Climate control, strange behaviour

Geraldy212

Sportback owner
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When I start the car, the climate control does not seem to work immediately. However, after a few minutes, it suddenly wakes up and produces lots of cold air. I had it re-gassed last week, and when the mechanic had finished he tried to measure the temperature of the air, but again it did not produce any cooling. Then after a few minutes of tick over, the climate control fans started up and again plenty of cold air. I have no chance to do a VCDS scan at the moment. Just hoping someone would suggest what may be wrong. The mechanic thought it might be a temperature sensor. I did post this in the air conditioner section, but did not have any success. Some days, it seems to work as advertised, and the air is very cold when it kicks in. Any suggestions very welcome. Thanks in advance.
 
You need vcds on it to check the MVB's readings, G65 is a good one to check, maybe sticking, £30 part fitted on end of a silver pipe front right bottom of the rad area, also maybe the compressor magnetic clutch is a problem, could be various.
 
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I had this randomly once, Climate Control completely stopped working, no lights or anything for about 5 minutes and then it randomly turned itself on.

Happened once a few months ago and hasn't happened again.
 
NHN, thanks for the suggestions. Yes, I know I need VCDS, and by mid July I should have one on-loan for a few days from a family member. However, I thought that the A3 had a continuously operating compressor (ie. no clutch). At least that is what the Haynes manual indicates. What is the 'MVB'? I assume that the G65 is the high pressure sensor which monitors the refrigerant pressure. Can it be changed without a re-charge?
 
Afaik its magnetic, so engages when you enable via climate button, happy to be proved wrong, but the usual fault with the compressors iirc, is when people don't use them for a long time & the clutch seizes or something, so advice from people is to use every now & then or always, personal preference I guess.

Measuring Value Blocks :)

Yes G65 can be screwed of & back on without a recharge, done it myself multiple times on 8P's.

Usual symptom with G65 is the econ or ac button wont work properly as in econ stays on even when depressed to off for older 8P's & vice versa for facelifts ac button wont light up, but only way to try & track it down as to the fault is with vcds tbh.

Check its plugged in or not dirty connector & its a pita to get to, ideally remove rad but slowly & surely you can do without removal, just don't bend or damage the pipework or you're big time screwed.
 
I'll be keeping my eye on this thread as mine is also doing this. Fans come on full blast but just with outside/hot air being blown then after a few miles it finally kicks in. Makes for a few uncomfortable miles in the hot weather..
 
Have managed to find the G65 sensor. On my A3 it is pointing upwards just to the left of the fan unit (standing in front of the car). I will try to disconnect/reconnect it this week to see if that makes any difference. Looks easy to change by using a box spanner.
 
That's the kiddy, good luck its a bit fiddly getting in there with spanner to turn :)
 

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