"Haltbarkeit" von Autoklimaanlagen | Posts 32+

For example, in Renault vehicles (Clio, Megane, etc.), the "design" of the air intakes in the front bumper ensures that the radiator packages rarely last more than 2 or 3 years. They are mostly damaged by stone impacts, and some replacement parts, when installed, corrode due to salt exposure in approximately the same amount of time. The stone impact can be somewhat mitigated by a flat metal grille installed in the lower air intake. In winter, this air intake can be closed off with custom-cut plastic – and it has been proven that the cooling performance does not suffer as a result.

Hello everyone!

ulf wrote:

Bertil wrote: Refrigerant loss in every air conditioning system... that's normal! I understand. But I want to know to what extent I can reduce the refrigerant loss in my Polo through regular AC use

.
@Ulf: No one can give you a well-founded answer to that question with the level of precision you're asking for.
Here's how it starts: Who told you that the refrigerant would leak linearly within the specified 5 years, and not, for example, 30g over the past 4 years, with the rest leaking within a few weeks?
...not always everything, and constantly questioning, also sometimes thinking normally - or at least trying to .

@Bert(i)l: To my knowledge, the values in the linked article, which I have only briefly reviewed numerically, are not really reliable – at least with regard to the constant refrigerant leakage rate in grams.
Also "normal" wird ein jährlicher Verlust von 3% bis max. 10% bezeichnet, abgängig von Hersteller uva. BHappy New Year!
Counter-example: My Quattro, as mentioned in my signature, is now 17 years old, and it still cools better today (with an outside temperature of 36°C) than any newer/current model car that I have tested for this purpose.
Of course, I don't know how much R134a is still in the system, but as long as it's working, nobody is going to mess with it!
Because it's precisely when there are more marketing-oriented than genuinely useful climate services that problems arise, and then that's the end of the good fortune .

@Spati: Off-topic, sit down, sex!

Best regards from Munich!
(of course, from the air-conditioned office ).

DieselBär30x wrote:

... @Bert(i)l: To my knowledge, the values in the linked article, which I have only briefly reviewed numerically, are not really reliable – at least with regard to the constant refrigerant leakage rate in grams. Also "normal" wird ein jährlicher Verlust von 3% bis max. 10% bezeichnet, abgängig von Hersteller uva. BHappy New Year!

With a filling weight between 500 and 800g, a loss of up to 10% results in exactly the 50-80g specified in the article.
The 10% refers to systems with rubber hoses, while 3% refers to systems with fixed piping. Unfortunately, even the latter cannot do without rubber hoses, as there must be flexible sections.
R134a diffuses extremely easily through rubber. This is due to its molecular structure, and it's impossible to prevent.


@ Ulf

Yes, regular operation extends the lifespan of the air conditioning system. I'm not 100% sure if your system in the Polo doesn't already do this automatically. In newer VW Climatronic systems, the control unit automatically activates a "maintenance mode."

Hi again!

I would like to refer you to, for example, SSP 208, page 66, bottom left.
By the way, the text refers to 5 grams per year.

Best regards from Munich!
(...I'm really going to get myself a sweater ).

Hello everyone,

Quote:

Of course, I don't know how much R134a is still in the system, but as long as it's working, nobody's going to mess with it!

I agree... we shouldn't give anyone a chance to unnecessarily break something.

While it's only tangentially related to the durability of modern car air conditioning systems, it's still relevant, so I'll go ahead and continue.

I'm still considering the Polo, though. The air conditioning system cools adequately, although not as well as the Octavia (which is no surprise, since the Octavia is two years old and the Polo is 13 years old, and it's unknown whether or not the A/C system has had any maintenance done). The problem is that there's a noise that's speed-dependent and seems to be coming from the expansion valve (only audible inside the car, and dependent on the A/C load). It's often written that this kind of noise occurs when the refrigerant level is too low, but that's contradicted by the cooling performance, and also by this:

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

The Polo's manufacturing month is MJ2002. While it doesn't fall within the specified VIN range, that range itself is incorrect because, as you can see, it's MJ2003, not 2002 as indicated above. Some users on the Polo forum have experienced this issue with early 9N models, and workshops have often dismissed it as a mere cosmetic flaw. Some owners have driven over 80,000 km with this problem.

Does anyone have more information about this? I'm hesitant to have a system that's generally working well opened up just because of a noise (if that noise is just a cosmetic issue, then it's not a big deal).

Best regards,

Jan.

Quote:

Of course, I don't know how much R134a is still in the system, but as long as it's working, nobody will mess with it!!!

What's the problem? I haven't seen a single Kima system that has become leaky after being filled.
I recently had an Octavia RS here that was lacking 70 grams of refrigerant, which resulted in almost no cooling. After topping it up, it was fine. However, these are modern systems with a modulating compressor.

Before refilling, I read approximately 5 bar of pressure (with the air conditioning off), and after refilling, it was approximately 7 bar.

Hi Grandpa!

