Secret air conditioning sequence? R36 2008

[Screwdriverone]

Hi all.

With warmer weather on the way, I wanted to ask if anyone knows the special secret aircon sequence that actually makes the air come out cold when you start the car and set the aircon to high when the car has been in the sun and is hot?

It often takes about 5-10 mins of driving before cold air comes out of the vents. it even stops blowing cold periodically after it starts to cool, as if the compressor is cycling off for some reason.

I have tried turning off the climate control completely and cycling the a.c. on and off and even directing manually to the face vents and putting it on 16deg (LO) and nothing seems consistently workable.

is there a cabin sensor fault or some other issue? Or is it simply the asthmatic euro style aircon?

gas is not the issue as it was regassed in Jan of this year and DOES get cold, although not consistently enough on start up when the car is hot.

Any ideas? No errors on the system through OBD2.

Cheers,

Chris

2008 R36 Reflex Silver Wagon

[Screwdriverone]

Could it be this? Control Valve replacement? Sounds like it could be the reason for the slow turn on?

VW Jetta and Golf sanden ac compressor control valve replacement | VW TDI forum, Audi, Porsche, and Chevy Cruze diesel forum

[Domatron]

Mine does a similar thing. Sometimes takes a minute or 2 for cold air to come out and you can here the tone of the air flow change when it does.

Sent from my SM-G955F using Tapatalk

[3C4M Guy]

Mine has been highly variable this past week during the hot weather in Melbourne. Sometimes it blows cold air within half a minute and few hundred metres. Other times I can drive for 4-5km over 10 mins+ with just warm, humid air coming out the vents before it finally starts to blow cold air. It does not seem to be related to external temperature. The system has plenty of gas. Seems like something sticking on occasions. TX valve? Other control mechanism?

[Vee]

Mine was doing the smae thing, compressor was on the way out. $1,400 later its fixed.

[JustCruisn]

My Jetta is slow to get cold also, if it sits idling it will never get cold. I find I need to drive it then it gets cold quite quickly. Not sure if it is an engine speed or an air flow thing.

[Old Navman]

Screwdriverone,

It sounds just like the symptoms I had experienced with my a/c system. The bad news - IF you're unlucky you might have to buy a new compressor. In that case I wouldn't go to VW to get it fitted as the unit itself I believe costs around $1300 plus fitting. I'd get same compressor type (brand) from an independent on-line retail outlet (read the bay or a local OEM seller) Whether Sanden or otherwise you can buy it much cheaper than from the dealer. IF you're lucky and it's just the compressor controller valve you're winning there. You can not buy just the controller valve from Oz VW just because they don't stock it but same is available for about U$80 from US suppliers. Alternatively, you can take a chance and get your a/c mechanic to evacuate the gas and take a picture of the controller valve noting any part numbers. 99% chance you can buy that controller for about U$40 from china and get your a/c mechanic to refit it and re-gas the system. That is what happened to me and all told cost me under $200 to evacuate the gas, buy the controller valve and have the system re-gassed. Works perfectly, I get almost instantaneous cold air and after about 5 min the temp will get down to about 5C. Before it could be 10 or 30 min before I got any cold air out and it would only get down to about 10C . (Attached images of compressor showing location of the compressor controller valve and the controller valve - note you should send a photo of your actual controller valve to o/seas supplier to ensure you get the right one) Hope this helps.

[Screwdriverone]

Screwdriverone,

It sounds just like the symptoms I had experienced with my a/c system. The bad news - IF you're unlucky you might have to buy a new compressor. In that case I wouldn't go to VW to get it fitted as the unit itself I believe costs around $1300 plus fitting. I'd get same compressor type (brand) from an independent on-line retail outlet (read the bay or a local OEM seller) Whether Sanden or otherwise you can buy it much cheaper than from the dealer. IF you're lucky and it's just the compressor controller valve you're winning there. You can not buy just the controller valve from Oz VW just because they don't stock it but same is available for about U$80 from US suppliers. Alternatively, you can take a chance and get your a/c mechanic to evacuate the gas and take a picture of the controller valve noting any part numbers. 99% chance you can buy that controller for about U$40 from china and get your a/c mechanic to refit it and re-gas the system. That is what happened to me and all told cost me under $200 to evacuate the gas, buy the controller valve and have the system re-gassed. Works perfectly, I get almost instantaneous cold air and after about 5 min the temp will get down to about 5C. Before it could be 10 or 30 min before I got any cold air out and it would only get down to about 10C . (Attached images of compressor showing location of the compressor controller valve and the controller valve - note you should send a photo of your actual controller valve to o/seas supplier to ensure you get the right one) Hope this helps.

Thanks ONM. it sounds like this is what I need to do. I had the gas checked and topped up and the problem is still there and/or worse. I am hoping it's the valve.

Cheers,

Chris

2008 R36 Reflex Silver Wagon

[Screwdriverone]

Update: I have done the Climatronic A/C flap re-alignment sequence by turning on the car (starting the engine) then press the A/C button and the face vents buttons simultaneously which activates ALL segments of the LCD screens and runs the flap initialisation sequence (thanks to Kamold) and after it returns to temperature display (around 30 secs) I am now getting cooler (if not cold) air through the vents.

Yesterday in 45 degrees all I got was BLASTING HOT air from the system no matter what I did.

I also suspect that the coolant is too full, so am planning to evacuate the system and refill with 650g of R134A at my local aircon specialist to see if this makes it go full cold.

Once that is done, if the problem is not fully fixed, then I suspect an RCV valve needs replacing on the compressor.

Anyone have any links to suppliers in Aus or OS? All references I follow seem to be outdated links. Old Navman? do you still have the link for where you bought yours?

Cheers

Chris

[Passat my07]

I think I priced one up through speedy air spares in qld. I didn't ever get around to buying it though because the car got written off.
Have you scanned the car to check the climate control temp sensors etc?