Air Con service... or Con?

[n968412L]

Just had a mail shot from the VW dealer who did my 20k service six months ago offering to do a 2 year service on the air con... which could be fine as the car is now 2 years old. What does the team think? Worth doing?
Thanks
M

[cai]

What is air con?

[n968412L]

Air conditioning... the temperature control of the cabin air... is this another phrase that doesn't translate across the atlantic...

[Jxander]

Just had a mail shot from the VW dealer who did my 20k service six months ago offering to do a 2 year service on the air con... which could be fine as the car is now 2 years old. What does the team think? Worth doing?
Thanks
M

It really depends on what they offer for the money. A pressure check of the system and adding necessary freon is always good to do every now and then. With our Phaetons a detailed look at the VW computer diagnostics on the system might also be in order. Cleaning the condensor and evaporator and making sure the condensate drain is clear are also things that might be done.

If they truly take the time to do these things and don't merely give it a pass because it functions well, it might be worth $150 US or so. Note this is not part of VW recommended servicing. However, they do recommend, "Dust and Pollen Filter – replace every 2 years if driven less than 40K miles." So I would definitely insist on this if it has not been done. In fact, it could be this service that they are referencing as an AC service.

[PowerDubs]

If it is not broke, don't fix it.

I would put anything offering a top off or refill under the category of scam.

Refrigerants are made up of several chemicals of various densities. If there were to be a leak in the system to allow a discharge, the gasses leak out at different rates. This means that the remaining gases are are an improper ratio. The correct way to fix this would be a complete discharge, repair of the leak source and a proper recharge.

[chrisj428]

Mike,

I know, historically, a proper evacuate and recharge on the 4.2 V8 has proved to be beneficial. It certainly wouldn't be a bad thing on the 3.0TDI, especially if you find the system may not be cooling as well as it once did.

However...

I caution you against them performing any disinfectant/deodorisation services as the in-dash temperature sensors are situated in such a way as to render them particularly vulnerable to damage from aerosols being introduced through the air con intake.

[n968412L]

Thanks Chris - as a recognized VW dealer, I think they should be trusted not to do anything harmful... and at £75, given all the other costs on a P, I think I'll do it!

[jkuisma]

Refrigerants are made up of several chemicals of various densities. If there were to be a leak in the system to allow a discharge, the gasses leak out at different rates. This means that the remaining gases are are an improper ratio. The correct way to fix this would be a complete discharge, repair of the leak source and a proper recharge.

The way the air conditioner is "serviced" or "topped up" (around here in Europe, at least) takes care of this properly. All certified AC workshops have a service cart on wheels. It has hoses which are used to hook it up to the car's AC. The automatic service cycle begins with a complete discharge of the gases in the system. The unit will weigh the amount of gas there was in the system. The technician is then supposed to find out the right amount for this particular car being serviced. Once it is entered into the device, it will refill the AC with exactly the right amount of refridgeant. (here's one such cart: http://www.robinair.com/products/detail.php?id=2370 ) This kind of device will also take care of vacuuming the system (to remove moisture if the system has been opened and exposed to atmosphere) and leak testing.

It is normal behavior of a perfectly working car's AC system that the refridgeant will eventually find its way out through the numerous seals in the system. Normally, the owner will notice a degradation in cooling effect in five years or so. By that time, the system may already have lost tens of percents of the refridgeant. Eventually the gas pressure will get so low that the underpressure switch of the AC system will prevent the compressor from engaging. Then it is no more AC until the system is refilled again. This will cause no harm as long as there is some pressure left in the system, preventing outside air and moisture entering.

It is a common practise of the industry (at least around here) that the AC systems are recommended a "topping up" - meaning a proper discharge and refill to a recommended charge - every two years. This is, in my experience, a slight overkill. But you should definitely "top up" every four years, at latest, to keep the system performing well. This is assuming the AC is in good shape and there are no leaks (others than which are evident by the design of the system).

It is also recommended that the drier component of the AC should be replaced every now and then: definitely every time any component of the system has been replaced, but also with regular intervals, every few years or so. This is usually neglected and in my opinion it is a waste of money as well. Some AC technicians have a strong opinion on this, though.

75 pounds / circa 100 euros is pretty standard price for a proper AC service. Some charge extra for the gas they need to add to the system.

The "DIY" refridgeant refill cans are not available for sale in Europe. This is due to the greenhouse emissions legislation of EU. Only trained AC technicians are legally allowed to repair the system.

