Air Con not working……

[JohnCalifornia]

I got my AC re gassed when the Cali was in for the MOT around 4 weeks ago at my local VW van centre. When I asked the service manager if there was any leaks on the AC system hence why it wasn’t working in the first place, he assured me there wasn’t and the machine would not fill a system with a leak as it does a test on the system first and would have identified the leak. Is this right? Does the machine do a check on the system first? Anyway the AC no longer blows cold air so something is amiss. Looks like another visit to the van centre with the threat of a diagnostic cost to find the fault……

 

[sidepod]

Possible knackered compressor? No leak, it just doesn’t pump?

 

[JohnCalifornia]

Not too sure, you can hear a bit of a weird noise when you turn the AC on so I assume it’s the compressor . It’s a normal noise that I hear when the AC is turned on in my work van so assume it’s normal. The service manger did say the system was empty when they re gassed it hence why I asked if there was any leaks on the system

 

[JohnCalifornia]

So had the Cali in to the Dealers to find why the AC has stopped blowing cold air just 3 weeks after the system got re gassed. They found a damaged AC pipe that supplies the rear AC system and even better it’s covered on the VW extended warranty. The bad news is that the pipe is on back order and could take weeks to come. Ah well at least it won’t cost me anything and this time round no dirty foot prints on my steps or mats which is a bonus………

 

[andyinluton]

So had the Cali in to the Dealers to find why the AC has stopped blowing cold air just 3 weeks after the system got re gassed. They found a damaged AC pipe that supplies the rear AC system and even better it’s covered on the VW extended warranty. The bad news is that the pipe is on back order and could take weeks to come. Ah well at least it won’t cost me anything and this time round no dirty foot prints on my steps or mats which is a bonus………

Does the front not work with the rear turned off? Thought they were supposed to be totally independent systems.

 

[WelshGas]

Does the front not work with the rear turned off? Thought they were supposed to be totally independent systems.

No, 1 compressor covers both systems. Just one gas system. Important to let a 3rd party mechanic who is regassing/ checking the system that you have the rear AirCon system as the gas volumes and checks are different.

 

[JohnCalifornia]

All I know is that apparently the machine that they use to re gas the system does a 3 stage check before it puts gas in to check that there are no leaks but obviously never found the leaks . I asked the technician why their machine didn’t pick up the leaks but he couldn’t answer me. The original re gas wasn’t cheap at £180 plus vat so if the repair hadn’t been covered by the warranty I would have been asking for a refund of the price of the re gas.

 

[Fergie Collier]

I have the same problem, the rear pipe was replaced in my Cali 4 years ago and its now not working again. Interesting point about the compressor and I suppose it wont be cheap to replace. My garage put dye in to help detect a leak so needs to go back in the garage again. Thanks

 

[vbk1975]

I have the same problem, the rear pipe was replaced in my Cali 4 years ago and its now not working again. Interesting point about the compressor and I suppose it wont be cheap to replace. My garage put dye in to help detect a leak so needs to go back in the garage again. Thanks

The dye is UV, you can buy a very cheap UV torch from Amazon and if you can look in the dark with the torch you will see traces of green/yellow dye that they put in. Our rear pipes failed in the rear arch area under one of the clips, the rear arch lit up with the dye. (This is after VW had it for 2 weeks, 2 visits and 3 special machines said no fault..... and 20 secs with a £7 amazon torch - bingo) - my theory is that our pipe failed under a rubber protected clip and the vacuum test ended up with the rubber sealing the hole as it got sucked on and the leak was small enough that it didn't drop pressure instantly when filled, the dye was the answer to finding it. If the system detects a pressure loss the compressor won't engage - we had a pressure loss fault code if you have a cheap tester.

 

[sidepod]

As with all things, scan for codes.

In my experience the flakiest component is usually the pressure sensor. A scan will confirm.

If failed, it stops the clutch engaging if memory serves.

Basic checks.
Engine on. AC on max.
Check the fans are running.
If yes, confirm the compressor clutch is engaged and spinning.

 

[Fergie Collier]

Thank you very much - I will give it a go.

 

[Alexlex85]

I’d definitely start with VCDS by checking codes and live data on: compressor engagement on/off, compressor load, refrigerant pressure, temperature after evaporator

 

[Fergie Collier]

Thank you - much appreciated.