Had A/C re-gassed but still not working

adamtbray

adamtbray

adamtbray

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Joined
21 Dec 2015
Posts
19
Hi guys,

Just a quick question as I took my car to have the A/C refrigerant replaced, as there was no cold air coming out. The issue is that the previous owner of the car had the system repaired and re-gassed only 15000 miles ago, so I was skeptical about whether it was simply needing new coolant.

I took the car to the garage, and asked if they could replace the coolant, and I mentioned regarding any possible leaks to the system being the cause of it not working properly. They said they would be able to test this before putting new coolant in. The question I have is, should they have put more coolant in, and tried to charge me, if there was no leaks in the system, or should they have just checked the compressor, as they basically went ahead with the re-gas, and then tried to charge me the money to do so after finding this wasn't the issue when the system was still not blowing cold air.

I just don't want to be fobbed-off if they should have known before putting coolant in if it didn't need it. I'm guessing you only need to re-gas the system if there are leaks in it? I said I'd head back to the garage tomorrow, but I haven't coughed up any money yet. If they've been reasonable, I'd probably just ask them to investigate other faults with it, otherwise I'll take my car somewhere else.

Any advice would be greatly appreciated.

Thanks,
Adam
 
Great, thanks for the response fellas. I've got the car going back tomorrow so I'll pay for the re-gas and go from there. I guess I should have asked them to check the compressor before a re-gas, but it could be another fault like a sensor I guess? Thanks, Adam
 
It's an Audi A3. I have a feeling it could be a faulty sensor. The windscreen wipers keep stop working intermittently as well now as well, so I'm concerned there is a fault with my car's electrical system. It's only a 2013 car but it's high mileage (120k)
 
Ok, thanks for that. Would they have known how much coolant was in the system before doing the re-gas? I've read the compressor won't work if there's no coolant to stop damage to the system. It's just annoying because he said he would check the system before putting new gas in and trying to charge me for it. Just doing the test you mentioned and checking the level of coolant would have narrowed the problem to the compressor, surely?
 
Thanks, I got it re-gassed at a back street garage. In this instance I should have probably just taken it to kwik-fit for the re-gas. I'm taking it back for diagnostics later today so fingers crossed it will be an easy fix.
 
Ahh I didn't realise the newer ones don't have a clutch. I reckon it'll be the sensor, and I've paid the guy £40 to diagnose the problem with the system. I keep saying I'm going to get a fault code scanner.. it would probably save me a heck of a lot of cash in future, as it feels as if Audi/VWs suffer from a plethora of electrical issues!
 
So the current situation with this is that I purchased a compressor taken from a breakers yard, and I had a different mechanic fit this to the car. It turns out this hasn't fixed the problem, and so the original mechanic misdiagnosed the problem as being the compressor. What a waste of £40 that was! I knew I had good reason not to trust him, and was a good job I took my car elsewhere! After the new compressor failed to work, the mechanic hooked the car up and checked the fault codes with a VAG-COM reader, and unsurprisingly a faulty pressure switch came up. I've had this replaced and the system still doesn't work, however the mechanic informed me the temperature sensor was giving a totally inaccurate readout, which could be a source of the problem. I really don't want to part with any more cash to mechanics, so I'm going to get my own diagnostic scanner and try and source the problem myself. Has anyone else had similar issues with a VAG car?
 
I believe the system has a valve which stops the coolant escaping when replacing the pressure sensor. Yes, the temperature sensor may be a good idea to replace. I'm just wondering if it could be the condenser. How would you diagnose a fault with this? The original mechanic already confirmed there was power running through it, and the new mechanic didn't mention this could be the issue, but I'm just wondering now.
 
I don't think a system leak is the issue here, as if it was a pin-hole leak, the A/C would have worked immediately after the re-gas, which it didn't.

I have a feeling it's a faulty outside temperature sensor, as the mechanic told me it was reading -40 degrees, and from reading online, if this is malfunctioning, this can cause the A/C to fail.
 
Entai said:
Is your car's display showing -40 as an outside temp ?

The AC system uses the same sensor as the cars display.

Even a temp as low as that would not stop the AC system from working at all.
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I don't believe this to be true, looking on another forum re. somebody's Skoda:

"And take note, the outside temp sensor for the aircon (readout in the Climatronic control panel, if fitted) is not the same as the one for the trip computer and engine ambient temperature (readout in clock display)"

Swifty55 said:
If it's climatronic, then I would replace the outside temp sensor as that will indeed affect the system. If it's reading -40c "outside" then it's never going to blow cold air as it thinks it's too cold.
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From what I have been reading it appears this is correct, as the issue is with the outside temp sensor, not the ambient sensor.
 
I have managed to locate the outside temperature sensor, and this is the one which informs the trip computer display, and also affects the A/C, as the A/C light would not come on when I unplugged the sensor. It appears this is working completely fine. Is there another sensor located outside the cabin under the front bumper, or is it the cabin air temperature sensor I need to be locating? It's a pain in the arse a it's the newer shape of A3, there haven't yet been enough failures of the system to see any tutorials/videos. It seems parts are difficult to source as well. May well be a breakers yard job I think. If anybody in the Manchester area has access to a VAG-COM scanner I'd be eternally grateful if I could borrow it to narrow down which sensor it is that is failing!
 
ttaskmaster said:
Does the unit not have a self-test mode like the older Climatronics?#
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It possibly does, but I can't find anything online about it as the model is probably too new for anyone to have written about it. I've tried pressing combinations of buttons on the A/C head unit but haven't had any luck.

Dangerous Dave said:
TBH I would just take it to Audi, they do a fixed price diagnostic fee and will tell you where the issue is. I doubt they would charge a lot to replace a temperature sensor either.
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I guess not, but they always seem to find a way to charge two hours of labour at 80 pounds per hour!
 
Dangerous Dave said:
They have set time to replace parts that they quote on before the work. You can then haggle around 20% off what they quote. I have generally found them cheaper than specialists due to this, a specialist will have half the hourly rate but quote double or more time to replace the parts.
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Yes, I agree now I think about it. You know what you're getting into with the dealership, and they'll actually be able to properly diagnose it. I've bit the bullet and booked it in at Audi. Shouldn't be too expensive if all they're doing is replacing one sensor, as you said.
 
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