Air Con: Has the heat killed it?

[TomTheTyke]

Afternoon all,

Bought my car in September last year. At that time, I had the 'whooshing' noise when the air con was running, suggesting it needed re-gassing. Had this done, bloke said it was very low, but it is a 2001 car and no evidence of air con work anywhere in the history.

Worked pretty much fine since then as far as I have noticed, got cool fairly quick and no strange noises.

Got in the car today after work, dash displaying 37.5C. Fans blowing on high as they should with the system set for 20C, but after 5 or 10 minutes had not blown cold air.

Tried switching on and off a few times (while sweating more and more!), but same result. Almost seems to get cold a bit then revert to blowing hot. Think compressor is running as the car seemed a bit down on power, and revs fluctuated slightly when stationary.

Got home and looked under the bonnet, Low air con pipe seemed slightly cooler than environment but not cold and a 'clicking' noise every 3 or 4 seconds from the compressor area.

Radiator fan did come on once air con was engaged as well.

Surely it's not coincidental that it's gone from working to nothing on such a hot day, but don't know enough about air con to know where to start. Suppose first step is to try it once the surroundings and engine have cooled.

[Nantwich 75]

I do wonder if the air con condenser needs replacing?

[TomTheTyke]

Originally Posted by Nantwich 75

I do wonder if the air con condenser needs replacing?

Maybe, would there be any way to test this theory? Visual inspection? Instinct is this would be a more gradual failure but as I say, limited knowledge.

[JefferiesFarnol]

I've just come to the bottom of my air conditioning problems after a lot of back and forth. The first thing I was advised to do was check the cooling fan at the front of the engine was working at both speeds as it should run whenever the a/c is on, it sounds like yours is working.

My garage then found a leak in the condenser which was replaced but it then stopped after about two days. I finally called out a mobile A/C man who couldn't find a leak with a pressure test but filled the system with the UV leak detecting dye and two days later there was no A/C again. I had a look with a UV light and I have a pinhole in one pipe but the compressor is just belching out the gas and is covered with dye.

We also found that when it was being charged, the pipes weren't quite as cold as they should have been and the compressor didn't build the pressure up as quickly as it might have. I think what can happen if the compressor is failing is that it only drives out the gas when it's running, which is why it seems like there isn't a leak at first.

I'm absolutely no expert but this is my situation and maybe it can help. it seems your fan is working so if you can get someone to recharge the a/c with some of the dye, you'll be able to see a leak and if your compressor is leaking like mine, you should see this under a UV light.

[TomTheTyke]

Originally Posted by JefferiesFarnol

Stuff .

Thanks very much. I think you may be right in as much as it’s not obvious so may well require professional input.

[JefferiesFarnol]

Originally Posted by TomTheTyke

Thanks very much. I think you may be right in as much as it’s not obvious so may well require professional input.

I didn't think mine had lost its charge for a while but I think in cases like this, all roads lead to a loss of gas. It sounds like yours won't stop again as quickly as mine did so if you were to get it recharged, then if it ever does stop again you'll have the benefit of the dye to show you where it's coming from.

[suzublu]

As I've said before, these cars are now around 20 years old, the condenser takes a lot of punishment being front facing, so that would be my first port of call

Sent from my SM-A326B using Tapatalk

[The Rovering Member]

My condenser & compressor were both replaced with new items by Trikey in 2020. He wasn't kitted out to regas the system so l had it done shortly after by a local garage. I meant to get a mobile specialist out but took the quick option as we were going on holiday in the car. The system worked pretty well & still does as we found out yesterday on a trip to the in-laws in Little Clacton.
However though it does blow cold l do have a feeling that it could be better. It takes a little while to get the temperature down but the temperature drop is rather localised to the dashboard vents & doesn't really seem to spread throughout the cabin. I know it's pretty warm at the moment but l am still planning to get a specialist to visit & go through the system properly.

[Arctic]

Hi Thomas.
Do the demist test first to see if your fan is working continually on low speed if not then that could be your problem, also check that there is enough gas in the system, and the condenser is ok, the fans, on these old cars will be put to the test over the next few weeks.


Nano fans.
1

[TomTheTyke]

Update as of 11.15pm. Popped out to the car just before bed, gave it a try now everything had ‘cooled down.’

We had cold air again almost straight away.

Not sure if this is possible but there is no shade in the car park at work so car was stood all day in direct sun, then engine running adding to that. Could it be a symptom of tired compressor / condenser just not being able work efficiently enough in those temperatures?

Again my lack of AC knowledge is showing, no such issues in the TF!

Edit to reply Arctic: thanks for the info, I will check the demist but when I just turned the AC on auto earlier, the fan came on, but would that be testing the right speed? Condenser looks OK in terms of major damage but presumably bumper off to have a proper inspection?