Aircon Problems - Not always cold, temperamental, long to kick in and then drops out

[doridori]

Hi,

I have a 2010 Jetta 125 TDI with factory MK6 climate controls and my airconditioning has been playing up.

It is now quite erratic and does what it wants to do in terms of regulating the temperature.

Note for the below, i've always manually set the temperature to the lowest rather than rely on the auto climate control and is on recirculating mode.

Sometimes when i turn it on, the system will take 5-10 minutes before it start putting out cold air even if the car was stored in cool underground parking so it's not heatsoak from the sun.

This will then continue for a little while then the cold air stops being cold and just starts blowing out slightly cool air which may or may not be just ambient air. After 5-10 minutes (sometimes longer) the cold air will start pumping through again.

At no point in time were any AC controls changed and this could occur on the highway, city or wherever.

Does anybody have any idea what the issue could be?

Is it the compressor? When it does pump out cold air, it's pretty cold and works as it used to. It just doesn't like doing it continuously.

if i have the setting on 22C, the unit sometimes can't decide if it wants to give me cold air or warm air.

I have reset the flaps on the system (by holding the AC button and front vents until the lights flash but that doesn't always work.

Thoughts?

[arcadelt]

Aircon Problems - Not always cold, temperamental, long to kick in and then drops out

Get the compressor checked ASAP. I have a 2010 Tiguan that was exhibiting the same behaviour from my purchase some years ago. I ignored and have driven the compressor to destruction, which now requires replacement of the compressor and another major parts, plus a full flushing of the system. You may just get away with replacement of the compressor, a much cheaper option. BTW, two air conditioning specialists tell me this is a common fault in this vintage VWs.

[doridori]

Ah ok thanks for that. Was yours doing the same thing?

It still blows cold air so I’ve been wondering if it’s something else which regulates the temperature or if it really is the compressor.

Any suggestions for shops in Sydney?

[arcadelt]

Aircon Problems - Not always cold, temperamental, long to kick in and then drops out

Yes. I let it go because I thought the climatronics was just crap, but I have been told VW climate control is actually very good.

I don't live in Sydney.

[doridori]

thanks for that mate

anybody else have some experience or know shops around Sydney?

[whichonetoget]

Is it true that all VWs of this vintage (MK5 era) will have faults with the A/C??

[doridori]

well in the end i just had my normal servicing workshop get it fixed and i believe they outsource it to someone else.

Cost me $1000 to replace the compressor and flush the lines.

not gonna say that a lot of mk5s have AC errors, but my 2nd car, a 2008 r32 now also have aircon issues

[jets]

Is it true that all VWs of this vintage (MK5 era) will have faults with the A/C??

My '06 Golf TDI has had no problems with the AC. That said, I live in a moderate climate of low humidity & only turn it on when needed.
Some drivers, I have noticed, never turn there's off so naturally it will wear out faster.

[whichonetoget]

Can you guys recommend me someone is Sydney that can look at my A/C?

Just bought a MK5 GTI where the A/C is now blowing air only. I note that it was re-gassed in 2015 with it only recently dying again...

[asa572]

Is it true that all VWs of this vintage (MK5 era) will have faults with the A/C??

My '06 Golf TDI has had no problems with the AC. That said, I live in a moderate climate of low humidity & only turn it on when needed.
Some drivers, I have noticed, never turn there's off so naturally it will wear out faster.

220,000+ klm's on my MKV and the only issue I have had with the ac was the temp sensor in the centre of the on-off dual buttons.
My ac is never off.

[Pussbak]

I have a 2009 R36 and it takes 5-7 minutes for the air to kick in. Doesn't matter if its been in the garage all day or out all night. Once it comes in its cold as and will stay cold.
In trouble shooting I have turned the car on and let idle then monitored the AC lines in the engine bay. When the larger line gets cold the air is cold but it does take 5-7 minutes.
This is the same for warm air also.
Its really annoying since you need conditioned air for demisting the windscreen and so frustrating sitting on the road side waiting for the AC to kick in.

Im guessing the compressor is OK since once it kicks in it's fine.
Perhaps low on gas or a pressure switch failure.
It's not an intermittent fault but happens every time i start the car after its been sitting for more than say 1 hour.

Any feedback is welcomed and appreciated... Cheers

Sent from my SM-G900I using Tapatalk

[arcadelt]

Im guessing the compressor is OK since once it kicks in it's fine.

Don’t take anything for granted.

Any feedback is welcomed and appreciated...

Go and see an air conditioning specialist sooner rather later. See my post above for the reason why - don’t be that guy!

[Pussbak]

Don’t take anything for granted.



Go and see an air conditioning specialist sooner rather later. See my post above for the reason why - don’t be that guy!

Thanks arcadelt for the reply.
The hunt begins for a GOOD AC guy, someone that has experience with the VDubs and wont just tell me to regas it and see what happens.

Sent from my SM-G900I using Tapatalk

[s900t8v]

I'm a saab guy but have been working on a vw. Usually the main cause for compressor failure is low refrigerant. The oil needs adequate refrigerant volume to circulate and there is a slight cooling effect of the working parts of the compressor by the refrigerant that has changed state after going through your evaporator. The way to determine if your refrigerant is low is usually by checking the sight glass. Or alternatively watching to see if the compressor clutch is engaged from the moment you turn on the switch in the cabin.

If the compressor clutch is engaged and you aren't getting cold air straight away it could be a few problems the most common is low charge. Or a sticking thermostatic expansion valve I've just rebuilt and regassed my own ac in my 84 saab with hychill so have a fair understanding of the setup. That being said there are lots of faulty signals that can prevent ac from working . Like full throttle deactivation. Engine heat deactivation. High pressure deactivation or low pressure deactivation. You can tell if these are working if you're seeing your ac compressor cycle on and off rapidly or not cycle on at all.

I don't have much faith in genuine diagnoses by ac guys. Good money is to be made in Aus by ac guys given the voodoo status it has. But it's really pretty simple system to trouble shoot. Provided you don't have a leak of oil there's no harm in trying an evacuation and Regas. And most of the time it's just because the hoses and o rings leak a small amount of refrigerant over the years as the materials degrade.

[Passat my07]

The problem is these cars don't have a compressor clutch. They are a variable stroke compressor. The solenoid valve can fail so they won't alter the stroke.
The compressors also don't mind destroying themselves and filling the system with metal. That's probably why the pros prefer to just fit a new compressor and be done with it.