The problem lies in the physical vapor pressure of the refrigerant – it's that simple.
In standby mode, it doesn't matter whether there are 3 grams or 3 kilograms (of liquid refrigerant under pressure).
The system pressure remains the same when idle .

Therefore, it is also essential for assessing the situation to extract and weigh the (still) contained refrigerant with utmost precision – always in liquid form.

My problem isn't just related to the quality of the refrigerant being used, but especially to the work practices and, supposedly, the "hygiene" standards of the trained personnel.

In short: As long as it functions satisfactorily, stay away! *I'm saying it again*

Best regards from Munich!
(Okay, the air conditioning is off, and so is the sweater. Time for the sauna *g*.)

Quote:

My problem here is not only related to the quality of the refrigerant to be refilled, but especially to the working methods and, in particular, the "hygiene" views of the supposedly trained personnel. In short: As long as it functions satisfactorily, stay away! *I'm saying it again*

There's not much that can go wrong to damage a properly functioning system. The processes run almost entirely automatically in modern devices.

The issue with the pressure is just an indicator, nothing else. I thought that would be understood as well... The fact that the coolant level can only be determined by weighing it or by the amount that is pumped out is probably self-evident.

Bertil wrote:

@ Ulf Yes, regular operating cycles increase the lifespan of the air conditioning system. However, I'm not 100% sure whether your system in the Polo doesn't do this automatically. In newer VW Climatronic systems, the control unit automatically switches on a "maintenance mode."

So, based on the ~2500 km driven so far, I don't believe there's an automatic maintenance mode, because I almost always drive with the AC completely OFF (all air vents open, fan at zero, display off).
If the compressor were to be activated, it would likely only happen in conjunction with the fan running. And I would notice if the fan suddenly started on its own.
Does the AC maintenance mode have a sophisticated cloaking device?

ulf wrote:

.... If the compressor were to be activated, it would likely only do so in conjunction with a running fan. ...

No, why would I?
You can also operate the heating system without a fan.

Hi!

"The same thing happens with my Golf; the air conditioning compressor only turns on when I activate the interior fan."

I would like to point out that my Golf is 17 years old, has 300,000 km on the odometer, and I have owned it for 7 years.
I haven't done anything to the air conditioning system in 7 years, and it's still working.
As long as that remains the case, I won't do anything about it.

I actually took the climate technology certification exam a few years ago myself.
That also perfectly aligns with what was written in the previous posts, regarding the filling amount and pressure, etc.
Besides all the marketing fluff, they also subtly suggested that as long as the air conditioning system is working, it's best not to mess with it. From a technical perspective, that's the best approach.

Bertil wrote:

ulf wrote: .... If the compressor were to be activated, it would likely only do so in conjunction with a running fan. ... No, why would I? You can also operate the heating system without a fan.

In the AC system, the evaporator could freeze if the "cold" is not removed.
Or can this be prevented by fully opening the expansion valve, so that the compressor doesn't have to pump against any throttling?

ulf wrote:

In an AC system, the evaporator could freeze if the "cold" is not removed.

For this purpose, there is a temperature sensor that would shut off the compressor in time. It doesn't even need to run for long to circulate oil throughout the entire system. Therefore, a complete freezing would not occur.

ulf wrote:

Or can this be prevented by fully opening the expansion valve, so that the compressor does not have to pump against any throttling device?

To the best of my knowledge, our vehicles do not have an electric expansion valve installed. I believe (but I'm not entirely sure) that they often only have a throttle valve, and not even a thermal expansion valve.

Your basic idea is correct and is, for example, used in supermarket freezers for defrosting (hot gas defrost). In this process, the expansion valve (or capillary tube) is bypassed by a solenoid valve, allowing hot refrigerant to be pumped through the evaporator to defrost it.

Greetings.
Guste.

For statistical purposes:

3C.
from issue 2/2007
150,000 km
Just had my first ever climate service check.


490 grams were still remaining.
Refilled with 625g of product and xx ml of oil.

The pop thermometer says it's cooling better now.

m;

guste100 wrote:

As far as I know, our vehicles do not have an electric expansion valve installed. I even believe (but I'm not entirely sure about this) that most of them only have a throttle and not even a thermal expansion valve.

Yes: a few SLPs are telling me, with the absence of an electric expansion valve, that you are probably right.

Steffen G wrote:

Hi! "The same thing happens with my Golf; the air conditioning compressor only turns on when I turn on the interior fan."

I would be surprised if that's a compressor with modulated control, because only those models are supposed to have this maintenance mode.
It really only runs for a short time. Not much gets cold. The main thing is to get the oil circulating evenly and, at the same time, keep the seals supple.


My air conditioning system in my AXR (car model) was hardly ever used (manual control). It was only used regularly during the summer. Once, I heard a loud hissing sound from the system. I refilled the refrigerant, and everything was fine again. The refrigerant loss was minimal.

The DIAVIA cooling system in my Golf 3 1Z, on the other hand, was a disaster. It regularly failed every 2-3 years due to a lack of coolant.