Air conditioner advice

Hello everyone.

I need your help. I've been having problems with the air conditioning system in my Skoda Octavia (year of manufacture 2006, 103 kW BKD engine, 6-speed HDV transmission) for quite some time.
Approximately 15 months ago, a new compressor was installed, and the system was refilled because it was not providing any cooling.
Shortly after, everything was back to normal, but the cooling gradually became weaker over time.
Additional feature: In autumn weather, specifically with moderate temperatures and humidity, the rear window and the rear side windows will fog up.
However, there was always a perceived cooling performance, which I would estimate to be around 50%.

About 6 weeks ago, I had the air conditioning system refilled because it seemed to be struggling to keep the temperature down when it was above 25° Celsius.
After all the work, it wasn't any better than before...still feeling quite weak in the chest.
Approximately 2 weeks ago, the cooling system completely failed.
According to the measurements, there is a pressure of approximately 8 bar. The compressor is running (at least according to the control panel). There is also a difference in fuel consumption: it's higher when the air conditioning is on.

There was an error code in the control unit, which I unfortunately deleted prematurely.
"Limit exceeded - occasionally."
I believe the component was a refrigerant compressor, but I'm not entirely sure.
Anyway, the error hasn't reappeared, but neither has the cooling performance.

What has changed since the climate failure:
When the air conditioning is on, you can hear a noise coming from the ventilation system. When you switch to "Econ" mode, the noise disappears.

Does anyone have any ideas?

Regards,
Serdar.

serdarg wrote:

When the Klima is on, you can hear a rustling sound coming from the ventilation. When you switch to Econ mode, the noise disappears.

Clear indication of a faulty expansion valve/fixed orifice. "I worked at VW/Audi, and it's always been a weak point."

Thank you, Michael.
Can the valve be replaced by the user themselves?
I know that it's located somewhere after the heat exchanger. Let's consider the possibility of accessing it from the driver's footwell.
Or should I just stay away from it?

Regards,
Serdar.

To make the exchange, the refrigerant lines must be removed - which means the pressure must be released beforehand, otherwise it will make a terrible whistling sound and the area will become extremely cold.

First, you need to have it emptied, and then you can change it yourself. Typically, the expansion valves are located on the partition wall leading to the interior space. You can usually find them by tracing where the refrigerant lines enter the interior; they are often a rectangular "box" through which both refrigerant lines pass.

Okay. Sit down by the firewall. Let's see how I can get there .
Do you need to replace the valve, or can it be cleaned or repaired?
According to a friend, it costs roughly 100 euros.
Sure, here's the translation:

"Just another question, by the way." What is causing the condensation inside?
I've experienced this problem even when the cooling performance was still somewhat adequate.

Regards,
Serdar.

Engine air intake flap defective.

Is there no error entry when there is a defect?

Roger wrote:

Engine air intake flap defective

How is that supposed to work?

Have you ever heard of faulty actuator motors?

Roger wrote:

Have you ever heard of defective actuator motors?

Sure, I've heard that before. But he wrote that he's experiencing some kind of noise or interference. How can that possibly come from a defective actuator?

Hello everyone!

serdarg wrote:

...Just another question, by the way. What is causing the condensation inside? I've experienced this problem even when the cooling performance was still somewhat adequate.

And Roger responded to this

Best regards from Munich!

DieselBär30x wrote:

Hello everyone! serdarg wrote: ...Just another question, by the way. What is causing the condensation inside? I've experienced this problem even when the cooling performance was still somewhat adequate. And Roger responded to this Best regards from Munich!

Oh, I see! He really needs to add that clarification, stating that it refers to this specific question.

So, for me, it was clear...

You always have to talk nonsense .

DieselBär30x wrote:

So, for me, it was clear... You always have to talk nonsense

.
People who have cotton swabs in their cylinders think differently.

serdarg wrote:

Is there no error entry if there is a defect?

It's not always the case; there have been instances where the valve has detached mechanically from the flap, in which case the control unit (STG) sees electrically plausible values and doesn't register anything.

Does the sound of the airflow change as expected when the recirculation button is pressed, especially when the fan is running at high speed? You should be able to see how the switch flips.

@TDI-GTI-4-Motion:

Sorry. I couldn't quote or write novels on the smartphone. If you read serdarg's last post completely, it should still be clear (as DieselBar30x has proven ). I'll probably wait until a computer is within reach next time...

It's always the same two who are causing trouble here .