In my experience (I am only an amateur what comes to AC, having retrofitted a system once and serviced my own AC's for a decade) things get pretty complicated when something really goes wrong with the AC. Once you need to start replacing components in the system (a defective compressor, for example) you will need to know/estimate how much oil you need to add to the system to ensure proper lubrication of all components but without harming the AC effect. If a component seriously fails (compressors are prone to this in VW's circa 2004-2007) you may end up with small metal particles in the coolant circuit which will eventually clog up the expansion valve and cause a lot of other problems. I had this happen on my 2007 EOS and the VW workshop spent nearly two days dismounting most of the AC components from the car and carefully flushing them free of metal chips. Fortunately, this notoriously failing VW compressor is not used in the Phaeton.

[PeterMills]

Fascinating, and useful thanks.

The beauty of this forum is that people find time to set out in detail information like this.

Long may it last.

PETER M

[n968412L]

The beauty of this forum is that people find time to set out in detail information like this.

Long may it last.

Hear hear!!

[WillemBal]

The airco of my P doesn't seem to work as it should, on the first warm day of the year (23 ºC outside). It produces more vent than cool air. According to VAG-COM, there is a persistent fault, coming back about 50% after clearing the DTC's:

Address 08: Auto HVAC Labels: User\3D0-907-040.lbl
Control Module Part Number: 3D0 907 040 F
Component and/or Version: Climatronic D1 1144
Software Coding: 0000001
Work Shop Code: WSC 50709 124 02615
VCID: 2142E7DAC793FC14
1 Fault Found 00445 - Loss of Refrigerant

Most convenient fix seems to be offered by a nearby car HVAC service centre. Price for flushing and replacement with R134a refrigerant is 99 Euro. I will check VW pricing tomorrow. I wouldn't go to a service centre for tyres and exhausts, but HVAC seems to be pretty standard. My question is, whether it is safe to let an HVAC service centre do the job? Are there any strict procedures, other than usual for "normal" cars?

Willem

[lucatambu]

If it is not broke, don't fix it.

Wrong in this case, IMHO. A proper maintenance will avoid you to "fix it"

From my experience, i suggest you all to discharge/recharge the AC every 2 years, even if it works flawlessy. The basic point is that the oil lube (that is always charged with the gases) slowly degrade, if you don't do the job the main risk is to grind the compressor. I'm a professional driver, i always pass 300K km with my cars, never had a problem with AC system, just doing the proper maintenance every 2 years ... i recommend the VW service BTW

[WillemBal]

I checked "normal" VW dealer price, quoting 129 Euro including VAT, which sounds OK to me. They recommend to have this done every 3 year. What they do is just drain all refrigerant then vacumize, because adding refrigerant to a cooling system with an unknown amount of refrigerant poses the risk of filling more than the required quantity. There is no means to tell how much there is, as the pressure will always indicate the vapour pressure, almost regardless of refill amount. So they refill the system after draining with the prescribed weight of refrigerant and that is basically it. They also offer an additional cure for removing odd odours, caused by bacteria.

Willem

[n968412L]

They certainly added something to kill the bacteria - but it made the car smell like a hospital for about six weeks. Was not pleased!

M

[johnt26]

Hi All,

My wife complained about the A/C not functioning as it should on our first very hot day (95F).

VAG-Com shows the same 00445 loss of refrigerant code as Willem had. It still blows cool air but I'm sure it's not at the 7C temperature it should be.(I'll measure it tomorrow)

Willem, did you trust the car to a HVAC shop or take it in to VW?

I am trying to build a rapport with my local import garage as they seem very good and are walking distance from my house. They have done some work on my other cars.

On my classic Porsche I have to add a bit of R-134 once a year because it does seem to leak down, it was converted from R-12. Reading this thread, it doesn't sound as if I should fool with that method on the Phaeton.

Besides, after reading the self study programme on the HVAC system linked here, it appears that the system may have been stolen from an alien spacecraft with its complexity!

Thanks for any suggestions.

[WillemBal]

Hi All,
My wife complained about the A/C not functioning as it should on our first very hot day (95F).
VAG-Com shows the same 00445 loss of refrigerant code as Willem had. It still blows cool air but I'm sure it's not at the 7C temperature it should be.(I'll measure it tomorrow)
Willem, did you trust the car to a HVAC shop or take it in to VW?

I am trying to build a rapport with my local import garage as they seem very good and are walking distance from my house. They have done some work on my other cars.

On my classic Porsche I have to add a bit of R-134 once a year because it does seem to leak down, it was converted from R-12. Reading this thread, it doesn't sound as if I should fool with that method on the Phaeton.

Besides, after reading the self study programme on the HVAC system linked here, it appears that the system may have been stolen from an alien spacecraft with its complexity!

Thanks for any suggestions.

