Im hoping its just low on gas, but what worries me is that it was cooling exceptionally well about a month ago. We bought the car used with 90k miles on the clock in 2018, now has 110k miles on there. Could be that it has never had a regas.
But if it was coming out very cold before, I would have expected a gradual decline in cooling not a sudden stop?
I'm tempted to try this myself (only to learn), where would I find the low pressure valve on this car? I will get it checked probably but just want to see under the bonnet.
Thanks.
The car can actually cool better when gas is getting low ( until the point where pressure switch 'says no'), low gas causes some systems to get too cold and ice up - for the aircon to work properly and not freeze up the air blowing into cabin needs to be about 7deg C - there is a balance in the system about how fast the gas can expand ( that is the cooling bit ) and the correct compression and expansion 'cycle' physics depends on the correct weight / volume of gass in the system. Just like your bicycle pump used to get hot when you blew tyres up and the valve got colder when you let air back out is the basis of aircon, but using much more efficient gas instead of air.
below is a quote from an airconditioner fault finding article
4) Low refrigerant
What Causes Aircon Coils To Freeze Up?
If your air conditioning unit has a low refrigerant then it can also freeze up. This is because when the refrigerant level drops, there will be less pressure which will make the flashing happen early than expected.
This early flashing process can create enough cold air which will condense into moisture on the coils and then immediately freeze up. If the flashing continues, more ice will continue to build up such that it will even creep up to the copper pipes.
What Causes Aircon Coils To Freeze Up? – Conclusion
Having a low refrigerant is a sign that your aircon is experiencing some leakages. Therefore it is good that you sought it out in time to prevent further damages.
If there are small issues with your aircon system and you leave them unattended for a long period they can make the coils to freeze. Therefore, you must conduct routine maintenance to solve the issues early enough before they worsen.
Some issues can damage your aircon completely such that you may be required to buy a new one. However, if you check the issues highlighted above in time, you will minimize the chances of having frozen aircon coils.
The car must have had gas added at some point, even a car that uses aircon regularly will lose about 10% a year, that means your will have lost 140% of the original gas...... during lockdown with a lot of cars hardly getting used the gas would have been lost at much more than the rate when system is used often, as the seals get less supple. The best advice is still to get a £50 regass and then look for problems if it still does not work, I have never seen on here that a pressure switch has failed - and only a very, very few compressor fails ( the Jazz compressor is a scroll type, and very robust ). The pressure switch is most probably buried deep in the system and it may cost as much or more to get it checked as a regass. Other suspects are the aircon relay and the clutch solenoid - but 99% of the time when system does not kick in it is just low gas......