Air Con intermittent

[eptesicus]

Hi

So the Octavia VRS (mk II 2006) i bought has an air con problem that i need sorting by the dealership i bought it off. It is still in warranty with them and they have agreed to put it right, however as they are a long way away, i can't leave the car there for ages/travel up and down each time for some diagnosing e.t.c

Their service manager is reasonable and said that if i get someone to diagnose the fault they will order the parts needed and fix it in a day while i am there.

On the test drive/s i never noticed it because the air con does work, BUT it sometimes takes ages to start and/or takes some fiddling around with the climatronic controls after driving for a while for the air con to kick in.

Now, i have been doing extensive research into this on the internet and everything points to the refrigerant control valve in the compressor sticking. It seems it is a very common problem with the compressors used in Octavia's/Golfs/Jetta's e.t.c.

Sometimes after putting the engine on the air con will come on straight away(rarely) but most of the time, if the car has been off for a while it will take a good 3-7 miles/10-20 mins for it to come on. When it works, it works fine and is nice and cold.

The compressor is not siezed, as the inner bolt turns and i have run the climatronic diagnostic mode and it's RPM changes with the engine speed e.t.c.

Could it be anything else other than this sticking valve?

One thing i did notice is that one time i looked and had climatronic on auto with the air con on but the front engine fans were not running. Eventually they kicked in and the air con started working, so i was wondering if the fans rely on a signal from the compressor to turn on or whether they should be on as soon as you put the climatronic to auto and start the engine?

For example, if the valve that is possibly stuck was closed would that disable the cooling fans until the valve opened and the air con system started?

Any help would be very much appreciated!

If it needs a new compressor i want it done now, obviously, while it is still covered under a warranty.

Edited 16 September, 2012 by eptesicus

[eptesicus]

Anyone? My biggest question really, is that should the air con/rad fans com on regardless of the valve sticking or not?

I went and started the car this morning and the air con started working straight away, however the fans took about 30 seconds - 1 minute to come on. This worked fine until i pressed 'ECON' and then auto again. The fans then werent running and there was no cold air?

[willingtonsteve]

I have much the same problem on my 2006 petrol VRS. Nobody seems to know much about the compressor unit apart from replace it ! Like you I figure it's a sticking valve problem. Mine has now virtually stopped working altogther although I did hit with a mallet ( if it don't work hit it with a big hammer) the other day and it worked for 50 miles.

[andyvee]

Can you get it scanned with VCDS? This will help tell you where the problem is. The other cause might be the G65 valve - they have a habit of going up the spout as well.

A scan with VCDS should tell you where the problem lies, and you can also run diagnostics on the fans to check they work at both high and low speed.

[eptesicus]

Unfortunately i dont have acess to VCDS so it is going to cost me to have it read. What i really need to know is whether the fans are supposed to come on regardless of whether the compressors regulator valve is in a closed or open position?

Anyone?

I am convinced that the problem is the sticking valve as i read a long thread (granted it was about golfs and jetta's but its the same compressor/engines) and people were having the same issue as me. It took anything from 10-20 mins for the air con to come on most of the time.

[andyvee]

I thought the fans only came on when the compressor was doing some work or the coolant was up to temp. I'll check mine later.

You need to get the fault codes read - there must be a member on here near you with access to VCDS?

[eptesicus]

I thought the fans only came on when the compressor was doing some work or the coolant was up to temp. I'll check mine later.

You need to get the fault codes read - there must be a member on here near you with access to VCDS?

Possibly. Where can i find out if there is anyone near me with VCDS? I live just outside of Woking.

[andyvee]

http://www.briskoda.net/forums/topic/74720-list-of-vag-com-diagnostic-system-vcds-owners/

[phil c]

hi im having the same problem with mine , ive just fitted a new compressor and the fans were replaced six months a go due to running constantly , there are no faults in any system on the car , the actual values in vcds are saying the compressor is working but the pressures dont alter until ive driven the car for about two miles , it then works with out fault until the car is turned off, once restarted it needs to be driven again ? any sugestions ??

regards phil

[aldouk]

I've got this problem too!