Hi John,

My airco also worked either for 50% of not at all. So I called my regular VW dealer (not the Phaeton dealer) and asked for a refill. They said that they are allowed to work on Phaeton's for simple tasks like this one and that they have all the necessary equipment including the repair manual, which states the procedure and the exact amount of refrigerant to be used.
They also said that they first empty the system, then refill with a known quantity of R134, as there is no means to tell the filling level. The only measurement would be pressure, but the pressure you measure is basically the saturation vapour pressure of the refrigerant (pump off), which remains constant no matter how much there is, until the last drop is used up.
My dealer did a good job; it's functioning perfectly. They said the recommended service cycle for replenishment of the refrigerant is 3 years (in NL).
By the way, the name R134 is not some mysterious name for a secret mix of liquefied gases, but is a code, which says something about the amount of C, H and O in the structural formula. It is a pure hydrocarbon liquid.
Personally, I think that any airco service centre could do the job, but the price that the (regular) VW dealer asked was perhaps 15% higher, so that did it for me.
Johh, when you suspect a leakage, other than natural disappearance by means of diffusion or migration through seals etc., I suggest that you tell the VW dealer about it. Then they do a leak test. To facilitate easy leak finding, my refrigerant contained a fluorescent material, which lights up in a UV light. I don't know if this is standard, otherwise they will have to use some other method to determine whether or not there is a leak.

Willem

[johnt26]

Thanks Willem,

I think it's just the "time" to do a vacuum and refill on mine and I'll see what happens.
Thanks!

[EnglishPhaeton]

They certainly added something to kill the bacteria - but it made the car smell like a hospital for about six weeks. Was not pleased!

M

Hi Mike,

could you let me know the dealer that serviced the Air Con for you, and how long did they need the car?

Cheers
Stu

[johnt26]

Just as an update, my local shop did the service, everything is working great now.

[n968412L]

Just noticed this on a scan I did today...

-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 3D0-907-040.lbl
Part No: 3D0 907 040 J
Component: Climatronic D1 2031
Coding: 0000001
Shop #: WSC 01065 000 00000
VCID: 254AFF1FE8FA271

3 Faults Found:
00716 - Air recirculation Flap Positioning Motor (V113)
014 - Defective - Intermittent
00229 - Refrigerant Pressure
002 - Lower Limit Exceeded
00445 - Loss of Refrigerant
000 - - - Intermittent

-------------------------------------------------------------------------------

Does this mean just a cheap trip to VW dealer... or something more exciting (expensive?)

Stu - I realise when looking up this thread that I didn't tell you that the air con service that was done (must be almost two years ago). Can't quite remember - but I think I left it with them for an afternoon. Didn't like the smell it left...

Regards

M

[WillemBal]

...Does this mean just a cheap trip to VW dealer... or something more exciting (expensive?)...

It could be pretty dull... when all of these faults occurred once, long ago and the DTC's weren't erased for a long time. Then it is just a matter of erasing the DTC's and wait and see...
To make things a little more exciting, I would suggest to run an adaptation procedure on your HVAC. This will exercise all flaps and relearn their end positions.

With your VCDS, enter the HVAC control module (08). Enter the Adaptation module. Shortly after entering, you will see a text balloon with instructions. Follow thse instructions and wait what will happen. For about a minute, you will see some strange things happen, louvre vent covers opening halfway, etc. Hopefully this will keep your recirculation flap motor DTC away for a long time.

About your suspected leakage... I remember seeing a sticker on mine, in the engine compartment, saying that a fluorescent dye had been added to the refrigerant. Then leakage problems can be spotted more easy using a UV lamp. I don't know whether it is standard practice to add this dye or whether it is only added when a leakage problem is suspected.

Willem

[n968412L]

Thanks Willem- I'll be contacting a dealer sometime soon.

Anyone in GB know where three is a list of VW dealers with certified Phaeton techs? I thought I'd seen one once... but can't find it now.

Regards
M

[EnglishPhaeton]

Thanks Willem- I'll be contacting a dealer sometime soon.

Anyone in GB know where three is a list of VW dealers with certified Phaeton techs? I thought I'd seen one once... but can't find it now.

Regards
M

Mike,

I know that Lookers in Darlington have one!

