero. And moving air will also shift the condensation off, just slower. 

 

 

[ords]

1 hour ago, brettikivi said:

also: clean windows mist less than dirty ones. Up here you'll see below -15 or so that rear windows ice up on the inside... and thick snow on the outside can mean condensation on the inside if you're using a cabin heater. 

 

Bottom line? humidity is far more of an issue above zero. And moving air will also shift the condensation off, just slower. 

 

 

Be interested to know if your a/c shuts down at low temps & if so, do you have problems with misted up windows?  Do you leave it on auto & let it do its thing?

Thanks.

[brettikivi]

My A2 shuts A/C off at 5C.

 

The Octavia shows the LED, but there's no difference on or off at -15. I leave it on Auto, generally at 19 or 20C. But then I also have aux heating and go out of my way to clear large deliveries of snow the night before so I avoid condensation. If there's water on the inside of the screen it will take forever to dry. I do also try to remove the wads of ice from the driver mat occasionally and sometimes will take the car to a heated parking garage to get rid of it all or at least to melt it. 

Auto works really well in the Octavia and A2, and terribly in the S-Cross. There we leave it on 20C and screen / feet and adjust the fan as necessary. 

 

Last week my rental had manual fan - there it was on the screen / feet, full heat, and then turned from 2 - 4 - 3 - 2 on the fan as the car got up to temperature and then back down as it got warmer in the cabin. The A/C "turned on" automatically when I put the fan just to the screen, though I know that cannot work. I suspect it is to stop people asking questions about "Why doesn't my A/C work?" whether it's actually working or not.

 

Awful, that was, too, at -25C with no preheating.

 

 - Bret

[varaderoguy]

16 minutes ago, brettikivi said:

Awful, that was, too, at -25C with no preheating.

 

Feel your pain; however the Octavia's HVAC system is not infaluable.  I also had read not to switch on the AC button during winter, but then did some reading around this subject.  A lot of cars now have pre-heaters in them, so the cooling part of the AC system won't kick in until the ambient temperature gets above a certain threshold (about 6 or 7C) to remove the moisture.  My HVAC system had a challenge the other week when we got down to -15C here in Scotland (so I feel for you in the Arctic Circle).

 

I know that @SashaGracetold me there is a mode which improves the HVAC system when it is hot, but is there a setting that can be changed to take into account the settings for extra cold parts of the world.