When I test drove mine, the guy said he had it recharged the previous year and couldn't understand why it wasn't working, said he rarely used it...

I got it recharged figuring it had a leak, they just said only needed a recharge and charged £40. On the way back from the garage, I had it on and again wasn't kicking in, so I turned around and booted it down the road in disgust ready to give the garage an earful and before I got there, started working!

Now of ebot had it on for a few weeks, nothing in the 5/6 miles I drove today.

I figure it's the same issues as previous posters. Is this control valve easy to replace?

Oh and also when it does work, it sometimes sounds like a fridge (if that makes sense) the pressure building up in the pipes.

[andyvee]

The Fridge sound is normally an indication of a leak and the pressure having dropped. The noise you can hear is the gas expanding in the evaporator.

Sent from my HTC One_M8 using Tapatalk

[Such]

I had the same problem with the hit and miss working aircon. my compressor was eventually replaced, got car back yesterday. Not tested it properly on cold yet as not been hot outside!

[aldouk]

How much is a new compressor? :-/

I'm only doing short trips at moment so can't test it properly.

[Such]

it was replaced under warranty, cost would be around £500 at main dealers, but I think part can be had for around £250

[aldouk]

Ok thanks for that. Guess I'll live with it for now and maybe change the valve first.

Sent from my iPad using Tapatalk HD

[J306TD]

How easy is it to change the valve?

Sent from my Galaxy S5

[andyvee]

Dead easy as it is a Schrader connection, the same as a car tyre valve. The only issue is corrosion as the two different metals react with each other, and it is a little awkward to get to with a spanner.

Sent from my HTC One_M8 using Tapatalk

[J306TD]

Thanks Andy is there a guide on doing it?

Sent from my Galaxy S5

[Guest]

Are you sure you're talking about the same thing...

valve/pressure sensor.

The pressure sensor is easy enough to replace, £22 on eBay.

See my post regarding replacement.

The control valve on the compressor I can't comment on.

[aldouk]

Is it this one?

 

http://www.ebay.co.uk/itm/AIR-CONDITIONING-A-C-PRESSURE-SWITCH-SENSOR-1K0959126B-SUPERB-OCTAVIA-FABIA-NEW-/111422989269?_trksid=p2054897.l4275

 

I've tried a few times this weekend to get mine to kick in, nothing :(

[J306TD]

Is it worth changing even if it's okay?

Sent from my Galaxy S5

[aldouk]

I don't know if it's ok?

It was intermittently working and sometimes taking a little while to come on. Now. Can't get it to come on at all so was hoping for a cheaper quick fix might work...

Sent from my iPad using Tapatalk HD

[rickjw]

Hello guys, did any of you manage to sort out the intermittent air con problem?  I have it, the system has just been regassed and the high pressure sensor replaced. 

It works when you are driving but when stationary it cuts out. 

 

advice and help is much appreciated - and yes I have vcds.

 

Rick. 

 

 

 

[Guest]

I'm in the same boat.

20°C ambient temperature.

I let engine idle for 20 minutes with climatronic on LO, no discernable difference in blower air and all pipework from compressor to condenser unchanged.

I ran engine at 2000rpm for a couple of minutes, no change.

Switched engine off, radiator fans just kicked in as I turned the key and spun down.

Started the engine again and soon the pipework and condenser were pretty hot, fans were on and cabin air was blowing cool.

My condenser is pretty shot so it's ability to shed heat isn't factory spec, I would recommend checking the electrical connection to the compressor. I unclipped mine and cleaned a bit of corrosion/verdigris from the connection.

I'm starting to think that whatever the problem is, it can be temporarily fixed by either high engine rpm or simply cycling the ignition so that if at first it doesn't blow cold, switch off and try again.

[Breezy_Pete]

With VCDS, look at measuring block 2 in the HVAC module. There's a column called Comprossor (sic) Shut-Off which has a non-zero numeric code whenever the compressor has been shut down.

Decode the numbers/find the reason here: http://forums.ross-tech.com/showthread.php?633-Tis%92-the-HVAC-Season.