Stu

[rv02tx]

I need some direction on locating the "expansion valve" on my 04 Phaeton W12. The technician said it was clogged but that service shop will not open a unit on vacuum to clean and refill and that's how he diagnosed the problem. The compressor is good and another parts are ok at 85,000 miles

The way the air conditioner is "serviced" or "topped up" (around here in Europe, at least) takes care of this properly. All certified AC workshops have a service cart on wheels. It has hoses which are used to hook it up to the car's AC. The automatic service cycle begins with a complete discharge of the gases in the system. The unit will weigh the amount of gas there was in the system. The technician is then supposed to find out the right amount for this particular car being serviced. Once it is entered into the device, it will refill the AC with exactly the right amount of refridgeant. (here's one such cart: http://www.robinair.com/products/detail.php?id=2370 ) This kind of device will also take care of vacuuming the system (to remove moisture if the system has been opened and exposed to atmosphere) and leak testing.

It is normal behavior of a perfectly working car's AC system that the refridgeant will eventually find its way out through the numerous seals in the system. Normally, the owner will notice a degradation in cooling effect in five years or so. By that time, the system may already have lost tens of percents of the refridgeant. Eventually the gas pressure will get so low that the underpressure switch of the AC system will prevent the compressor from engaging. Then it is no more AC until the system is refilled again. This will cause no harm as long as there is some pressure left in the system, preventing outside air and moisture entering.

It is a common practise of the industry (at least around here) that the AC systems are recommended a "topping up" - meaning a proper discharge and refill to a recommended charge - every two years. This is, in my experience, a slight overkill. But you should definitely "top up" every four years, at latest, to keep the system performing well. This is assuming the AC is in good shape and there are no leaks (others than which are evident by the design of the system).

It is also recommended that the drier component of the AC should be replaced every now and then: definitely every time any component of the system has been replaced, but also with regular intervals, every few years or so. This is usually neglected and in my opinion it is a waste of money as well. Some AC technicians have a strong opinion on this, though.

75 pounds / circa 100 euros is pretty standard price for a proper AC service. Some charge extra for the gas they need to add to the system.

The "DIY" refridgeant refill cans are not available for sale in Europe. This is due to the greenhouse emissions legislation of EU. Only trained AC technicians are legally allowed to repair the system.

In my experience (I am only an amateur what comes to AC, having retrofitted a system once and serviced my own AC's for a decade) things get pretty complicated when something really goes wrong with the AC. Once you need to start replacing components in the system (a defective compressor, for example) you will need to know/estimate how much oil you need to add to the system to ensure proper lubrication of all components but without harming the AC effect. If a component seriously fails (compressors are prone to this in VW's circa 2004-2007) you may end up with small metal particles in the coolant circuit which will eventually clog up the expansion valve and cause a lot of other problems. I had this happen on my 2007 EOS and the VW workshop spent nearly two days dismounting most of the AC components from the car and carefully flushing them free of metal chips. Fortunately, this notoriously failing VW compressor is not used in the Phaeton.

[snapdragon]

I always take my cars to a local vehicle refrigeration specialist.
Their main line of business is buses, coaches and refrigerated trucks.

For £10-30 depending who I see and whether the boss is there, they connect a manifold with meters to the high and low circuits and run the engine and the CC is on LO LO. They also stick a thermocouple deep in an interior vent.

They watch the needles on the meters and keep adding a little R134a and watching the thermometer.

They seem to know when the needles will change before they do and say things like, you see this needle is rising now, your fans will go high any second now and sure enough they do.

He said that the places with the wheel-in trollies are OK, but don't know what they are doing, they just wheel the machine up, plug it in and press go, it has to evacuate and refill the system because they don't know enough about refrigeration to make any decisions themselves.

They said if it needs topping up more than every 4 years, there is probably a leak and these are nearly always on the condenser in front of the radiator. It gets hit by stones and other debris. He said spray soapy water over it and look for cuckoo spit. No need to run the engine or a/c.

They also said when you wash the car in winter, hose the salt out of the condenser fins with water.

[jkuisma]

They watch the needles on the meters and keep adding a little R134a and watching the thermometer.

This is how it used to be done back in the "good old R12 days" BUT it is old-school and not recommended any more. This is because the newer refridgeants behave differently and the gauges do not give you accurate information on the fill level. R134a gas should always be filled by weight. This is exactly what the modern AC service carts do. First, they evacuate all gas from the system. Next, they refill manufacturer-specified amount of gas, by weight.

Jouko

[snapdragon]

This is how it used to be done back in the "good old R12 days" BUT it is old-school and not recommended any more. This is because the newer refridgeants behave differently and the gauges do not give you accurate information on the fill level. R134a gas should always be filled by weight. This is exactly what the modern AC service carts do. First, they evacuate all gas from the system. Next, they refill manufacturer-specified amount of gas, by weight. Jouko

While I agree with the technical argument, in practice, I have given up with the wheel-up trolly places due to poor outcomes/price vs good outcome/price of the specialists.