what could it be?

J

ja3mie

A3 1.8t Quattro Sport!
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hey people! been getting fed up of my air con/climate control not blowing cold. especialy in this heat!

so today, i checked the gas (expecting it too be low) but it had plenty of gas in it! no leaks etc..

but the compressor does not kick in?

is there a fuse or anything protecting the air con circuit? thanks
 
air con machine :)

is there anything common on the a3?

cheers
 
Few things to check, one being the fuse for the compressor circuit. Other possibilities are a faulty low pressure switch, a blocked expansion valve/orifice tube, a blockage somewhere in the pipework, or a blocked receicer/drier. The fuse is easy enough to check. The blockages can sometimes be sorted by having the system vacuumed down for at least an hour to suck out all debris/moisture etc. If a blockage is diagnosed, I would most definately renew the expansion valve after any clearing of the system. Always good to change the receiver/drier after a few years too.

When you say you checked the system and it had plenty in. Can I ask how you checked it and how you know it has plenty in? Lets say the system is supposed to have 525grams of R134a in, but it only has 180grams in. Anybody will think there is possibly enough in if they were to press down on one of the port valves, because the refrigerant will escape at a great rate of knots, making you think it's ok. A system that low (180g when it should be 525g), will not work properly, if at all.
 
they were a little low at first, with the engine running about 5 bar each side, i then removed refrigerant, vac'd for 20 minutes and put in 800g of gas. this made no difference what so ever. obviously done the leak test after the vac too which come up ok!

do you know where the fuse is?

thanks alot. jamie
 
800g :scared2: Thats too much. The aircon wont work with too much in. The high pressure relief switch will not allow the compressor to pull in. It'll be permanently tripped. I dunno which A3 you have but it shouldn't be any more than 550grams or thereabouts. Is there not a sticker on the slam panel with the correct amount on? If you give me your cars details (just year and engine size and code), I'll check in my bible ;), how much should be in there. Pity you're not a bit closer to me, I'd have it sorted in a jiffy for ya :sm4:

EDIT: Just seen the details of your car under your avatar!
 
750-800g is whats meant to go in according to autodata?

its a V reg quattro mate :)
 
Do you have access to VCDS, that told me what my aircon problem was just need someone to fix it now:beerchug:
 
ja3mie said:
750-800g is whats meant to go in according to autodata?

its a V reg quattro mate :)
Click to expand...

ahhhhh, right :respekt: I was just assuming it was a couple or so years old lol. Well there's always the possibility that the compressor is kaputt.
 
I have an odd issue with mine too.

With the climate on and on any other setting other than 'Lo' it blows hot then cold then hot so it wont blow out at one constant temp other than when its set to low.

I can hear something whirring away but no idea what it is or how to get to it. Its pretty annoying!
 
Going warm and cold alternately is a classic sign of moisture in the system. What happens is, the water in the system freezes up at the orifice tube/expansion valve and ice globules block it up, your air momentarily goes warm, the ice then melts and cold air resumesand it keeps cycling like that. The remedy is; new receiver/drier, and a long long vacuum down (90 minutes would be good) to really suck out all the moisture. That will fix your problem, I guarantee you.
 
Fuses on top of the battery (3 x 30amp ones) are a typical problem... the fuse used for the after run pump, fan controller etc goes wiggy and corrodes causing the fans not to cut in and the aircon not to work..

IMAG0658.jpg


<tuffty/>
 
My fuse did that too! Didn't melt but had a naff connection, rad fans and air con didn't work - but the air con controller was quite happy and no faults reported!
 
cheers for the input guys!

will go have a check of them fuses when i can actualy be bothered to get out of bed! lol

i hope it is something like that and not the compressor or something!
 
I take it you have the 20mm condensor as opposed to the 16mm then Jamie?
 
im not sure tbh Gary. i have not really looked into, i just thought at first i was likely to have a leak. But obviously now its gassed and still not working thats why im here :D

the fuse checking hasnt gone too well at the minute.. im still not up and ready! lol
 
gary3306 said:
Going warm and cold alternately is a classic sign of moisture in the system. What happens is, the water in the system freezes up at the orifice tube/expansion valve and ice globules block it up, your air momentarily goes warm, the ice then melts and cold air resumesand it keeps cycling like that. The remedy is; new receiver/drier, and a long long vacuum down (90 minutes would be good) to really suck out all the moisture. That will fix your problem, I guarantee you.
Click to expand...

thanks very much for that, I've been scratching my head over it for ages. Any ideas on the cost for that little lot?
 
A3Tom said:
thanks very much for that, I've been scratching my head over it for ages. Any ideas on the cost for that little lot?
Click to expand...

£30 ish for the R/D and then a few hours labour at whatever the place that you get to do it charges. Maybe £150 ish.
 
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