A/C not blowing cold but refrigerant is full?

I've just got back from a a free Air Con test at Halfords as I assumed I was low on gas with the AC not blowing cold and it being around 5 years since I last had it charged. They put their gauge on it and it is reading full in the green on their testers gauge. I have just checked the compressor to see if the engine revs drop when I push the AC button and it does drop a little and I get a noise in the cabin like the AC is kicking in, its makes a hiss sound but not in a leaking kind of way, I know it did this before but I'm unsure how loud the hiss was previously. I did have an issue recently where my temp sender was playing up but this is now fixed and the correct temperature is showing on the dash. The guy at Halfords says it could be the condenser but unless it is leaking I can't see why it would be that, could the drier be an issue, any other ideas what could be causing this?

It sounds like the levels are not exact or the flaps behind the dash have lost their foam. ATS kept telling me my levels were fine, but I knew they weren't as the climate sometimes made a whistle and also there was more noise from behind the dash when the air con was engaged. I got a local climate specialist out and he said these need to be spot on. My car had gas in the system, but it was right at the bottom of range, so he drew it all out and refilled it to be bang in the middle and everything was good. Now really hard to hear the difference between climate on or off and it is icy cold. The foam on the flaps behind the dash can disintegrate too, so it doesn't direct hot and cold properly, you are just left with a mix of both all the time. Is every vent the same temperature?

Have you looked if the clutch has actually engaged on the compressor - with the aircon switched on the centre of the pulley should be spinning. By what you've said it sounds like it is. Check the long low pressure pipe that runs down the length of the car is getting cold, also if the high pressure pipe is warm or getting hot. You at least then know that the system is operating correctly and the fault lives within the HVAC system. If it's the aircon side of the system and your compressor is engaged then I'd guess that you possibly have a sticky expansion valve.

Download this file and scroll to section 8 for A/C info ... https://drive.google.com/file/d/1ZkV335ignXS5tePDu9se9nBh1nbpmEQ0/view?usp=sharing Start with the above posts before this though .. If the compressor clutch is spinning , which if you have a hissing noise would indicate that it is then it's possibly a sensor fault . 4 sensors in total , to test the interior ones .. switch it to lo setting .. is the a/c working .. not applicable here but for a cold car you would switch to Hi setting .. it should go full heat then . This basically bypasses the X2 sensors in the car .. one is cabin temp which is behind the round vent n/s/f but the passengers vent .. the other is the outlet temp sensor .. drivers footwell from memory . Assuming you have no a/c working at all then the inlet temp sensor might be the issue .. you really need a tester on the car to look at all these values . The inlet sensor .. if it is giving a false reading .. it can stop the a/c from working .. basically the a/c will be switched off if this sensors reports a temp of 2.5 degrees or lower . Pressure sensor might be faulty .. you'll need a tester for that to look at the value its reporting .. With what you do with these cars then i would humbly suggest you keep an eye out for a piwis 2 .. as we are almost into the 4 these days i've been told these are not that desirable anymore and should be cheapish .. That's what our computer guy said anyways . Going back to hard faults .. compressor might be spinning but that's no guarantee its working , expansion valve as mentioned .. rare but possible . Crushed pipe o/s . Any of these are checked with an a/c machine and the car running .. we look at the pressures .. HP should be above 10 bar , LP and around 2 ... if both similar at say 4 then its not working . Did they say what the pressures were when they checked the car ? that would be useful to know . Last thing .. a hissing noise does indicate a low gas pressure .

Nice to see you back posting deMort :thumbs:

So sorry .. i'll be around when i can .. i can always be reached via email if really needed .. But the poster MUST report back here .. bosses orders Other things in life i'm afraid but i'll do my best . Btw .. download that file .. i wont keep it up for too long .

I have had good experiences with the mobile A/C specialists, this is what they do all day and they are very knowledgeable. They will never have the intimate knowledge of Porsche which De Mort kindly provides but they can sort the essentials OK.

I had a quick text chat with a local AC engineer last night and he feels confident that it is low on gas after I gave him the symptoms, I have used him before and he knows his stuff? I have booked in with him next week to hopefully get it sorted. If it does turn out to be something other than low gas I'll work my way through the above tips from you guys. I'm still unsure why the Halfords tester showed good gas pressure and in the green on the gauge but we are talking about Halfords I guess?

It may not be low gas to be fair .. but the hissing noise and lack of a/c kinda points towards it . A lot of checks are done with the vehicle running .. at that point it's pretty obvious its down on gas .. the only other way is remove and measure .. a/c on these .. it will still work just about down to approx 300 grams out of 900 . See how you get on with that a/c guy .. anyone that specialises in this area will soon nail it down . Btw .. download that file please as i'll be taking it down soon .

I used Halfords Autocentre once. They also told me an old Jag S Type was fine on gas levels. After doing all the other checks, half a can of EZ-Chill soon got it cold again. The industry is full of idiots nowadays.

I probably should have known better but it was free, 5 minutes away and it was a Sunday, probably caused me more issues than it solved, basically it was tested by a shop keeper :dont know:

I had my regas done around a month ago and all was fine and super cold which I needed as I was over in the Alps a few weeks ago and it was 26 degrees, I had parked the car for a couple of week after getting home and when I decided to go for a drive in mid 20 degree heat a week or so ago I soon realised my AC wasn't blowing cold any longer. I hadn't touched the car recently but decided to have a look today, as I have an upcoming MOT and I wanted to change some exhaust clamps and the rose joints on my rear toe arms beforehand. I have dye in my AC system and I also bought a UV torch. Well I found a nice puddle of dye on my garage floor so looking around it I worked out it is coming from the rubber mounting point to the body just under the drivers door. I removed the rubber and plastic clip which holds it and it must have a tiny hole on the larger of the two pipes, I can't actually see a hole or corrosion though? I dried both pipes the first one to get damp again was the larger one, that is my process of elimination? I was thinking of how to bodge to get me through summer but as it is at the mounting point I'm not sure that would be possible? I have found a place in Kettering that can repair AC pipes but I will need to remove it and get it to them. I may give this a try as they guarantee their work. I have also ordered a new dryer in advance of the pipework coming off

Cut the pipe out either side of the clamp a few inches, then insert a new piece of pipe and join with Yorkshire fittings. One option and cheap and easy too.

I assume the AC pipe is the same size as those fitting then, I think 15mm? You can get them without the ribs so could potentially keep it under the rubber mount?

3/4" & 19mm