Air con issues

[dannyboy75]

Just as the warm weather's returned, my air con stopped working this morning

It's been behaving a bit strangely for the last 3-4 weeks, whereby for the first few minutes after starting the car, the vents would sometimes blow hot air unless the system is set to LO. In other words, just changing it from LO to 16 was enough to change it from cold to hot (not warm) air. After a few minutes it would sort itself out though. This issue was intermittent and I can't say I'd really noticed it in the last week or so.

However, today it's just stopped making cold altogether, and I can't hear the audible click of the compressor kicking in which I'm sure I could previously. I've checked fuses 1 and 6 - not sure which is the relevant one - but both look fine anyway.

I had it all regassed about 6 months ago, and even a couple of days ago it was icy cold. I guess it could be a leak, but then I would've thought the ECON light would be on all the time (it isn't), as this was the case when the coolant system was emtpy for a few months last year.

Could there be anything else at fault here? It might just be my imagination, but I'm sure the side vents feel a little cooler than the centre ones. I wouldn't describe any of them as cold, but the outer ones are definitely slightly cooler.

 

[B5NUT]

Could be the compressor that has failed, I know a couple of people with B7's that have had them replaced.

 

[Paul B7]

Could be the compressor that has failed, I know a couple of people with B7's that have had them replaced.

My cars a/c showed similar symptoms and I had a seized compressor, Ouchhhhhhhhhhhhhhh!

 

[hades-]

could be LP sensor
get it on vcds to rule out any sensor faults
then free aircon check at kwik fit

 

[dannyboy75]

Thanks guys. Will get it checked at Kwik Fit first then. Really hoping it's not a seized compressor, as I'm guessing they're a) not repairable, and b) very expensive to replace.

 

[Paul B7]

Thanks guys. Will get it checked at Kwik Fit first then. Really hoping it's not a seized compressor, as I'm guessing they're a) not repairable, and b) very expensive to replace.

When my low pressure sensor failed the Econ Light was on all the time.
When my compressor seized the econ light stayed off.
Cost for a replacement Compressor at Audi ( five years ago ) was £860 (replaced under the Audi warranty).

Good luck and I hope its a cheap fix !

 

[dannyboy75]

Urrrgh. Thanks for the good luck wishes. I don't have a good feeling about this though!

If its not a cheap fix (and if hitting it with a hammer fails) then I think it'll be bye bye audi, as this'll be the second four-figure repair bill on this car in a year or so. Think I might go back to Fords - cheaper to run and cheaper to fix!

 

[ruairi83]

there is second hand units on ebay for £150

 

[dannyboy75]

Thanks, I'll have a look. I assume there's a fair bit of labour involved too, plus regassing costs etc?

 

[B5NUT]

It's a simple job to remove and refit, it can be done in under 30 minutes. The leak test & regas will take longer (about an hour), and should cost no more than £50.

 

[dannyboy75]

Well I had my MoT yesterday, so I got the guy to have a quick look into the air con issue while he had the car. It's not a refridgerant leak, as the system has plenty of pressure. The compressor and clutch are also spinning, so those seem OK. And the LP sensor seemed OK too, it's getting power and no errors on VCDS.

However, what he did notice is the fan isn't coming on when the air con is switched on (i.e. when the Econ light is off). So he said it could be the fan control module, so I'm going to check the fan motor itself later just to make sure that's OK. If it is then I guess that only really leaves the control module, so the local scrappy could be my next port of call.

Does anyone know the correct part number I'd need for a 2005 petrol B7?

thanks